UNEP: Atlas of Our Changing Environment
United Nations Environment Programme

UNEP Atlas of our Changing Environment
An introduction to UNEP's Environmental Atlas Products ..
Atlas of Our Changing Environment
Introduction
|
UNEP: Atlas of our Changing Environment documents environmental changes around the world with historical satellite images, ground photographs, maps, and narratives based on the latest environmental science. Specific examples of environmental change are brought into focus at over 180 locations around the globe, each marked with the UNEP icon (). At each location the user can overlay images on the Google Earth surface which highlight recent environmental changes. Changes, including retreating glaciers, melting polar ice, dramatic urban growth, disappearing lakes, disappearing forests and dramatic land use change, are presented in the rich geographic context of Google Earth.
It is a time of increasing concern about the impact of human activities on our planet. This presentation in Google Earth helps us all to make the connections between local actions with global impacts and global changes and local impacts. The user is invited to follow the links to the UNEP webpage where they can find more information about specific sites and can contribute to discussions of environmental change on our blog.
Much of the content presented in UNEP: Atlas of Our Changing Environment is drawn from the hardcover publications One Planet, Many People: Atlas of Our Changing Environment, Africa's Lakes: Atlas of Our Changing Environment and Africa: Atlas of Our Changing Environment.
Learn More About the Atlas Publications
2008-2009 United Nations Environment Programme

Addis Ababa
Google Earth 4.2+ is required to view this KML.
If you are already using Google Earth 4.2, please note that this placemark's balloon description cannot be edited using the placemark's property window as this KML uses advanced and techniques. See this link for more information.
Please install the latest version of Google Earth to view this KML. You can find it here:
http://earth.google.com
Addis Ababa, the capital of Ethiopia, was established in 1889. Major urban migration into the city began in the mid-1970s, driven mainly by unemployment, poverty, and declining agricultural productivity in rural areas. The population of Addis Ababa is currently 2.9 million, and is projected to grow to 5.1 million by 2015.
Ethiopia as a whole has an annual population growth of 2.8 per cent. Twenty-seven per cent of Ethiopia’s urban population lives in Addis Ababa and this has created substantial pressure on the city’s infrastructure, housing, and urban services. These satellite images taken from 1973 to 2005 show the development of Addis Ababa’s massive urban sprawl.
In 1996, the city had only 238 000 residential housing units. That same year, the total number of households was estimated to be 460 000, leaving 220 000 households or nearly 1 000 000 residents without suitable housing. This situation led to illegal housing construction and uncontrolled settlements, some of which are encroaching on protected forest and reserve lands at the edges of the city.

Akagera National Park
Google Earth 4.2+ is required to view this KML.
If you are already using Google Earth 4.2, please note that this placemark's balloon description cannot be edited using the placemark's property window as this KML uses advanced and techniques. See this link for more information.
Please install the latest version of Google Earth to view this KML. You can find it here:
http://earth.google.com
United Republic of Tanzania, Uganda, Rwanda
Akagera National Park in northeastern Rwanda is considered to be among the most complex savannah ecosystems in eastern Africa. Across its landscape are areas of tangled acacia trees interspersed with patches of open grassland, patches of gallery forest in the north, and wetlands and lakes along the course of the Akagera River.
Fire is common in the savannah portions of the park. Fire tends to maintain the savannah’s vegetation structure, composition, nutrient cycling, and distribution. Satellite images from July 1980, June 1984, July 1999 and July 2004 show the area surrounding Akagera National Park with large fire scars (dark purple patches). In 1980, fires left a scar 35 km wide and well over 100 km long. In 2004, fires burned nearly one-third of the park; they are believed to have been set by poachers. In contrast to these dry season images, the December 1999 image shows the region during the rainy season, when fires occur infrequently.
The size of Akagera National Park was reduced by approximately two-thirds in 1997 to allow for the resettlement of large numbers of refugees. Heavy grazing pressure, agricultural encroachment, charcoal production, the felling of trees for fuelwood and construction, and deliberately set fires have seriously fragmented the ecosystem. Wildlife populations are now concentrated in scattered enclaves.

Al Wahda Dam
Google Earth 4.2+ is required to view this KML.
If you are already using Google Earth 4.2, please note that this placemark's balloon description cannot be edited using the placemark's property window as this KML uses advanced and techniques. See this link for more information.
Please install the latest version of Google Earth to view this KML. You can find it here:
http://earth.google.com
The second-largest dam in Africa and the largest in Morocco, Al Wahda Dam has a capacity of 9 714 million m3. Located in the Gharb Plain, the dam was built in 1996 to reduce devastating flooding along the Ouergha River, provide water for irrigation, and generate hydroelectricity.
Since completion of the dam, flooding has decreased by 90 per cent, potential irrigation has increased by about 110 000 ha, and hydroelectricity production has reached approximately 400 Gwh per year. The electricity produced by the dam allows the Moroccan government to avoid burning 140 000 metric tonnes of fossil fuels per year, thereby reducing greenhouse gases released into the atmosphere.
However, natural and human-caused erosion is filling the dam with silt and threatens its long term sustainability. It is estimated that the reservoir loses 60 million m3 of capacity each year to siltation. In addition, these sediments trapped in the reservoir do not reach the coastal estuary, which has altered the balance of siltation and erosion along the coast in favour of erosion. Another potential threat to the dam’s future viability is suggested by climate and hydrological modeling, which predicts that a 1° Celsius increase in average air temperature between 2000 and 2020 might reduce runoff to the Al Wahda Dam by 10 per cent.

Almeria
This pair of satellite images shows the impact of massive and rapid agricultural development in Almeria Province along Spain's southern coast. In the earlier image, the landscape reflects rather typical rural agricultural land use. In the 2000 image, much of the same region-an area covering roughly 20 000 hectares (49 421 acres) - has been converted to intensive greenhouse agriculture for the mass production of market produce. (Greenhouse-dominated land appears as whitish gray patches.) In order to address increasingly complex water needs throughout Spain, the government adopted the Spanish National Hydrological Plan (SNHP) in 2001. Initially, this water redistribution plan involved the construction of 118 dams and 22 water transfer projects that would move water from parts of the country where it was relatively abundant to more arid regions. In 2004, the Spanish government announced it would begin exploring more environmentally friendly water-saving technologies, such as wastewater recycling and seawater desalinization.

Al’Isawiyah
Rich in oil but lacking abundant water resources, Saudi Arabia has used oil revenues to adopt some of the best technologies available for farming in arid and semi-arid environments. One such technology is the center-pivot irrigation system (CPI). In satellite images, CPI-irrigated fields appear as green dots.
These Landsat images, from 1986, 2000 and 2004, reveal the effects of this irrigation strategy in a vast desert region in Saudi Arabia known as Wadi As-Sirhan. This region was once so barren that it could barely support the towns Al’Isawiyah and Tubarjal that can be seen in the upper left of each image. Following the introduction of center-pivot irrigation, however, barren desert was gradually transformed into a greener, food-producing landscape.
The irrigation system draws water from an ancient aquifer-some of the water it contains may be as much as 20 000 years old. Judicious use of water resources, and climate-appropriate technology, has in this situation helped improve food production without being detrimental to the environment.

Amatole Mistbelt Forests
While forests are not believed to have ever covered a large part of South Africa, logging, clearing for agriculture, and forest plantations have much reduced their original extent. Indigenous forests now cover only 0.33 per cent of South Africa’s land area.
South Africa’s Amatole Mistbelt Forests are part of the southernmost areas of Afromontane forest in Africa. They contain some small remaining patches of indigenous forest. These forests fall within the Maputaland-Pondoland-Albany biodiversity hotspot and are home to variety of unique plant and animal species, including several endemic species such as the endangered giant golden mole (Chrysospalax trevelyani). They are also important resources for local people who rely on them for wood and non-wood products. Some of the characteristic tree species are yellowwood (Podocarpus falcatus), red currant (Rhus chirindensis), and black ironwood (Olea capensis).
South Africa’s Department of Water Affairs and Forestry defined the areas of Isidenge and Pirie as “irreplaceable” patches of indigenous forest. While nearly half of the forests in the Amatole Mistbelt Forests are under state management, less than 1.5 per cent are under strict protection. Comparison of these 1972 and 2001 images shows some new areas of tree cover; however, these are primarily plantation forests of pine and eucalyptus, which threaten to alter the hydrology and reduce the biodiversity of these ecosystems.

Angangueo
The Oyamel Fir forest of Angangueo, central Mexico, is an important habitat for wintering Monarch butterflies. Because this forest occurs within the tropics at high elevation, it provides a relatively stable microclimatic envelope that protects the butterflies from freezing on cold nights during the five month overwintering season. Adiabatic rainfall together with fog condensation on the fir and pine boughs provides the moisture that prevents the butterflies from desiccating as the dry season advances. A comparison of the 1986 image to the 2001 image reveals that parts of the forests have been degraded severely. The two close-up images (below) serve to illustrate the most affected areas. In these images, the unaffected forest is green in colour while the degraded area is tan. In spite of two presidential decrees intended to protect this area, it is estimated that between 1984 and 1999, 38 per cent of the forest area has been degraded.

Anjouan Island
Comoros’ population quadrupled between 1950 and 2000. On Anjouan Island, where population density of is 446 people per square kilometre, agricultural land is in short supply and many areas of steep terrain not suitable for agriculture have nevertheless been cultivated. Traditional agriculture leaves many trees in the fields, which help control soil erosion. However, pressure for food production is leading to more open field agriculture and some monoculture farming on the island of Anjouan. These more intense methods of agriculture encourage soil erosion. The image shows areas with little tree cover on the island's steep slopes - most of these areas have been or are being farmed. As a whole, Comoros lost about 60 per cent of its forest cover between 1950 and 1985.

Aral Sea
The name "Aral Sea" comes from the word "aral" meaning island. The sea's name reflects the fact that it is a vast basin that lies as an island among waterless deserts. The Aral Sea was once the world's fourth largest inland sea. Its problems began in the 1960s and 1970s with the diversion of the main rivers that feed it to provide for cotton cultivation in arid Soviet Central Asia. The surface of the Aral Sea once measured 66 100 km² (25 521 square miles). By 1987, about 60 per cent of the Aral Sea's volume had been lost, its depth had declined by 14 m (45 feet), and its salt concentration had doubled, killing the commercial fishing trade. Wind storms became toxic, carrying fine grains of clay and salts deposited on exposed sea floor. Life expectancies in the districts near the sea are significantly lower than in the surrounding areas.
The sea is now a quarter of the size it was 50 years ago and has broken into two parts, the North Aral Sea and the South Aral Sea. Re-engineering along the Syr Darya River delta in the north will retain water in the North Aral Sea, thereby drying the South Aral Sea completely, perhaps within 15 years.

Arkhangelsk
The Arkhangelsk region is situated in northwestern Russia, where its 3 000-km (1 158-mile) coastline is washed by the icy waters of three Arctic seas; the White, the Barents and the Kara. The area's proximity to the ocean contributed to its early settlement and subsequent development. The Arkhangelsk region was once cloaked with dense boreal forests. In comparing these three satellite images, however, the widespread forest cover disturbance is obvious. In some places, large sections of the forest have been clear-felled and the trees completely removed. Other places show a block pattern, where sections of relatively undisturbed forest are left between clear-felled sections to enhance reseeding and reforestation. In a number of areas, networks of minor access roads delineate the forest cover. The region is also home to the Plesetsk Space Center and has been impacted by fire and pollution from falling rocket stages. Overall, forest cover in the Arkhangelsk has been heavily disturbed-even within areas designated as nature sanctuaries.

Atatürk Dam
Built in 1990, the Atatürk Dam on the Euphrates River in southeastern Turkey is the centrepiece of the Southeastern Anatolia Project. The Atatürk Dam is the largest in a series of 22 dams and 19 hydroelectric stations built on the Euphrates and Tigris Rivers in order to provide irrigation water and electricity to this arid region of the country. When the project's entire system of reservoirs, power generation stations, and irrigation channels is operational (projected to occur in 2010), the irrigation of approximately 1.7 million hectares (4.2 million acres) of land will be possible.
In these two Landsat images, acquired in 1976 and 1999, respectively, the transformation of the region around the dam is strikingly apparent. The dam's reservoir reached capacity in 1992 and has supplied sufficient water for irrigation to turn a once-arid landscape into a green one. This is especially obvious in the lower right-hand corner of the 1999 image, where irrigated fields completely surround the town of Harran. The development of the Harran region could not have occurred without the Atatürk Dam project, especially since the town is many kilometres from the river.

Athabasca Oil Sands
Vast reserves of low quality oil underlie the boreal forest surrounding Fort McMurray in northern Alberta, Canada in the form of "Athabasca oil sands." While these reserves have been known since the early 20th century the high cost of extracting usable oil from these "oil sands" limited the development of a viable oil sands mining industry. In 2003 the rising cost of crude oil led the Oil and Gas Journal to formally recognize Canada's oil sands as a viable resource (Woynillowicz et al., 2005). The oil held in these reserves raises Canada to second place on the list of oil rich countries, behind only Saudi Arabia in total reserves (Oil and Gas Journal, 2004).
The rising price of oil has fueled this oil boom in Northern Alberta. Canada's National Energy Board predicts $125 billion in investments for creation and expansion of oil sands mining in the Athabasca area between 2006 and 2015 which will take production to around 3 million barrels per day (National Energy Board, 2006). Local people including the Native American population are concerned that exploitation will come at too great a cost to the environment. The government of Alberta plans to propose a surface mining area of 280,000 hectares, "an area approximately four times the size of the City of Calgary" (Mineable Oil Sands Strategy-Government of Alberta, 2005). In 2001 oil extracted from oil sands (271 million barrels) exceeded oil extracted by conventional means (264 million barrels) for the first time (Canadian Centre for Energy Information, 2002-2003).
In 1967 The Great Canadian Oil Sands Company began construction at its Mildred Lake site. In 1974 they were joined by the Syncrude Corporation which began construction of a mine in the same area. By early 2006 the mining operations had expanded to cover an area roughly 30 km by 20 km. Syncrude operates a second mine, the Aurora, approximately 30 km to the north of Mildred Lake.

Baban Rafi Forest
Along the southern border of Niger in the Department of Maradi, population has increased by roughly 400 per cent over the past 40 years. The area under agriculture in the department as a whole grew by 26 per cent between 1975 and 1996. In the south of the district, this expansion of population and agriculture has meant the loss of a large portion of the Baban Rafi Forest to agriculture. The remaining woodlands are being degraded by overexploitation for fuelwood and non-wood forest products.
Baban Rafi Forest is the most significant area of woodland in the Maradi Department. Located at the southern extreme of the Sahel, it has areas of both savannah and Sahelian vegetation. In the savannah areas, the balance of trees, grasses, and shrubs varies. The wooded areas are dominated by just four species of trees—Guiera senegalensis, Combretum micranthum, Combretum nigricans, and Acacia macrostachya—likely as a result of selective exploitation and some combination of drought and disease.
These satellite images show the loss of a significant fraction of the natural landscape (darker green areas) of Baban Rafi Forest to agriculture between 1976 and 2007. The intensity of demand for agricultural land has also led to near continuous use of farmland in the area, with shortened or no fallow period for it to recover fertility. The lighter areas are where the woodland savannah vegetation has been cleared for farming. Continuing population growth will put further demands on this already dramatically changed landscape.

Balanta Rice Farming
Rice is a major crop and staple food in Guinea-Bissau. The production of paddy, or “wetland,” rice started in the late 17th and early 18th centuries, when the Balanta (the country’s largest ethnic group) started organising men and women for agricultural production. Rice paddies (yellow outline) have replaced many of the mangroves along the Gêba and Mansôa Rivers to the north of the capital, Bissau.
These rice paddies are built by cutting a path through the mangroves and piling up mud to form a dike that will keep back the tide. The mangroves, cut off from the ocean, quickly die. The ground is then burned to clear remaining undergrowth. After the paddies are constructed, their walls trap rain water, in which rice will grow.
Navigating along the Gêba and Mansôa Rivers in the Google Earth browser, dark green belts of mangrove forests can be seen adjacent to the rivers throughout the area. Intensive rice farming is indicated by the light-grey areas bordering these mangroves. Only isolated patches of mangroves (deep-green) remain in much of the area.

Bangassou Forest
The Bangassou Forest is a mosaic of lowland rain forest and secondary grasslands in southeastern Central African Republic covering an estimated 1.2 to 1.5 million hectares. This region is very isolated; little is known about its forests and there has been no commercial exploitation of the forest products in this area. While this is not a protected area, there has been oversight from the regional Office of Water and Forests and a community conservation project. The Bangassou Forest is an area with high biodiversity and a wide range of habitats.
Only about 20 000 people live in the forest itself; however, the city of Bangassou has a population of over 24 000. The growth of Bangassou and the apparently increasing gaps in the forest canopy between 1975 and 2006 (light coloured areas, particularly between Zipo and Madamboya) suggest that pressure on the forest may be increasing.
The Bangassou Forest is one of only two areas in Central African Republic where elephants still live. Estimates of the elephant population have declined from 2 640 in 1989 and 1 600 in 1995 to perhaps as few as 500 to 1 000 in 2004. This is widely believed to be the result of poaching which appears unlikely to decrease under current circumstances.

Banjul
The Gambia’s capital city, Banjul, is located at the end of a peninsula referred to as Banjul Island or St. Mary’s Island. Banjul grew rapidly until the early 1980s, when commuter services from the surrounding area were developed. Easy access to Banjul led to dramatic population growth in the nearby Kanifing District, from less than 12 000 in 1963 to over 332 000 in 2003. The pattern repeated itself as the Kanifing District became crowded in the mid-1990s and services and amenities were made available in the areas south of Kanifing, inducing many people to move there.
The sprawl of greater Banjul has led to the loss of forest cover and arable land. It is also putting increasing pressure on the Tanbi Wetland Complex, a mangrove forest located between Banjul and Kanifing District. Tanbi was recently designated a Ramsar Wetland of International Importance. These images show the dramatic increase in urban development in the Banjul area between 1973 and 2006, particularly in the Kanifing District. Some forest blocks (deep green patches) have survived; most of them are designated forest reserves. The Abuko Nature Reserve, immediately southwest of the Tanbi Wetland Complex, increasingly contrasts with the developed areas around it. The Reserve was set aside in 1916 to protect a water catchment and was made a nature reserve in 1968.

Beijing
Beijing, the capital city of the People's Republic of China, is located in the country's northeastern corner, in the transition zone between the Inner Mongolia Plateau and the North China Plain. It is a city that has undergone tremendous change and explosive urban growth, since the start of economic reforms in 1979.
The left-hand satellite image shows Beijing in 1978, just prior to the reforms. The light blue-gray area in the center of the image is the urban landscape of the city. The hills to the west are covered with deciduous forest, which appears green. The agricultural lands that lie around the city appear as muted red, orange, and golden yellow, depending on the crop (rice, winter wheat, or vegetables) and its stage of development. Beijing's explosive growth is very obvious in the 2000 image. The city has expanded from its original center in all directions. Prime agricultural lands that once lay outside the city are now suburbs dominated by institutional, industrial, and residential buildings. In 2000, Beijing's population was 13 million.

Beira Fire Scars
During Mozambique’s dry season—May to October—fires leave burn scars on the landscape. Over a third of the country is affected by fire each year. NASA’s Earth Observatory recorded an especially large number of fires in August 2006. The widespread nature of the fires suggests that they may have been intentionally set. Population growth in Mozambique has drastically intensified the need for agricultural land as well as for forestry and wildlife products, thus putting increased pressure on limited resources. Fires have become a primary means of clearing land for cultivation.
The 21 May 2006 satellite image was acquired at the beginning of the 2006 dry season, before many fires had left their mark. The 9 August 2006 image shows the same area roughly 2.5 months later. Pink, dark red, and black fire scars cover much of the landscape.
Many plants in Mozambique are adapted to periodic fire. However, the increasing frequency of fires affects the natural regeneration of vegetation and is believed to be reducing species diversity in Mozambique’s forests. Frequent fires can also increase soil erosion and negatively impact hydrology.

Beki Forest Reserve
Located in southeastern Côte d’Ivoire, Beki Forest Reserve was one of 230 forest reserves established in the country in 1965. In 1971, Beki Forest Reserve covered 16 764 hectares. By 1986 its forested area had decreased by about one-fifth to 12 816 hectares. In 1995, less than one-third of the 1971 extent remained, representing an annual rate of loss around 4.5 per cent.
Much of this deforestation began in the 1980s when the government resettled two villages away from the Comoé River and adjacent to the Beki Forest Reserve. The villages had been afflicted with an outbreak of onchocerciasis (river blindness) carried by blackflies that live near fast flowing water. To facilitate the village resettlements, authorities allowed the villagers to exploit land within the Reserve. Unfortunately, no limits were set on this authorized exploitation, and by the mid-1990s cultivation of cocoa and coffee covered much of the original forest area. In the images above, decimation of Beki Forest Reserve is apparent between 1986 and 2003, in contrast to the Bossematie Forest Reserve to the southeast.
In Côte d’Ivoire, cocoa plantations currently cover two million hectares, and have caused the loss of a significant portion of the country’s natural forests. Côte d’Ivoire produced 1.275 million metric tonnes of cocoa in 2004/2005. Coffee and cocoa generate 50 per cent of the country’s total export revenues and one-third of the population depends on cocoa cultivation.

Bou Craa
The Bou Craa phosphate mine is located 100 km inland from the capital city of El Aaiun. The Bou Craa area’s phosphate resources were discovered by the Spanish in 1947; phosphate deposits are near the surface and are very pure. Phosphate mining, however, did not begin until the 1960s. Since 1974, the Bou Craa mining operation has been growing steadily. In 2000, the mine covered more than 1 225 hectares. In 2001, its output was approximately 1.5 million metric tonnes of phosphate.
Morocco controls the area of Western Sahara where the mine is located and jointly operates the mine with Spanish interests. While the mine amounts to only two or three per cent of Morocco’s phosphate production, the reserves are valuable because of the uranium that can be extracted from them.
The phosphate-containing rock is transported from the Bou Craa mine to the port at El Aaiun via a 100-km-long conveyor belt, which can move 2 000 metric tonnes of rock per hour.

Brasilia
Inaugurated on 21 April 1960, Brazil's new capital of Brasilia began with a population of 140 000 and a master plan for carefully controlled growth and development that would limit the city to 500 000. Urban planner Lucio Costa and architect Oscar Niemeyer intended that every element - from the layout of the residential and administrative districts to the symmetry of the buildings themselves - should act in harmony with the city's overall design. This consisted of a bird-shaped core with residential areas situated between the encircling "arms" of Lake Paranoá. The city was a landmark in town planning and was recognized as a World Heritage site in 1987.
As these images reveal, unplanned urban developments arose at Brasilia's fringes resulting in a collection of urban "satellites" around the city, at the cost of much of the forested area. Several new reservoirs have been constructed since Brasilia's birth, but the National Park of Brasilia stands out as a densely vegetated expanse of dark green that has remained relatively unchanged. In 1970, the population of Brasilia and its satellites was roughly 500 000. The population now exceeds 2 000 000.

Breidamerkurjökull
During much of the 20th century, Iceland's Breidamerkurjökull Glacier has been shrinking. It has been studied extensively since 1903, when researchers drew up detailed maps which showed that its base is just a few hundred metres from the ocean edge. Over time, the glacier has receded so that its base is now several kilometers from the coast. As the huge river of ice pulled back across the Icelandic landscape, thousands of hectares of fertile farmland have been exposed, and people are populating the area that was until recently buried under tonnes of ice.
In this pair of satellite images, notice how the glacier has receded and the glacial lake at its tip has enlarged over time. Some researchers attribute the shrinking of Breidamerkurjökull to climate change and global warming. Other scientists maintain that the glacier is simply retreating from the advance it made during the Little Ice Age.

British Columbia
Temperate forests tend to be found in midlatitude areas and are characterized by well-defined seasons with warm summers and cold winters, with precipitation that is sufficient for tree growth. The same regions of the world in which temperate forests occur are also home to large numbers of people. As a result, temperate forests constitute one of the most altered biomes on the planet. Only scattered remnants of the Earth's original temperate forests remain today, some of which still contain stands of trees that are in high demand for their valuable wood. The interior of British Columbia is a perfect example. Logging is a major industry in British Columbia, carried out almost exclusively in virgin forest, which is very rich in endemic biodiversity. This pair of satellite images of the Fraser River Valley in British Columbia shows the impact of logging and other human activities during a period of about 25 years, from 1973-1999. The heavy exploitation of the forest is evidenced by the "patchwork quilt" appearance that is typical of logged-over areas.

Bujumbura
With 91 per cent of its people living in rural areas, Burundi is one of the most rural nations in Africa. It is also the second most densely populated. Approximately 90 per cent of the work force relies on agriculture, the vast majority being subsistence farmers. Some of the most intense agriculture in Burundi surrounds the growing capital of Bujumbura. A comparison of 1979 and 2000 satellite images shows the expansion of agriculture around the capital.
Adequate rainfall and good soils have historically made Burundi self-sufficient in food production. However, many areas in Burundi are considered unfit for cultivation. Scarcity of land will continue to put pressure on farmers to cultivate unsuitable lands. Burundi’s domesticated land use has been measured at 86 per cent; a country is generally considered to be “land scarce” when 70 per cent or more of its land is used. Better agricultural practices could improve productivity and might relieve some of the pressure to convert additional unsuitable land to agriculture.

Bumba
A pattern of deforestation concentrated along the local roads in the Nord-Ubangi and Mongala provinces of the DRC can be seen clearly in the 1975 image as loops of light green through the otherwise dense rain forest. In the 2003 image, these deforested corridors have widened, almost to the point of joining. Most of this deforestation is the result of agricultural conversion, fuelwood collection, settlement, and artisanal logging. Networks of logging roads can also be seen within two of the patches of largely intact forest in the lower right corner of the 2003 image.
While industrial logging has had a relatively small impact in the DRC in the past, it has recently become the most extensive form of land use in Central Africa. More than half of the area visible in these images is under logging concession. The selective logging practised by commercial logging companies has been shown to have long-lasting impacts on forest composition. Logging roads have been shown to significantly increase bushmeat hunting.
In addition to local and logging roads, a recent study for the World Bank suggests the road from Bangui, CAR, to Kisangani, DRC, be improved as part of a continental road network. The study shows that the network would increase trade on this route enormously. It also acknowledges concern that parts of the road network that would experience the greatest increase in trade correspond to areas with the highest biodiversity.

Cairo
Cairo is the largest city in Africa, ranked by urban population, and Egypt is the third most populous country. In 1850, Cairo’s population was only 250 000; 80 years later it had reached one million. Growing continuously, the population of the Cairo metropolitan area increased from less than six million in 1965 to more than ten million in 1998. Estimates of the city’s current population vary widely, with some reaching as high as 16 million people.
The Nile River is the lifeblood of Egypt as it is the main source of freshwater for household use and irrigation, a source of power from the hydroelectric facility at Aswan, and a means of transportation for people and goods. The only arable regions in Egypt are the green floodplains that line the Nile River.
Phenomenal population growth in the 20th century has resulted in the loss of much of the critically needed arable land around Cairo to urban development. The urban extent of Cairo (dark gray areas) expands dramatically between the 1972 and 2005 images, both into the Arabian Desert to the east and into the lush agricultural areas (green) surrounding the Nile. Most of Cairo’s physical growth, particularly its unplanned or informal settlements, has been concentrated on agricultural land.

Campo-Ma’an Forest
The Campo-Ma’an rain forest in southern Cameroon covers approximately 770 000 ha of an area known as the Guineo Congolian Regional Centre of Endemism, a species rich area of rain forest with many species found no where else in the world. While the population density is quite low the area supports a host of economic activities, many of which threaten the area's ecosystems including logging, shifting agriculture and commercial agroforestry. These forces contribute to southern Cameroon's high rate of deforestation which is among the highest in central Africa.
In the 1973 image, the forest appears largely intact. By 2001, rubber and palm plantations dominate the landscape. These large-scale agro-industrial operations have replaced approximately 7.5 percent of the area's forest cover. In addition, commercial forestry in the natural forests, and shifting agriculture put further pressure on the natural landscape.
The Campo-Ma’an area is an important focus of conservation efforts in Cameroon and in 2000 Campo-Ma’an National Park was created to protect its diverse flora and fauna. The park covers 26 400 ha of diverse forests spanning from the Atlantic coast to roughly 100 km inland.

Catoca Diamond Mine
The Catoca kimberlite pipe (a type of diamond-rich geological formation) in the Lunda Sul province of Angola is the world’s fourth largest in terms of surface area, with diamond reserves of at least 40 million carats. The Catoca Mine was constructed between 1994 and 1997. In 2003, the mine produced 2.5 million carats worth US$ 189 million.
Mining, by its very nature, significantly alters the landscape. Satellite images from 1990 and 2006 show the extent of change at Catoca over that 16-year period. Diamond mining is a large-scale earth-moving operation—for each carat recovered, more than a tonne of material is moved. Diamond mining is also extremely water intensive, since water is used to wash the final gravels and separate the diamonds.
The Catoca Mine was built to minimize its environmental footprint. Its current extraction methods produce little toxic waste. The next stage of the project, however, will use dense media separation (DMS) for diamond recovery, a chemical process that exerts a far greater environmental impact.

Challawa Dam
The Challawa Dam in Kano State, Nigeria, was built to control flooding caused by seasonal and variable rainfall and to support irrigation. It also supplies water to Kano, Nigeria’s third-largest city with a population of seven million. The Challawa River feeds into the Hadejia River, which then flows into the Hadejia-Nguru wetlands. Local rainfall peaks in August, with a subsequent dry season lasting from November to April. This rainfall pattern makes water levels in the Hadejia-Nguru wetlands highly seasonal.
The Challawa Dam has tamed highly seasonal downstream flooding at the expense of the Hadejia-Nguru wetlands. The combined effect of drought and the dam reduced the extent of seasonally flooded land from 300 000 hectares in the 1960s to between 70 000 and 100 000 hectares in recent years. Such severe reduction of the annual flooding extent has put the wetlands at risk and reduced the economic and environmental benefits they provide, including agriculture, cattle, fuelwood, fish, shallow aquifer recharge, and habitat for migratory and local bird species.
The economic impact of the Challawa Dam (and the Tiga Dam further upstream) has also been negative, eventually incurring millions of dollars more in losses than were yielded in benefits. In addition, while flood control was among the intended benefits of the dam, heavy rains often cause serious flooding above the dam.

Conakry
Natural resources in Guinea’s coastal zone are crucial to local economies, which depend on their immediate environment for freshwater, fuelwood, fisheries, and agriculture. Guinea’s coastal zone is also home to one-fourth of West Africa’s mangroves, which are linked to the vitality of the terrestrial and marine ecosystems that they bridge. These resources are being exploited at an unsustainable pace due to rapid population growth which without changes in resource management practices will lead to irreversible environmental degradation.
Population in Guinea’s resource-rich coastal zone nearly tripled between 1963 and 1996. In the capital of Conakry, rural-to-urban migration, including refugees from Liberia and Sierra Leone in the 1990s, dramatically increased the population. Estimated at approximately 39 000 in the 1960s, Conakry’s population had increased to nearly two million by 2006. The growing population puts intense pressure on the surrounding woody savannahs and mangroves, which are being converted to agriculture and exploited for fuelwood.
Conakry was founded on Tombo Island at the tip of Kaloum Peninsula. Its growth since then has followed the peninsula, hemmed in on either side by mangrove forests. In the 1975 image, dense settlement has reached the airport and beyond, but natural vegetation still covered much of the area. By 2007, however, nearly all of that vegetation has been overtaken by Conakry’s rapid growth.

Congo Roads
In the dense tropical rainforest of sparsely populated northeastern Republic of the Congo, large tracts of relatively intact forest support a high concentration of biodiversity—including several large mammal species, approximately 1 700 plant species, 428 bird species, and many fish species. These forests play an important role in regulating local rainfall and climate. Tropical rain forests also absorb large amounts of carbon dioxide, a major greenhouse gas.
The 1976 image shows a large intact tract of humid tropical forest. By contrast, the 2001 image shows an extensive network of logging roads. The associated falling and removal of logs are causing considerable damage to the forest. The roads also provide access for bushmeat hunters and farmers into previously remote, intact forest. This has led to extreme over-hunting of vulnerable species including western lowland gorillas, elephants, and leopards.
Global demand for timber is expected to encourage substantial deforestation in the long term. If this deforestation triggers a landscape-scale transition from forest to woodland or savannah, the consequences for biodiversity and climate would be catastrophic.

Copperbelt
Zambia, Democratic Republic of the Congo
Large-scale copper mining began in north-central Zambia’s Copperbelt Province during the 1930s, attracting workers and turning this biologically rich savannah woodland into a heavily populated area with several large cities. Until the 1960s, the mining industry used wood from surrounding lands to generate power for the copper mines; this resulted in the clear-cutting of approximately 127 000 hectares between 1947 and 1956 and selective harvesting of trees in an area of similar size. The mining industry converted to hydroelectric power in the early 1960s, but the growing population continued to rely on wood for fuel.
Copper mining began to decline in the 1970s when oil prices rose and copper prices dropped. By the 1990s, the industry had collapsed, leaving large numbers of workers unemployed. Many of these unemployed miners turned to small-scale agriculture and charcoal production to make a living, putting additional pressure on the surrounding woodlands.
Large urban centres, open-pit mines, and areas of deforestation are already apparent in the 1972 image. These urban areas continued their rapid growth, resulting in the much larger areas of degraded and deforested woodlands visible in the 2006 image. Record copper prices in recent years have revived the area’s copper industry. Copper accounted for an average of 67 per cent of Zambia’s annual total export receipts between 2002 and 2005.

Copsa Mica
Copsa Mica is a large industrial city located in the very center of Romania and is classified as an "environmental disaster area." The environmentally damaged area covers hundreds of square kilometres of land. The main industries in Copsa Mica are non-ferrous metalworking and chemical processing plants, and their effect on the environment has been devastating. Air pollution by heavy metals is 600 times the allowed levels. To make matters worse, a lead-smelting facility emitted fumes containing sulfur dioxide, lead, cadmium, and zinc over the town and surrounding area for 50 square kilometres (19 square miles). The entire town and much of the surrounding area were covered with a blanket of black soot daily until the facilities were forced to close in 1993.

Coral Reefs of Mauritius
Over the past 50 years, the population of Mauritius has nearly doubled, to 1.2 million. It currently has the highest population density of any African country, 652 people per km2. Mauritius has also seen a dramatic growth in its economy, which has increased demands on its environment.
Coral reefs almost surround Mauritius. These are complex ecosystems, rich in biodiversity yet only able to survive in very clear, warm and nutrient-poor ocean waters. The reefs form a fringe along the island’s shores and create shallow lagoons that are extremely important to the fishing and tourism industries. The island’s population density as well as agricultural runoff, untreated sewage, changes in freshwater runoff, tourist activity, and global warming all threaten the health of the reefs.

Country Border
The border between Guatemala and Mexico runs through Mexico's Chiapas Forest and Guatemala's El Peten. In this pair of images, the border is easy to see, even without the black lines that have been overlaid on the images to show the outlines of the two countries.
The region crossed by this border was once biologically very diverse. On the Guatemalan side, it still is, as most of the El Peten remains as closed canopy forest because of lower population densities and the protected status of the Sierra de Lacondon and Laguna del Tigre National Parks. Across the border in Chiapas, however, a larger and increasing population has an obvious effect on the landscape. Between 1974 and 2000, much of the forest on the Mexican side of the border has been converted to cropland or pasture.

Dakar
Like many West African cities, Senegal’s capital city of Dakar has grown dramatically over the past several decades. Growth is expected to continue. While birth rates have begun to decline, natural growth still accounts for much of Dakar’s expansion. In addition, Dakar experienced a large rural-to-urban migration beginning in the 1960s, when Senegal suffered from declining precipitation and periods of extreme drought. By 2005, Senegal’s urban population exceeded its rural population. By 2030, two-thirds of the country’s population is expected to be urban.
Roughly half of Senegal’s urban population lives in the greater Dakar metropolitan area. Urban population growth has turned the Cap Vert Peninsula into a sprawling metropolis, where settlements reach ever-further inland and onto the prime farmland that has historically supported the city. Pikine, initially begun as a resettlement of urban slum dwellers 15 km east of Dakar, has grown to over one million people. Its location in the fertile Niayes region displaced large areas of urban and peri-urban agriculture that once provided livelihoods for a substantial portion of the population.
In the aerial photo mosaic from 1942, Dakar is concentrated at the southern tip of the peninsula, with only the airport and a few scattered roads and settlements to the north. The 2006/2007 image shows only a portion of the greater Dakar area, which currently stretches another 14 km to the city of Rufisque (not shown).

Damascus
The trend of urbanization across the Arab States region, as in other parts of the world, continues to accelerate. In the past 20 years, the level of urbanization across the region has risen from 44.1 per cent to 59.9 per cent and is expected to reach 69.8 per cent by 2020. However the rate of urbanization is not evenly distributed throughout the various countries. The urban population has actually doubled in some cities while others are experiencing more restrained growth.
Damascus, the capital city of Syria and the oldest continuously inhabited city in the world, has been experiencing extremely rapid growth over the past 33 years. The urban population of Damascus has doubled every ten years during this time, reaching a growth rate of 27 per cent in the year 2005. The number of people living in this city has increased consistently since 1972 reaching over 3.5 million in 2005. In response to the demand for land for urban development the Damascus Metro Council has expanded the regional urban growth boundary (UGB) by approximately 13,000 acres resulting in clearance of forested land, primarily for housing and road networks.
The two Landsat images show the rapid growth of Damascus between 1972 and 2005. The grey colour on these images represents area covered by urban development, the green parts show vegetation cover which has been shrinking as land is cleared for urbanization.

Damietta Promontory
The Nile Delta is built of sands carried to Egypt’s Mediterranean coast by the Nile River, primarily since the end of the last ice age. Dams along the river and entrapment of sediment in a vast network of irrigation canals have led to a dramatic decrease in the flow of water and sediment to the delta’s edge. Closing of the Aswan High Dam in 1964 shifted the balance between sedimentation and erosion in favour of erosion.
At several points along the coast, the delta is now receding. Damietta Promontory has eroded dramatically as waves and currents have stripped its sands faster than the river can replenish them (yellow arrow). While there are local areas of accretion such as the Damietta Spit (red arrow), on balance the delta is shrinking.
Prior to the construction of the Aswan High Dam, fresh water from annual floods influenced salinity and circulation patterns up to 80 km offshore from the delta. In contrast, current discharge patterns allow salt water from the Mediterranean to reach dams up to 26 km inland. Diminished freshwater and sediment delivery to the delta also affects the ecology of coastal lagoons, soil fertility, and salinisation of irrigated land. Coastal protection structures, regulation of irrigation, and increased groundwater exploitation may mitigate the delta’s decline, but the current rate of population growth threatens to outstrip these measures.

Dead Sea
For decades, heavy demands have been placed on the land-locked Dead Sea to meet the needs of growing populations in the countries that border it. Both Israel and Jordan draw water from rivers that flow into the Dead Sea, reducing the amount of water that would naturally replenish it. The amount of area devoted to evaporation ponds for producing salt has greatly expanded over the past three decades. The creation of salt works tends to accelerate evaporation, further contributing to the reduction in water level. Currently, it is estimated that the water level of the Dead Sea is dropping at a rate of about one metre (3 feet) per year.
These two images, from 1973 and 2002, reveal dramatic changes in the Dead Sea over a period of about 30 years. Declining water levels, coupled with impoundments and land reclamation projects, have greatly increased the amount of exposed arid land along the coastline. The near-complete closing off of the southern part of the Sea by dry land (2002 image) reveals the severity of water level decline.

Delhi
India occupies only two per cent of the world's total landmass. Yet it is home to 15 per cent of the world's total population. Urban growth is characteristic of most Indian cities, with that of Delhi being especially dramatic, as these satellite images from 1977 and 1999 clearly show.
In 1975, Delhi had a population of 4.4 million people or 3.3 per cent of India's entire urban population. In 2000, the city had 12.4 million inhabitants, or more than 4.5 per cent of the country's urban population. Of the world's 30 largest urban agglomerations, Delhi ranked 24th in 1975 and tenth in 2000. By 2015, Delhi's population is expected to be 20.9 million.
In these images, urban areas appear in shades of gray and purple. Growth is especially noticeable in the suburbs and areas surrounding Delhi such as Ghaziabad, Faridabad, and Gurgaon. Rapid urbanization has placed tremendous pressure on land and water resources in and around Delhi.

Dhaka
Dhaka, the capital of Bangladesh, has undergone phenomenal growth since the country gained independence in 1971. It has grown from a city of 2.5 million inhabitants to one with a population of more than ten million. This increase represents an average population growth rate of about eight per cent annually. Dhaka is one of the poorest and most densely populated cities on the planet, with 6545 people per square kilometre.
Following independence, urban areas expanded rapidly as they sought to become hubs of production and modernization. In the process, land use changed dramatically, as these images from 1977 and 2000 reveal. Dhaka is visible in the central portion of each image along the Turag River. Green areas represent forests and agricultural lands. White spots are planned areas of infrastructure. Urban areas are light purple. The 2000 image shows how, over time, lowlands and agricultural lands have been converted to urban areas where Dhaka has expanded to the north.

Diawling National Park
Prior to construction of Diama Dam across the Senegal River, land surrounding the Senegal Estuary was flooded with fresh water from late July to late September each year. During the dry season, these delta wetlands would become saltier than the ocean, as their waters were reduced by evaporation.
This yearly cycle was disrupted by the construction of the Diama Dam in 1986 (yellow arrow). Both the Diama Dam, and the Manantali Dam constructed upstream in Mali, were intended to regulate the flow of the Senegal River, generate hydroelectric power, and facilitate development of irrigated agriculture. However, irrigation in the delta has been less successful and less productive than planned; lacking proper drainage systems, the land is becoming waterlogged and saline after just a few years under irrigation.
Drought had already begun to impact the wetlands before construction of the dams in the 1980s (1979 image). Following their construction in the 1980s, fish stocks decreased and wetland vegetation was decimated. In the early 1990s, a restoration project began using controlled flooding of the delta by managed water releases. It has revived the wetlands and restored much of the lost flora and fauna to the area. The 2006 image shows the restored wetlands in and around Diawling National Park.

Djibouti City
Nearly 85 per cent of Djibouti’s population is urban, with the vast majority of urban dwellers living in the capital city, Djibouti. The city’s population grew 10-fold between 1950 and 2002 and is projected to grow another 25 per cent, to 800 000 people by 2025. The city is poor by international standards, but its relative prosperity for the area has attracted migrants from rural Djibouti and surrounding countries.
The country of Djibouti has little arable land, little rainfall, and limited possibilities for irrigation. Because of this it imports 80 per cent of its food, mostly through the port of the capital city.
Droughts during recent decades and desertification exacerbated by overgrazing have reduced the viability of pastoral life. This, along with high rural water insecurity, has helped to drive many rural residents to villages and cities—many of them settling in the capital.
Water availability in the capital is better than in rural areas, but limited supply and inadequate sanitation are problems there as well; the rapidly growing population will make the supply issue worse. Improving access to water in the rural areas is a way to address poverty and health issues in the countryside and at the same time reduce the rural-to-urban migration that is straining the capital city’s infrastructure. A recent partnership between the European Union, UNICEF, and Djibouti’s Ministry of Agriculture should bring clean, safe water to 25 000 of Djibouti’s poorest rural residents.

Doba Oil Fields
The Chad Export Project brought an investment of approximately US$3 500 million to one of the poorest countries in the world. Among the stated goals was to “provide additional resources to alleviate poverty through social sector and infrastructure development.” Concerns were voiced by non-governmental organizations at the outset; these concerns included displacement of people from traditional land and livelihoods, environmental degradation, opportunity for corruption, and inadequate capacity to enforce environmental regulations.
The project included drilling 300 oil wells in farmland surrounding Doba and construction of a 1 050-km pipeline across Cameroon to Kribi on the Atlantic Coast. Small patches of lighter green in the 1976 satellite image show agriculture already present in the area. By 2007, the intensity of agriculture had increased greatly and three clusters of oil wells, concentrated over three oil fields, can be seen. The fields of well pads show as light coloured squares at the end of access roads.
While the project has brought an influx of revenue, it remains to be seen if this translates to a better life for the people living in the vicinity of the oil fields or in Chad as a whole. World Bank documents rate the project’s performance in this regard as “moderately satisfactory.” Other reports have taken a less favourable view.

Ekati
As of 2001, the Ekati Mine was North America's only operating diamond mine. Located in the north central Northwestern Territories (NWT) of Canada, the mine yields raw diamonds from a sparsely inhabited sub-arctic region. Air transport connects mine personnel and supplies year-round, while a single winter ice road provides the only vehicular access just ten weeks per year.
Expanded mining exploration in the 1990s began a new era for this otherwise undeveloped region. Wildlife officials have collared and tracked caribou, in a herd ranging from 350 000 to half a million, to monitor their movement and behavior in proximity to the mines. Historical information about the herds comes from Dogrib and Inuit knowledge obtained from elder natives who still inhabit the NWT, and who have depended on the caribou for centuries.
These two images compare the same area, pre-mining and after mine operations have commenced. The white patch in the northwest portion of the 2000 image represents the mine and the associated infrastructure.

Escondida
Located at an elevation of 3 050 m (10 006 ft), Chile's Escondida Mine is an open-pit copper, gold, and silver mine and is also the largest copper mine in the world. Isolated in the barren and arid Atacama Desert in the country's far north, the Escondida Mine relies heavily on external well fields for the water used in its mining operations. Unlike similar mining operations, however, Escondida has a redeveloped tailings impoundment, which appears on the 1989 image as a white patch in the lower left corner. Impoundments of this type help reduce water consumption and enhance water conservation, two areas where mining activities typically fall short. The Escondida Mine also minimizes the impact of its operation on the environment by means of a 170-km-long (106 miles) underground pipeline that carries copper concentrate slurry from the mine to the port of Coloso. This underground scheme is efficient and ecologically sound, as the copper travels downhill without disrupting the environment. The 2003 image shows how the Escondida Mine has grown and expanded while at the same time continues to minimize negative impacts from its mining operations on the environment.

Everglades
These two Landsat images of southern Florida in the United States reveal some of the changes that have occurred in this region over the past 30 years. One of the most obvious is the growth of the Fort Lauderdale-Miami urban area. Urban expansion has led to the conversion of what were once farmlands to cityscapes. The city of Miami has also expanded greatly to the southwest. The advance of urban areas westward across the peninsula threatens the continued existence of the vast wetlands area known as the Everglades. The Everglades ecosystem naturally filters groundwater and helps to recharge the Biscayne Aquifer. It is also home to a remarkable collection of plants and animals for which southern Florida is famous. As urban areas encroach upon the Everglades, water resources and wildlife habitat are placed at serious risk. Protecting the Everglades to maintain its essential water filtering capacity and remarkable biodiversity is part of the mission of the Federal "Smart Growth" Task Force, which is working to better manage urban sprawl and its negative consequences.

Forest Resources
Various sources estimate Gabon’s forest cover at between 17 and 20 million hectares, comprising the majority of the Guineo-Congolese forest. Guineo-Congolese forest is a tropical rain forest ecosystem known for its high species richness and endemism. This forest is an invaluable resource to Gabon locally and is also important globally as a source of biodiversity and a carbon sink, which influences the global climate.
Over the past 40 years, the area of forest allocated to logging concessions has grown from less than 10 per cent to over 50 per cent with most of this increase occurring in the last decade. Okoume, a valuable African hardwood, accounts for over 70 per cent of Gabon’s timber harvest. It is selectively harvested by clear-cutting patches of Okoume, leaving a few trees to encourage regrowth. During the first six months of 2005, production of logs of all species in Gabon rose 4.7 per cent over the previous year.
The 2000 image shows a clear cut patch in the centre of the image at a regrowth stage. This is in contrast to the 1988 image, in which only slight disturbance of the forest cover is visible. The least densely populated country in Central Africa, Gabon has less pressure than many of its neighbours to convert forests to agricultural land. With good forest management practices, the immense value of Gabon’s Guineo-Congolese forest can be sustainably utilized for many generations.

Freetown
Freetown, Sierra Leone’s capital city, shares a peninsula with the Western Area Forest Reserve—a small remnant of the Guinean Forests that historically stretched from Guinea to Cameroon. The century-old reserve covers a chain of forested hills that are home to approximately 300 species of birds and a small population of chimpanzees.
Intense population growth began in Freetown in the 1970s. However, a buffer of forested land remained between the Reserve and the edge of the city. By the mid-1980s, however, the growing city had expanded into the buffer zone and much closer to Reserve borders (1986 image). Between 1991 and 2002, as many as one million people fled to Freetown as a result of war in Sierra Leone. Many of these refugees moved into the hills of the Reserve, where they relied on its resources to survive. Deforestation and land degradation of these valuable protected lands was the result. By 2003, the border of the Reserve had been breached in many places (2003 image), with urban populations encroaching from several directions.
The Reserve is now recognized as vital, not only to the biodiversity and natural systems it supports, but to the people of Freetown as well. The forest is crucial for recharging Freetown’s reservoirs, which are already struggling to meet the city’s water needs.

Fynbos
The Cape Floristic Region is a Mediterranean-type ecosystem unique to the southwest tip of Africa. It has the greatest concentration of plant species in the world outside of tropical ecosystems, with 6 210 of its 9 000 species occurring nowhere else in the world. Although the region is relatively small, its plant biodiversity is the richest per unit area on Earth, prompting its designation as a biodiversity hotspot.
The characteristic and most widespread type of vegetation in the Cape Floristic Region is fynbos, an Afrikaans word that translates as “fine bush.” Covering some 46 000 square kilometres, fynbos is a shrubland comprising hard-leafed, evergreen, fire-adapted shrubs. Fynbos covers half of the surface area and accounts for 80 per cent of the plant varieties of the Cape Floristic Region.
The 1978 image shows large, relatively intact areas of native fynbos vegetation. Over subsequent decades, however, large tracts of fynbos have been cleared for agriculture or lost to urban expansion around Cape Town. The 2007 image shows how roads, urban development, and agriculture have overtaken much of the area.
Fynbos areas are also threatened by invasive alien species, particularly wattle and acacia species from Australia, as well as pine plantations. Many fynbos species have gone extinct, and more than 1 000 are endangered. Their conservation is a priority, and reserves have been established in many areas.

Gabcikovo
The Gabcikovo-Nagymoros hydraulic project on the Danube River was started in order to generate electric power, create an inland waterway, help manage water supplies and aid in the region's economic development. The river was to be dammed and its water diverted into a canal. Four decades after it was initiated, the Cunovo Dam began operation in Slovakia in October 1992. The dam diverted 80 to 90 per cent of Danube River water down a diversion canal to support a hydroelectric power station.
This pair of images from 1973 and 2000 reveal the striking changes the massive re-channeling of river water has brought to the region. The dam altered the hydraulic regime of the Danube River valley from a natural waterway to a controlled patchwork of channels and islands. The diversion of water by the dam brought an end to the natural, beneficial flooding that added moisture and nutrients to the soil. It also reduced the ability of wetlands and marshes to filter surface water and trap sediments. Consequently, water quality and soil nutrients levels in the region have declined. Generation of electricity has come with significant environmental cost.

Ghana’s Tropical Forest Zone
The fragmented tropical forest of southwestern Ghana creates a fascinating pattern from space. The dark green patches are reserves set aside early in the 20th century; they are the only significant blocks of forest remaining in the country. Recognizing this priceless ecological heritage, the Ghanaian government has developed policies for sustainable forest management.
In spite of the enormous ecological benefits of the forest and the government’s effort to sustainably manage the reserves, shifting cultivation, uncontrolled logging, surface mining, charcoal production, and increasing population place enormous pressure on these remnants of Ghana’s tropical forests. In the 1973 image the vegetation inside and outside the protected areas appears green and robust. In the 2002/2003, dramatic change is apparent; some of the northern reserves have been decimated and the northern edge of the forest zone has moved south.
Recently, mines have been permitted within some of Ghana’s forest reserves. On the advice of the International Monetary Fund (IMF), Ghana relaxed mining and logging regulations and nurtured investment by the mining and forestry industries through generous incentives during the 1980s and 1990s. Mines like the one within the Afao Hills Forest Reserve (double click layer) pose a serious threat to Ghana’s remaining forests.

Gishwati Forest
Gishwati Forest Reserve in northwestern Rwanda is one of the most severely deforested areas in the country. Exploitation of the forests for commercial products such as charcoal, timber, medicine, and food has been the main driver of this deforestation. The 1978 satellite image shows the Gishwati Forest Reserve as a dark-green carpet of dense forest nearly covering the entire protected area. The 2006 image shows that most of the forest has been cleared; the dark-green areas have been replaced by patches of pink and light green where the vegetation has been largely removed. Only a fraction of the forest that was intact in 1978 remains; what is left is in degraded condition.
On a positive note, reforestation efforts in parts of the region, using agroforestry techniques such as radical terracing, progressive terracing, and live mulches, are currently being researched and implemented. Seedlings of species such as Calliandra calothyrsus and Leucaena diversifolia are being planted in several provinces of the country with collaboration from stakeholders and the local community. If such efforts continue and are successful, the Gishwati Forest Reserve may experience considerable regeneration within the next five to ten years.

Great Man-made River Project
In the 1950s, oil exploration in Libyan Arab Jamahiriya turned up another resource beneath the scorching sands: the Nubian Sandstone Aquifer System. Radiocarbon analysis showed that some of the water in the aquifer system was 40 000 years old. Tapping the aquifers was chosen as the most cost-effective option for meeting the country’s water needs.
In 1993, Phase I of the Great Man-made River (GMMR) Project brought water from eastern well-fields at Sarir and Tazerbo to Benghazi (not shown). In 1996, Phase II brought water from well-fields at Jebel Hassouna to Tripoli (not shown). Phase III is still under construction. The project’s largest reservoir, known as the Grand Omar Mukhtar, is located at Suluq (double click on the Suluq tabs in the table of contents).
When fully operational, the GMMR will pump 3.6 million cubic metres of the Nubian Aquifer water per day. Water from the aquifer is used to support extensive centre-pivot irrigation agriculture at Al Kufra.
At current extraction rates the Nubian Sandstone Aquifer System is not likely to be depleted for a thousand years. Nevertheless, it is shared among four African nations: Libyan Arab Jamahiriya, Chad, Sudan, and Egypt. The concern of environmentalists is that eventually people will drain the aquifer faster than nature can renew it. The International Atomic Energy Agency is trying to bring the four countries together to plan rational shared use of the water.

Great Man-made River Project, Suluq
In the 1950s, oil exploration in Libyan Arab Jamahiriya turned up another resource beneath the scorching sands: the Nubian Sandstone Aquifer System. Radiocarbon analysis showed that some of the water in the aquifer system was 40 000 years old. Tapping the aquifers was chosen as the most cost-effective option for meeting the country’s water needs.
In 1993, Phase I of the Great Man-made River (GMMR) Project brought water from eastern well-fields at Sarir and Tazerbo to Benghazi (not shown). In 1996, Phase II brought water from well-fields at Jebel Hassouna to Tripoli (not shown). Phase III is still under construction. The project’s largest reservoir, known as the Grand Omar Mukhtar, is located at Suluq (yellow arrows on 2006 image).
When fully operational, the GMMR will pump 3.6 million cubic metres of the Nubian Aquifer water per day. Water from the aquifer is used to support extensive centre-pivot irrigation agriculture at Al Kufra (double click on the Al Kufra tabs in the table of content).
At current extraction rates the Nubian Sandstone Aquifer System is not likely to be depleted for a thousand years. Nevertheless, it is shared among four African nations: Libyan Arab Jamahiriya, Chad, Sudan, and Egypt. The concern of environmentalists is that eventually people will drain the aquifer faster than nature can renew it. The International Atomic Energy Agency is trying to bring the four countries together to plan rational shared use of the water.

Green River
The Upper Green River Basin (UGRB) is western Wyoming's sagebrush steppe, a landscape punctuated by ribbons of wildlife habitat, stunning vistas, and important cultural sites. The basin serves as the winter home of large herds of pronghorn antelope and mule deer, which migrate into the area from the highlands of Grand Teton and Yellowstone National Parks.
With its extraordinary reserves of oil and natural gas, the UGRB has become a focal point for the oil and gas industry. Over three thousand wells (black dots in the center of the 2004 image) have been approved in the UGRB and development is occurring at a rapid rate - one that exceeds the Bureau of Land Management's "reasonably foreseeable development" plan by more than 300 per cent. The environmental impacts of this rapidly escalating oil and natural gas development are not clear, and conservationists are pressing for measures that will help safeguard the region's wildlife, air and water resources.

Guinea Refugee Camps
Between Sierra Leone and Liberia, there is a small strip of land belonging to Guinea known as the "Parrot's Beak." As civil wars raged in Sierra Leone and Liberia, hundreds of thousands of refugees have fled to relative safety in Guinea, many of them settling in the Parrot's Beak. The United Nations High Commissioner for Refugees (UNHCR) estimates that the refugee population constitutes up to 80 per cent of the local population there (UNEP 2000).
The 1974 image of the Parrot's Beak in Guinea shows the surrounding territory of Liberia and Sierra Leone. Scattered throughout the deep green forest of the Parrot's Beak region are small flecks of light green, where compounds of villages with surrounding agricultural plots are located. Several dark spots in the upper left of the image are most likely burn scars.
The 2002 image shows the Parrot's Beak region clearly defined by its light green color surrounded by darker green forest. The light green color is the result of deforestation in the "safe area" where refugees have set up camp. Many of the refugees integrated into local villages, created their own family plots, and expanded the zones of converted forest area until they all merged into the larger defined area. In the upper part of the 2002 image the forest devastation is especially obvious, as areas that were green in the 1974 image now appear gray. Logging interests also moved into the higher elevations of this region, expanding the deforested zone visible in the upper left corner of the image.
Overall impoverishment of the environment of the Parrot's Beak is directly related to the rapidly increasing population in the area, mainly due to immigration, and a growth rate of about three per cent among the indigenous population. Natural resources are being exploited to create more arable land for crops, wood for charcoal, firewood and construction materials, and commercial logging for revenue.

Gulf of Fonseca
Honduras is second only to Ecuador in the production and export of cultured shrimp from Latin America. Vast areas of the delta formed by the Choluteca and the Estero Real Rivers have been converted into farms for the cultivation of shrimp. The rapid growth of shrimp aquaculture in Honduras has caused both environmental and social problems. Shrimp farmers are depriving fishers, farmers and others of access to mangroves, estuaries and seasonal lagoons; destroying mangrove ecosystems, altering the hydrology of the region, destroying the habitats of other flora and fauna and precipitating declines in biodiversity; contributing to degraded water quality; and exacerbating the decline in Gulf fisheries through the indiscriminate capture of other species caught with the shrimp post larvae that are used to stock ponds. These two images provide a visual comparison of the increase in coverage by shrimp farms in the Gulf of Fonseca over time. The shrimp ponds appear as blue rectangles near the water line scattered across the delta in the 1999 image. It is evident from the images that between 1987 and 1999, a period of about 12 years, the total area under shrimp farming has increased tremendously.

Gulf of Guayaquil
Guayaquil is Ecuador's largest city and primary sea port. It is located on the Guayas river, which empties into the huge Gulf of Guayaquil along the country's southern coastline. Throughout the Gulf, mangroves have been steadily converted to shrimp aquaculture ponds for producing farmed shrimp. In a 15-year period, coastal area developed for shrimp aquaculture grew by approximately 30 per cent, from 90 000 hectares in 1984 to 118 000 hectares in 2000 (CLIRSEN 2000). Roughly 70 per cent of Ecuador's shrimp farming activities are located in the Gulf of Guayaquil. In this pair of satellite images, the loss of mangroves and growth of the aquaculture industry can be seen along the coast and in the altered dendritic patterns (branching like a tree) of coastal waterways, especially those on the large island of Puna. Mangroves provide fish breeding grounds and wildlife habitat, act as natural barriers against storm surge, and filter groundwater. Converting mangroves to aquaculture ponds has wide-reaching environmental implications.

Harbel Rubber Plantation
Built in the 1920s and 1930s, the Harbel rubber plantation just north of Monrovia, Liberia, is the largest in the world. This large monoculture plantation has created a host of environmental problems, including loss of biodiversity and the release of chemical waste into surface waters. Plantation workers are also exposed to compounds and chemicals that are internationally recognized as toxic and environmentally damaging. These two images show that the extent of the Harbel rubber plantation which has expanded just slightly in 30 years.
The change in colour of most of the plantation’s vegetation may be the result of seasonal variations—rubber trees drop their leaves at least once per year—or the age of the trees in the later image. Mature stands have more shadows and allow less of the leafy understory vegetation to show through than younger trees.
Most of the trees on Liberia’s rubber plantations are nearing the end of their productive lifespan. This has brought the country’s rubber industry to the brink of collapse. A new extension to the lease arrangement between Harbel’s owners and the Liberian government was signed in 2005 which, according to the company, will allow for replanting to begin. However, it will likely take many years for the older trees to be replaced.

Hassi R'Mel Oil Fields
In 2006, oil and natural gas exports made up 98 per cent of Algeria’s total exports. A major portion of these fuels came from the Hassi R’Mel gas fields, located about 550 km south of Algiers. The fields were discovered in 1956; initial production started in 1961, and it has since become one of the world’s largest gas fields.
These two satellite images show the dramatic development of this area in the last three decades. In the 1972 image, changes to the landscape are minor compared to the 2006 image, which reveals vastly expanded infrastructure, mainly related to the gas fields. Turn off these two images and zoom in on the Google Earth surface to see detail of the developed area around Hassi R' Mel.
In addition to gas production, Algeria began building a hybrid gas and solar power generating facility at Hassi R’Mel in July 2007. It will produce 150 megawatts of electricity, with 25 megawatts coming from 180 000 m2 of parabolic reflectors. The first of its kind, this facility is expected to be operating by 2010. By 2020 Algeria hopes to be exporting 6 000 megawatts of power to Europe—roughly the equivalent of 10 per cent of Germany’s current consumption.

Helheim Glacier
After years of moving at a relatively stable speed, Helheim Glacier in southern Greenland has dramatically accelerated. According to a University of California-Santa Cruz study, the glacier's peak rate of flow has increased from 8 km per year in 2000 to 11 km per year in 2005. In addition to flowing more rapidly the glacier thinned by 40 meters between 2001 and 2003. The calving front of the glacier − the area where the ice breaks away and falls into the ocean − has retreated by approximately 5 km. These images show the retreat of Helheim Glacier's calving front between September of 1986 (Landsat) and July of 2006 (ASTER).
According to one of the authors of the study, the likely underlying cause of these changes is higher air and water temperatures in the area of Southern Greenland. However, the study also identifies a relationship between the retreating front of outlet glaciers such as Helheim and an increase in the rate of flow (as the front of the glacier retreats it offers less resistance to the glacier's movement). The dynamic interactions of temperature, glacier flow rates, and ice thickness complicate the modeling of future changes in the Greenland ice sheet. These processes are likely to continue to accelerate under prevailing climate change scenarios.
The overall Greenland ice sheet contains approximately 10 percent of the world's freshwater and is up to two miles thick. If the entire Greenland ice sheet were to melt it would raise sea level by 20 feet. Howat believes that if the processes which are accelerating the thinning and retreat of Helheim Glacier are occurring at other glaciers throughout Greenland, the time it will take for the Greenland ice sheet to disappear could be cut in half.

Huambo Province
While Huambo province has been referred to as the “breadbasket of Angola,” its soils in reality are not ideal for agriculture. Many years of intensive cash crop agriculture on these marginal soils dating back to the 1920/1930s has further diminished their agricultural capacity.
During Angola’s civil war (1976-2002) many people who could not leave the region moved to the safer zones along the Benguela Railways corridor between Huambo and Caála. In the 2006 image this human activity shows as the lighter colours and loss of green throughout the centre of the image, particularly surrounding the two cities and the rail line between them. This concentration of settlement and agriculture with minimal inputs further degraded soils in these areas.
Deforestation has also been found to be an important cause of land degradation and relocation in Huambo province. The loss of several forested areas, including some forest plantations, can be seen between the 1973 and 2006 images, where patches of dense green have been replaced by more reflective farmland and dense settlement (yellow arrows). At the end of the war, many of those returning to Huambo province found their land would no longer support them and were again displaced. In addition, returning refugees found that destruction of infrastructure, limited availability of inputs, and limited seed stock further reduced their prospects.

Huang He Delta
The Huang He (Yellow River) is the muddiest river on Earth and is China's second longest river, running 5 475 km (3 395 miles) from eastern Tibet to the Bohai Sea. The Huang He's yellow color is caused by its tremendous load of sediment, composed primarily of mica, quartz, and feldspar particles. The sediment enters the water as the river carves its way through the highly erodable loess plateau in north-central China (Loessial soil is called huang tu, or "yellow earth," in Chinese). Centuries of sediment deposition and dike building along the river's course has caused it to flow above the surrounding farmland in some places, making flooding a critically dangerous problem. Where the Huang He flows into the ocean, sediments are continuously deposited in the river delta, where they gradually build up over time. Between 1979 and 2000 - as these satellite images show - the delta of the Huang He river expanded dramatically. Several hundred square kilometres of newly formed land were added to China's coast during this period.

Hubbard Glacier
Hubbard Glacier, located at Wrangell-St. Elias National Park near Yakutat, Alaska, is the largest calving glacier in North America. It is currently increasing in total mass and advancing across the entrance of 56-km-long (35-mile-long) Russell Fjord. These images show the potential environmental disruption that a fast glacial flow is capable of producing.
In 1986, the Hubbard Glacier blocked the Russell Fjord, endangering seals and porpoises by producing freshwater runoff that reduced the salinity of that body of water. Rising water levels also became a concern. By the time the ice dam eventually broke later that year, the water level of Russell Fjord had risen by 25 m (82 ft).
In late May or early June, 2002, Hubbard Glacier again pushed forward, blocking the seaward entrance to Russell Fiord and began to restrict the tidal exchange between Disenchantment Bay and Russell Fiord. By late July, the dam completely sealed off the lake. At 3 a.m. on August 14th, Russell Lake burst through the dam again becoming Russell Fjord. A one-hour peak discharge of 54,000 cubic meters of water per second (1.9 million cubic feet per second) is the second largest measured glacial lake outburst worldwide in historical times, exceeded only by the 1986 outburst from Russell Lake, which was about 105,000 cubic meters per second (3.7 million cubic feet per second). In comparison, the August 14 peak discharge was about 30 percent greater than the peak historic flow on the Mississippi River at Baton Rouge, La.

Iguazú
Iguazú National Park, located in Argentina near its borders with Brazil and Paraguay, contains remnants of the highly endangered Paranaense Rain Forest. Isolated from other rain forests by natural barriers, the Paranaense developed a distinct and highly diverse ecosystem with thousands of species of mammals, birds, reptiles, and amphibians unique to the area. The famous Iguazú Falls are located within the boundaries of the National Park and are shared by Argentina and Brazil.
Between 1973 and 2003, dramatic changes to the landscape occurred in this region. In 1973 the forested area spread across the borders of the three nations. By 2003, however, large areas of the forest in Paraguay and Brazil, and smaller amounts in Argentina, had been converted to other forms of land cover, creating a mosaic of differently colored land use areas. Note the variation in land cover patterns among the different countries - reflections of different land use polices
and practices.

IJsselmeer
The Zuiderzee is a large body of water along Holland's northeastern coast. Between 1927 and 1932, a 30-km (19 miles) dam, known as the Afsluitdijk, was built across the Zuiderzee, separating it into the outer Waddenzee, which is open to the North Sea, and the inner IJsselmeer (Lake IJssel) where areas of reclaimed land - called polders - are used for agriculture and as villages. Dikes built since that time created additional polders that were drained using pumps and, at one time, wind mills. These images, from 1973, and 2004, show the transformation of polders into useable farming land. The 1973 image shows a partially completed dike that, when completed allowed for the creation of the southernmost polder visible in the 1973 image. At that time, draining of the land had been completed and soil cultivation began. By 2004, this area of reclaimed land was covered with farms. The area of lighter blue water visible in the left of the 1973 and 2004 images is the Markermeer - a polder that was created but not drained. It forms a freshwater reservoir that acts as a buffer against floodwaters.

Isahaya Bay
Land reclamation began in Japan's Isahaya Bay in 1989. It separated approximately 3000 hectares of tidal flats from the Ariake Sea, and turned what was Japan's largest area of tidal lands into farmland. These satellite images show the progression of the project. In the 2001 image, the straight line of a 7-km (4 mile) sea wall is visibly separating areas of light- and dark-colored water. Behind the sea wall, the dessication of tidal flats can be seen as water is slowly drained away. In the 2003 image, that area has been fully reclaimed from the sea. The Isahaya Bay Reclamation project has been fraught with controversy. Environmental groups have criticized the project for its destruction of wetland habitat. The Isahaya Bay area is known for its production of nori (seaweed), and local farmers have complained that the reclamation project has negatively impacted the quality and abundance of nori cultivation in the bay. The Isahaya project prompted the formation of the Japan Wetlands Action Network, a group of grassroots and national conservation organizations who are protesting the project and recommending that the sea wall gates be opened in order to restore ecological balance.

Itampolo
Madagascar is the world's fourth largest island and has been described as an "alternative world" or a "world apart" because of its unique and rare plant and animal species. Madagascar was once almost completely forested. But the practice of burning the forest to clear land for dry rice cultivation has over time denuded most of the landscape, particularly in the central highlands (tan colour in the 2001 image). Coffee production, grazing, gathering fuelwood, logging, cattle ranching, mining and other activities also have contributed to deforestation and land degradation. This set of satellite images shows a narrow coastal plain near the Linta River of southwestern Madagascar. Between 1973 and 2001, the forests in this area have all but disappeared. Remarkably, numerous endemic species still remain in scattered forest remnants.

Jebel Marra Foothills
The Jebel Marra Massif is a region of high, jagged peaks and fertile valleys in western Sudan. The southern foothills of the Jebel Marra receive an average of 600 to 800 mm of precipitation annually, just above the minimum needed to support rain-fed agriculture. Crops include sorghum, millet, groundnuts, and cowpeas that are raised along watercourses and adjacent areas. Pastoralists seasonally graze their cattle on the natural vegetation in the region; the number of grazing herds has increased in recent decades as droughts have made water and pasture scarce further north.
Population growth , especially in the latter half of the 20th century, coupled with an influx of refugees from drought and conflict in Northern Darfur have put increasing pressure on this fragile ecosystem. Human activities have greatly altered the natural open-savannah woodlands.
The 1972 image shows substantial tree cover across much of the lower left half of the image. The 2006 image shows the degree to which vegetation has been reduced, particularly in the less hilly areas and away from croplands concentrated along the watercourses. The loss of trees and shrubs in this fragile environment is leading to land degradation and reduced capacity to support the area’s ever-increasing population.

Juba River Flooding
Towards the end of 2006, the Horn of Africa received heavy rains generally believed to have been the consequence of an El Niño weather pattern over the Pacific Ocean. By late November and early December, flooding had displaced roughly half a million people, destroyed crops and villages, and caused outbreaks of disease. The severity of the floods made relief efforts extremely difficult. By December these floods were the worst Somalia had seen in ten years. In March 2007, predictions of above-normal spring rains in the upper reaches of the Juba River watershed threatened to cause more flooding.
The September 2006 and December 2006 images show a portion of the Juba River before and after the rains came, respectively. Flooded areas appear as dark-green to black.
In spite of profound negative impacts of the flooding in the Juba River region, two consecutive seasons of heavy precipitation may have benefited cereal grain production and improved pastoral conditions in the region, substantially reducing the need for humanitarian assistance.

Jwaneng
Botswana is the world's leading producer of gem quality diamonds. The diamond industry accounts for 70 per cent of export earnings within the country. Diamond production in Botswana is dominated by Debswana − the world's leading producer of gem diamonds − a joint venture company owned by De Beers Investments (50 per cent) and the Government of Botswana (50 per cent). The Jwaneng diamond mine is located in south-central Botswana about 170 km (110 miles) west of the city of Gaborone, in the Naledi River Valley of the Kalahari.
Jwaneng is an open pit mine, dug over three kimberlite pipes that converge near the surface covering 520 000 square metres at ground level. The mine operates medium- to very large-scale seven−day week operations and boasts a very high extraction rate, producing 9.3 million tons of kimberlite ore per year at a ratio of 1.25 carats of diamond per ton. The mine produces 9.3 million tons per year of ore and an additional 37 million tons per year of waste rock. The high rate of diamond extraction, combined with high quality diamonds fetching excellent per weight prices, make the Jwaneng diamond mine the richest diamond mine in the world by value of recovered diamonds.
The image of 1973 shows no signs of mining activity, however, by the time of the 2006 image the large diamond mine is over 8 km from end to end.
Apart from being the richest diamond mine, the Jwaneng mine owns and operates a local hospital and airport and has maintained a 5 star NOSA safety rating since 1986. With over 2100 employees, the Jwaneng mine is also the first Botswana company to receive ISO 14001 certification in 2000, for environmental compliance. The mine has won multiple national and international safety awards since its inception.

Kafue Wetlands
In southern Zambia, the Kafue River crosses a broad floodplain roughly 255 km long. Before the Itezhi-tezhi Dam was built on the river in 1978, flooding beginning in the month of December would cover much of the plain well into the dry season. Although the dam was built to allow the release of sufficient water to cause seasonal flooding, this mimicking of the natural floods has in general not been practised.
The Kafue Flats floodplain provides important habitat for rare and endemic species, including the Kafue lechwe (antelope) and wattled crane, and supports local livelihoods, especially cattle-raising and fishing. Limited seasonal flooding following the construction of the dam has been linked to a decline in fish production and in the Kafue lechwe population. The number of lechwe fell from around 90 000 before the dam was built to around 37 000 in 1998. In 2004, a partnership between World Wildlife Fund, the Zambian Ministry of Energy and Water Development, and the Zambian Electricity Supply Company put new rules in place for water releases from the dam to mimic natural flooding patterns more successfully.
The 1970s image shows Kafue Flats in the dry season, with water levels retreating. The Kafue Gorge Dam can be seen in the lower right corner of the image. Itezhi-tezhi Dam was built a few years later to provide more storage capacity for electricity generation at the Kafue Gorge Dam. The 2007 image shows the Kafue Flats during wet season floods, helped for the first time by the release of adequate water from the Itezhi-tezhi Dam.

Kangerdlugssuaq Glacier
Kangerdlugssuaq, the largest outlet glacier on Greenland’s east coast, is one of 12 fast flowing outlet glaciers that discharge ice into the surrounding oceans. Its rate of flow more than doubled between 2000 and 2005 reaching a speed of 14 km per year or 1.6 meters per hour. It has since slowed. During this same period mean summer temperature at coastal weather stations along southeastern Greenland increased 1.1° C. While the mechanisms controlling the rate of flow are complex and not fully understood, there is a general consensus that warming temperatures are driving the increased rates of discharge.
The fronts of glaciers throughout southeast Greenland also receded rapidly during this same time period; an average retreat of 24 m/yr increasing to an average of 175 m/yr. Kangerdlugssuaq Glacier, which had been retreating 25 to 100 meters per year in the period between 1992 and 2000, retreated more than 4 km between April 2004 and April 2005.
The loss of the Greenland Ice sheet is a major factor in projecting the sea level rise which might result from global warming. Loss of the entire sheet would raise global sea level an estimated 7 meters. If melting were the only mechanism through which Greenland was losing ice mass, this could take 1000s of years. The acceleration of Greenland’s glaciers raises concerns that the global sea level may rise more rapidly under global warming scenarios than had previously been estimated.
your legs.

Kantang
These mangroves, in the Trang River Estuary in Thailand, are under threat from upstream discharge of wastewater, industrial facilities and unsustainable aqua culture practices - particularly commercial shrimp farming. From 1975 to 1993, it is estimated that about half of Thailand's mangroves along its 2,560 kilometer coastline have been lost. The larger area of the Had Chao Mai Marine National Park, the Ta Libong Island Non-Hunting Area and the Trang River Estuaries has been designated a Ramsar Wetland Site and supports over 200 bird species including many "critically endangered" , "endangered", "vulnerable" and "threatened" species.
In these two Landsat images shrimp farms appear as bluish purple squares located near the streams. Between the earlier image acquired in January, 1990 and the later image acquired approximately 11 years later there is an explosion in shrimp farming throughout the estuary.
Mangrove ecosystems are the interface between the marine and terrestrial ecosystems and provide important services to both. The fallen leaves and branches contribute important nutrients, making healthy nursery areas for the breeding of many marine species and in turn creating healthy fisheries. They are also prime habitat for migratory birds, amphibians and terrestrial species.
The international market for shrimp will likely continue to drive the development of commercial shrimp farming. Protection of areas such as Kantang will become increasingly important to preserving the dwindling areas of viable mangrove forest throughout the tropics.

Kara-Bogaz-Gol
The Kara-Bogaz-Gol (KBG) is a large, shallow lagoon of the Caspian Sea, normally about 18 200 km2 (7,000 square miles) and just a few meters deep. The Caspian Sea's changing water level has been a concern for almost a century, but especially since the 1970s. Since the KBG's water flows in from the Caspian, the Caspian's fluctuations have affected the KBG dramatically.
In 1980, in response to the rapidly dropping sea level, a dam was constructed to prevent water from flowing into the shallow and restricted Kara-Bogaz-Gol basin, resulting in the drying up of the lagoon. The dam was intended to prevent Caspian Sea water from flowing into the Kara-Bogaz-Gol, which the builders of the dam believed was acting as an evaporation pond and contributing to the lowered water levels. The dam created environmental problems and was demolished in 1992. Credit: NASA Johnson Space Center

Kavango Region
The Kavango Region, located in Namibia’s relatively wet northeastern corner, is part of the eight per cent of the country that receives about 500 mm of rain per year—the minimum considered necessary for non-irrigated agriculture. However, because this rainfall is irregular and evaporation rates are high, it is often inadequate for successful farming. Many of the soils in this area, with low nutrients or high salinity, are also marginal for farming. Nevertheless, roughly 55 per cent of the region is used for subsistence agriculture with pearl millet being the predominant crop.
Savannah woodlands are the natural vegetation in the sandy soils surrounding Rundu, near the Okavango River. Many of the woodlands along the river have long been cleared for agriculture. More recently, government-dug wells have enabled settlement and farming further from the river, leading to further deforestation, particularly in the dry river beds (omurambas), where the soils are better for farming.
The Namibian government considers this area an important focus of economic activity and supports many water and agricultural projects. Along with rapid development, the population of Rundu is growing at a staggering pace—911 per cent between 1981 and 1991. These images, from 1973 and 2007, show the dramatic increase in the land area cleared for agriculture (light yellow patches) around Rundu and elsewhere along the river.

Kibira Forest
Uncontrolled cutting of trees for fuelwood coupled with land clearing for agriculture and grazing in Burundi has resulted in profound deforestation—as much as 47 per cent of the country’s forest cover has disappeared since 1990. Along the mountains dividing the Congo and Nile River Basins is Kibira Forest, Burundi’s only montane rain forest. This 40 000-hectare forest and national park is home to 644 plant species including the threatened African mahogany species, Entandrophragma excelsum, as well as 98 mammal and roughly 200 bird species. Kibira is also the source for 75 per cent of the water driving the country’s largest hydroelectric dam.
The 2004/2006 image shows Kibira Forest as an island of green in a largely deforested landscape. The image shows how agriculture—large and small—is closing in on the forest boundaries. While the forest is a national park, it faces continued pressure from legal and illegal cutting of trees, cutting of bamboo, fire, poaching, grazing, and agriculture. Light green patches (yellow arrows) show evidence of disturbance where the mature forest has most likely been lost to fire or tree-cutting. Limited legal forestry is allowed in the park; however inadequate capacity to enforce policy has led to considerable illegal logging and clearing for farms.

Kisangani
Kisangani, in the Democratic Republic of the Congo, is located along the Congo River in the northwestern part of the country. It is a city of roughly a half million people.
In these images, most of the region around Kisangani is a rich green colour, indicative of dense forest cover. However, directly around the city is a light green zone -evidence of deforestation and conversion of the land to other uses. In the second image, taken in 2001, the cleared area around the city has grown and become consolidated; it has also spread along the rivers and the roads. Much of the deforestation is attributed to the influx of refugees into the country. Even the denser parts of the forest, once thought to be impenetrable, show signs of deforestation.

Knife River Delta
Snow geese migrate each spring to the shores of Hudson Bay, Canada, to breed and to raise their chicks. Over the past few decades, the numbers of geese descending upon the Bay's Knife River delta area have increased substantially. Their impact on coastal vegetation can clearly be seen in this pair of satellite images. In the image on the right, notice how the vegetation (green) has receded from the shoreline north of the delta. Snow geese have overgrazed this area and turned the shoreline into an enormous mudflat. Having denuded the shoreline of vegetation, the geese have also moved inland in search of food on the tundra, where overgrazed soil quickly becomes barren and develops a crust of salt due to evaporation. The salty layer prevents the regrowth of plants, and ultimately leads to erosion. Some researchers have suggested lifting restrictions on the hunting of snow geese in an attempt to reduce their numbers and control the overgrazing problem. Others believe such measures are "too little, too late."

Kuala Lumpur
With a population over 1.4 million (and approximately twice that number in the greater metropolitan area), Kuala Lumpur is the largest city in Malaysia and is growing rapidly. Its sprawl is now encroaching on the mangrove forests at the coastline (approximately 35 kilometers to the west of the city centre).
These Landsat satellite images from 1974 through 2005 show the gradual spread of development and the loss of mangrove forest that has resulted. By 1975, many areas of mangrove had already been converted to agriculture. As thirty years pass, the agricultural areas expanded and more mangroves were converted to farms. At the same time, these images show the agricultural areas being converted to industrial and urban land use. Elsewhere along the Malaysian coastline, mangroves are rapidly being converted to commercial shrimp farms. Forestry Department statistics show that peninsular Malaysia had 85,800 hectares (214,500 acres) of mangrove swamp forests in 2003, down from 86,497 hectares just one year earlier.
Mangroves are biologically diverse and highly productive ecosystems that offer valuable habitats to a wide variety of both marine and terrestrial species. They are being lost at an alarming rate throughout the tropics. Protection of these areas may be needed to ensure the survival of this valuable natural resource. Nevertheless, many countries, including Malaysia are converting large areas of mangrove forest for agriculture and aquaculture. Governments will face intense economic pressure to continue converting mangroves to land use which can provide short term economic gains. Sustainable development will require tradeoffs between this short term gain and long term viability of the environment.

Lake Alaotra
Lake Alaotra is a shallow, reed-fringed lake that lies in a tectonic basin 40 km (25 miles) long and 9.5 km (6 miles) wide. The image from April 2001 shows extensive flooding of the lake, especially along its western and southern shores. Heavy rains, unusual for the time of year, caused severe flooding across Madagascar, destroying an estimated ten per cent of the region's rice crop. This pair of satellite images shows flooding over a wide area, including Lake Alaotra. In the images, vegetation shows as bright green, water as shades of blue, and clouds as light blue. Intensive rice irrigation occurs at the western part of the lake.

Lake Alemaya
Lake Alemaya in the Ethiopian Highlands has historically provided the surrounding area with water for domestic use, irrigation, and livestock and has served as a local fishery. As recently as the mid-1980s its maximum depth was around eight metres and it covered 4.72 km2. Since then Alemaya’s water level and surface area have declined considerably, as is evident in the changes between these images. In recent years, low water levels have interrupted the water supply in Harar, a nearby town of over 100 000.
Increasing irrigation and domestic water use change in the local climate, and changes in the surrounding land cover are believed to be the causes of Alemaya’s demise. Agriculture expanded dramatically starting in the mid-1970s due to improved infrastructure, increased population, and changes in government policies toward production and marketing. Among the crops grown is khat, a psychoactive leaf consumed heavily in northeastern Africa. Khat has become an exported cash crop in recent decades and irrigation has increased as a result. In addition, siltation caused by the deforestation of the Alemaya watershed has reduced the capacity of the shallow lake. A trend of warmer temperatures since the mid-1980s may also have increased the rate of evaporation from the lake.

Lake Balkhash
Located in Kazakhstan, Central Asia, Lake Balkhash is replenished from the Ili River catchment area, most of which is located in northwestern China. The lake is a very important resource for the surrounding population. Water from the lake and its tributary rivers is used for irrigation as well as municipal and industrial purposes, including supplying the water needs of the Balkhash Copper Melting Plant.
While fish from the lake are an important food source, artificially low water prices have encouraged excessive use and waste of lake water. The United Nations has warned that Lake Balkhash, which is the second largest lake in Central Asia after the Aral Sea, could dry up if current trends are not reversed.
These two satellite images reveal an alarming drop in the lake's water levels in just over twenty years. Smaller, neighboring lakes, to the southeast of Balkhash, have become detached from the main water body; they have dramatically decreased in size and appear to be drying up.

Lake Cahora Basa
The Zambezi River drains an area of roughly 1.5 million km2 from Angola to Mozambique. In 1974, the Cahora Bassa Dam was completed about 300 km upstream from where the Zambezi River empties into the Indian Ocean. The dam created Lake Cahora Bassa, the second largest human-made lake in southern Africa. Prior to the dam’s construction, surrounding natural ecosystems and traditional agriculture were shaped by annual floods.
As the dam neared completion, experts recommended that Lake Cahora Bassa be filled slowly, over a period of at least two years. Furthermore, they recommended that a minimum flow be maintained, with extra releases to simulate natural flooding, and that the filling of the reservoir should not begin until after the 1975 flooding season. These recommendations were not followed.
The 1972 image shows a 250-km stretch of the Zambezi River prior to the construction of the Cahora Bassa Dam. The same stretch was flooded, in a single year, following the dam’s completion in 1974. In the ensuing years, flooding of the lower Zambezi has been notoriously mistimed. These erratic water releases have negatively impacted hundreds of thousands of downstream residents and decimated the ecosystem of the Zambezi River delta. The 2006 image shows the current extent of the reservoir. Strategies to better manage Cahora Bassa Dam are being explored in order to restore damaged ecosystems and some traditional land use.

Lake Chad
Located at the southern edge of the Sahara Desert, Lake Chad is bordered by Nigeria, Niger, Chad, and Cameroon. The lake was once the second-largest wetland in Africa, supporting a rich diversity of endemic animals and plant life. The Lake Chad drainage basin, a 2 500 000 km² hydrologically closed catchment, extends to eight countries: Algeria, Libyan Arab Jamahiriya, Niger, Chad, Sudan, Central African Republic, Cameroon, and Nigeria. It is home to over 20 million people who derive direct or indirect livelihoods from the lake. Most of the region’s rainfall occurs in the southern one-third of the Lake Chad drainage basin, contributing about 90 per cent of the basin’s runoff. The northern two-thirds, however, are dominated by arid conditions.
Climate variability and increased water consumption by the area’s inhabitants have changed the water balance within the Lake Chad drainage basin, and continue to do so. Since the early 1960’s, rainfall over the basin decreased significantly while irrigation increased dramatically over the same period. The lake is especially susceptible to climatic variability as it is rather shallow, with an average depth of 4.11 m. As a result of decreased rainfall and increased water usage, the extent of Lake Chad decreased by 95 per cent over roughly 35 years. More recently, water levels in Lake Chad have increased slightly. But the lake still remains a remnant of its former self.
As these satellite images from 1963 to 2007 show, the surface area of the lake has declined dramatically over time. The 2007 image shows significant improvement over previous years, but the extent of Lake Chad is still far smaller than it was three to four decades ago.

Lake Chapala
Mexico's Lake Chapala, lying in the heart of an extremely arid region, is the country's largest natural lake. The lake is one of the most important wetlands in the region and home to more than 70 endemic species. Since the 1950s, Lake Chapala has undergone many changes as a result of water abstraction for agricultural use both inside and outside the region and for a rapidly growing population. The level of the lake has declined, and there have been noticeable decreases in surrounding wetland areas as well as changes in the hydrological system connecting various springs.
Some of these changes are visible in this pair of satellite images, including alterations in the contours of the shoreline, obvious extensions of land near various townships around the lake, and the appearance of remarkably large areas of reclaimed land at the lake's eastern end. Like all arid areas, the land around Lake Chapala is prone to salinization. If the lake continues to shrink, researchers predict both a decrease in water availability and an increase in the salt content of the region's soil.

Lake Chivero
In 1952, the Manyame River was dammed 40 km southwest of Harare, creating Lake Chivero. The Lake was intended primarily as a water supply for Harare, but it is also a source of water for irrigation and industry and serves as a local fishery.
One year after Lake Chivero was created, water hyacinth, an invasive wetland plant, made its first appearance, as a result of the influx of nutrients from nearby agricultural lands and municipal and industrial wastes from Harare. In 1955/1956, the first serious water hyacinth outbreak occurred and was successfully treated with chemical herbicides. The next outbreak in 1971/1972 covered approximately 25 per cent of the lake. Attempts to end a third outbreak in 1986 used mechanical and chemical controls until public concern about the chemicals brought an end to their use. By 1989, water hyacinth covered 20 per cent of the lake’s surface (1989 image, yellow arrow); by 1990, it covered 35 per cent. Weevils that feed on water hyacinth were released as a biological control; mechanical and new chemical controls continued.
By 1997, it appeared that water hyacinth had been brought under control (see 2000 image). By 2005, however, the invasive plants were returning (2005 image), eventually covering a significant portion of the lake. In addition to water hyacinth, this most recent infestation includes massive amounts of another invasive plant, spaghetti weed (Hydrocotyle ranunculoides).

Lake Faguibine
Lake Faguibine is located in the Sahelian−sub desert zone to the west of Timbuktu in northern Mali. Annual precipitation in the Faguibine area is in the range of 250 mm/yr, with the rainy season beginning in mid-June and lasting 3 to 4 months. When full, the lake is among the largest in West Africa − an estimated 590 square kilometers in 1974 − and is an important source of water for the surrounding area (Landsat 1970s mosaic). In the late 1980s Lake Faguibine essentially dried up, making the traditional economic practices of fishing, agriculture and pastoralism difficult or impossible. It remains nearly dry in spite of normal rainfall in several of recent years (2006 image).
Lake Faguibine is at the end of a series of basins that receive water from the Niger River when it floods. This creates a close relationship between the flow of the Niger River and water levels in Lake Fagubine. Because of this, a lack of rainfall in either the Lake Fagubine catchment or the Niger River catchment upstream of the Niger Inland Delta can affect the water levels in the lake.
West Africa has a history of rainfall fluctuations of varying lengths and intensities. Sub−Saharan West Africa has experienced severe droughts in 1972, 1984 and 1992 and experienced a general trend of reduced rainfall from the early 1970s until the mid 1990s. The Lake Fagubine area in particular has seen a trend of decreasing rainfall since at least the 1920s. While water levels have also fluctuated widely in Lake Fagubine since the beginning of the 20th century, the period between the late 1980s and 2000 saw an extended period of low water with a complete drying up of the Lake in the 1990s. A 2003 Columbia University study links changes in Ocean temperature to drought in the Sahel in the 1970s and 1980s. There is speculation that global warming may be responsible for the recent increase in precipitation − since 2000 − and may continue to increase precipitation. In any case these findings "add another dimension to the variability of the global climate" and to the lives of peoples who rely on natural systems for their livelihood.

Lake Hamoun
Iran's Lake Hamoun is fed primarily by water catchments in neighboring Afghanistan. In 1976, when rivers in Afghanistan were flowing regularly, the lake's water level was relatively high. Between 1999 and 2001, however, the lake all but dried up and disappeared, as can be seen in the 2001 satellite image above.
The "dry phase" of Lake Hamoun is a striking example of how competition for scarce water resources can transform a landscape. When droughts occur in Afghanistan, or when water in watersheds that support Lake Hamoun are drawn down for other natural or human-induced reasons, the end result is a dry lakebed in Iran. In addition, when the lake is dry, seasonal winds blow fine sands off the exposed lakebed. The sand is swirled into huge dunes that may cover a hundred or more fishing villages along the former lakeshore. Wildlife around the lake is negatively impacted and fisheries are brought to a halt. Changes in water policies and substantial rains in the region saw a return of much of the water in Lake Hamoun by 2003.

Lake Ichkeul
Ichkeul National Park includes Lake Ichkeul and surrounding wetlands that form an important wintering and breeding area for migratory birds. It has been designated as a UNESCO Biosphere Reserve and a Ramsar Wetland of International Importance. Lake Ichkeul is fed by seven small rivers but is considered a lagoon because of its connection with the sea via Lake Bizerte to its northeast. During the wet season, Ichkeul fills with fresh water from these rivers. During the dry season, the lake’s water level falls, allowing an influx of saltwater from Lake Bizerte. These alternating conditions create an ideal environment for Potamogeton pectinatus (yellow arrows)—a pondweed and principal food source of migratory birds and waterfowl.
Construction of three dams along rivers that feed Lake Ichkeul modified this fragile ecosystem by decreasing freshwater inflow and increasing salinity during the dry seasons of 1977, 2001, and 2002. Two periods of drought (1993-1995 and 2001-2002) aggravated this trend, leading to an almost total disappearance of Potamogeton pectinatus from 1994 to 2002. In 2002, a mere 10 000 migratory birds came to Lake Ichkeul, the lowest numbers ever recorded.
The Tunisian government responded by increasing water releases from the dams. Helped by favorable rainfall conditions, the Potamogeton pectinatus started to recover in 2003, reaching 70 km2 in 2006 (2005 and 2007 images). Concurrently, migratory birds began returning. In 2004/2005 their numbers had climbed to 30 000.

Lake Jipe
Lake Jipe, along United Republic of Tanzania’s border with Kenya, is an important source of the Pangani River. As much of 75 per cent of the lake is infested by invasive aquatic plants, particularly cattails (Typha domingensis) and papyrus, or bulrush (Cyperus papyrus).
The bright green areas at the waters edge in the 1975 and 2005 images show these invasive plants covering parts of Lake Jipe. Coverage in 2005 is notably more extensive, especially at the northern end of the lake. The greyish patch there is evidence that the lake may be drying up. Research indicates that if current conditions continue, the lake may dry up completely within the next ten years.
The situation in Lake Jipe is the result of a vicious cycle. Drought reduces water levels in the lake, creating conditions in which the invasive plants flourish. The plants, in turn, encourage siltation and help draw down water levels even further.
The Pangani River Basin provides water for hydroelectric power plants at Nyumba ya Mungu and Pangani Falls, which provide at least 20 per cent of United Republic of Tanzania’s electricity. Increasingly low water levels in Lake Jipe and elsewhere have the potential to reduce power production. Low water levels have already affected the local fishing industry, forcing fishermen to move south to the Nyumba ya Mungu Dam. Projected water scarcity may also impact wildlife in Kenya’s Tsavo National Park.

Lake Kivu
Rwanda, Democratic Republic of the Congo
Lake Kivu on the Congo-Rwanda border is the highest lake in Africa at 1 459 m (4 788 ft). Beneath the lake lie vast reserves of methane gas which have not been exploited. Lake Kivu is also an important tourist center. These satellite images of Lake Kivu show dramatic changes before and after the eruption of Mt. Nyiragongo in January 2002. The 2003 image clearly shows the track of the lava flow, which traveled through Goma town and into the northeastern part of the lake, contaminating its waters. Lake Kivu is one of Africa's "killer lakes", containing a volatile combination of methane and carbon dioxide gases with the capacity to kill thousands of people.

Lake Malawi
Lake Malawi (Nyasa), the third-largest lake in Africa, is an essential water resource for Malawi, Mozambique, and United Republic of Tanzania. A 2003 study indicated that sediments and nutrients from densely settled areas surrounding Lake Malawi (Nyasa) are entering lake waters, increasing nutrient loading by as much as 50 per cent.
In these images, the bluish green swirls in the lake are algae blooms caused by these excess nutrients. Among other things, the algae reduce dissolved oxygen levels in the water. This poses a threat to the lake’s fish species. The algae blooms appear worse in 2006 (note their concentration along the lake’s western shore), suggesting that water quality may be continuing to decline.

Lake Manantali
Seasonal rainfall at the source of the Bafing River in Guinea has historically led to seasonal flooding along the Senegal River, which receives over half of its flow from the Bafing. Prior to the 1970s, this pattern of inundation provided the basis for flood recession agriculture that supported hundreds of thousands of people.
Drought in the 1970s, however, spurred the formation of the multinational Organization for the Development of the Senegal River (OMVS) to develop irrigation, power generation, and navigation. The Manantali Dam in western Mali was one of two large dams built as part of the OMVS project. These images show the vast extent of land inundated by the filling of the dam’s reservoir. Roughly 10 000 to 11 000 thousand people were displaced above the dam.
Below the dam, loss of the normal annual cycle of flood and recession reduced traditional agriculture substantially. Village-scale irrigation schemes have had limited capital for equipment and have been constructed without adequate drainage, resulting in soil salinisation. Flood recession farming was shown to give small farmers a better return with less risk than irrigated rice. Reduced flooding may also be contributing to deforestation along the Senegal River. The Manantali Dam did not produce any hydroelectric power until 13 years after its completion, and only after additional money was provided by the World Bank and others.

Lake Nakuru
Lake Nakuru is located in the Eastern Rift Valley in southwest Kenya. Lake Nakuru National Park is the second most visited protected area in Kenya. It hosts the world's largest concentration of flamingos, as well as many of the animal species that make Kenya a highly valued tourism destination, including lions, leopards, rhinoceros, and water buffalo. In its total area of 188 km² (73 square miles), there are over 450 bird species and 56 mammal species. Recognized as a wetland of international importance, Lake Nakuru was declared a Ramsar Site in 1990.
The threat of land cover degradation in the catchments of the lake is likely to increase flow fluctuation and decrease water quality. These images show the land cover degradation in the lake's catchment between 1973 and 2000.
In 2001, the Government of Kenya announced its intention to excise 353 km² (136 square miles) of forest in the Eastern Mau Forest Reserve (area with white boundary in the 2000 image). As a result, most of the forest cover in the upper catchment of the main rivers that feed Lake Nakuru will disappear.

Lake Sibaya
Lake Sibaya is narrowly separated from the sea by a range of high forested coastal dunes. The lake is home to large hippopotamus and crocodile populations, although their numbers have dropped over the last fifteen years due principally to poaching. The lakeshore is also home to the only known population of a rare climbing orchid. There has been an increase in cultivation of marginal lands around Lake Sibaya. Agriculture in the lake catchment and along its drainage lines may cause erosion, eutrophication, pollution, and the drying up of wetlands around the lake raising concerns among environmentalists. Although Lake Sibaya has been designated a wetland of international importance, there has been little effort by communities around the lake to practice sustainable management or to protect the rare species found in the region.

Lake Tonga
These two images show the dramatic human induced changes in and around Lake Tonga over the past 12 years. The damming of the feeder rivers of Lakes Tonga and Oubeira (shown in the bottom part of the 2000 image) has resulted in increasing irrigation around the dams and a drastic reduction in the volume of water entering the lake. The 2000 image was acquired during the rainy season, showing an increase in the water volume after the 1999 drought, which had left the lake virtually dry. The widespread ecological changes caused by the construction of dams around Lake Tonga should serve as an eye-opener to the community. Environmental Impact Assessments of the area could assist African policymakers with information to make informed choices about future projects.

Lake Victoria
United Republic of Tanzania, Uganda, Kenya
Shared by Kenya, Tanzania, and Uganda, Lake Victoria is the second largest freshwater lake in the world. The infestation of Lake Victoria by water hyacinth in the 1990s disrupted transportation and fishing, clogged water intake pipes for municipal water, and created habitat for disease-causing mosquitoes and other insects. This led to the initiation of the Lake Victoria Environmental Management Project in 1994. The focus of the Project was to combat hyacinth infestations on the lake, particularly the region bordered by Uganda, which was one of the most severely affected areas.
The 1995 image shows several water-hyacinth-choked bays: Murchison Bay near Gaba; large parts of Gobero and Wazimenya Bays; an area outside Buka Bay; and near Kibanga Port.
Initially, water hyacinth was controlled by hand, with the plants being manually removed from the lake. But re-growth quickly occurred. A more recent control measure has been the careful introduction of natural insect predators of water hyacinth. As the 2001 image shows, this approach seems to have been successful, as the floating weeds have disappeared from all the locations noted above.

Lappi
Finland is the most forested country in Europe; 86 per cent of its land area, or a total of 26 million hectares (64 million acres), is covered by forest. The country is responsible for one quarter of the world's printing and writing paper exports, and for one sixth of its paperboard exports. Feeding this massive paper industry is the Finnish forest industry - one of the most intensive in the world. As a result, Finland's forests - including its remaining old-growth fragments - are being exploited by clearcutting, forest thinning, road construction, and ditching of soils. The result is the severe and extensive fragmentation of natural habitat. While much of Finland's productive forest (around 62 per cent) is in the hands of private landowners, the vast majority of its valuable old-growth forest is owned and logged by the state. These two images show a result of this logging in the northeastern areas of the country. In the 1987 image, the area has a near homogeneous forest cover (green); on the other hand, the 2002 image shows only a few patches, mainly in the protected areas with continuous forest cover. The patches of tan signify clearcut areas.

Larsen Ice Shelf
Scientists have observed the ice along the Antarctic Peninsula disappearing in a series of retreats over the past 30 years. The climate in this area is warming at approximately 0.5 degrees Celsius per year following a trend that is believed to have been occurring for at least the past 50 years (NASA, 2006). Generally this retreat has occurred as icebergs break away from the oceanward edge of the ice. More recently a new pattern has been observed.
Scientists have been closely monitoring the Larsen Ice Shelf since 1995 when a large portion of it (Larsen A) dramatically disintegrated. In 2002 another similar event occurred at Larsen B which is captured in this remarkable series of MODIS images. In contrast to the slower pattern of calving - where pieces of ice break away at the edge of the shelf – these two events occurred over a large area and in a relatively short period of time. In the case of Larsen B 3,250 square kilometers of the ice shelf shattered into a plume of 1000s of icebergs in a little over a month. Over the last 5 years approximately 40 per cent of Larsen B has disintegrated – 5,700 square kilometers. Larsen A is believed to have been in place for over 2000 years at the time of its collapse and Larsen B is thought to have been still older (Portland State University, 2002).
Scientists have developed theories to explain Larsen B’s catastrophic collapse, linking it to summertime warming and the pooling of melted water on the surface of the ice (Scambos et al., 2000) as well as differences in the rates of movements of the several glaciers feeding into the ice shelf (Glasser and Scambos, 2008). The pooling water is believed to accelerate the expansion of crevasses and lead to the breakdown of the ice shelves. In addition, the differences in the rates of flow from various glaciers are believed to have created structural weakness in the ice shelf (Glasser and Scambos, 2008). In the case of Larsen B, ponds of melt water can be seen in the remote sensing images taken shortly before the collapse occurs (January 2002 image), lending credence to this theory. Melt water ponds have been seen forming on Larsen C in more recent images, however there appears to be less of the structural weakening from glacier flow on Larsen C and this may make it less vulnerable to catastrophic collapse.

Las Vegas
Las Vegas is the fastest growing metropolitan area in the United States. Its growth was fairly slow during the first half of the 20th century, but as the gaming and tourism industry blossomed the population increased more rapidly. In 1950, Las Vegas was home to 24 624 people. Today, the population of the Las Vegas Valley tops one million, not including the tourists. According to one estimate, it may double by 2015. This population growth has put a strain on water supplies.
Satellite imagery of Las Vegas provides a dramatic illustration of the spatial patterns and rates of change resulting from the city's urban sprawl. Las Vegas is shown in the central portion of these images from 1973 and 2006. Note the profound modifications to the landscape - specifically the proliferation of asphalt and concrete roads and other infrastructure, along with the displacement of the few vegetated lands. By 2006, Las Vegas' growth had sprawled in every direction, with the greatest expansion to the northwest and southeast. As the city expanded, several new transportation networks emerged to serve the city's inhabitants.

Leboudou Doue
In the black and white image, the darker areas of the land enclosed by this great loop on the Senegal River show the extent of the riverine forest in 1966. The 2006 image shows that very little of that forest remains.
Similar deforestation has occurred in the fertile floodplains along hundreds of kilometres of the Senegal River. Much of the forest was cleared by local people to make way for subsistence agriculture. The most common riverine tree species, Acacia nilotica, is also the preferred source of wood for fuel and construction, and for charcoal production. Production of charcoal for sale as far away as Dakar and Saint Louis has further increased the pressure on what remains of these woodlands. Acacia nilotica woodlands that covered 39 000 hectares along the Senegal River in 1966 had been reduced to 9 000 hectares by 1992—a reduction of 77 per cent.
These pressures were compounded by two developments in the late 1980s. In 1988, the Manantali Dam was built upstream in Mali. The dam controls roughly half of the Senegal River’s discharge. While controlled releases of water from the dam can recreate natural flooding, below-normal flood levels may be contributing to loss of Acacia nilotica stands. The area’s population has also grown dramatically over the past several decades, including the influx of some 120 000 Mauritanian refugees and Senegalese expatriates following an ethnic conflict in 1989.

Lesotho Highlands
In 1986, a treaty signed by South Africa and Lesotho initiated the Lesotho Highlands Water Project. The project design included a total of five dams, but committed the parties to only the first two dams and related infrastructure at a cost of over US$1 400 million. The project’s purpose was to deliver water to Gauteng Province in the industrial heartland of South Africa and hydroelectric power and income to Lesotho. In 1997, the 185-metre Katse Dam was completed on the Malibamatso River (upper right on 2006 image). The second phase of the project including the Mohale Dam (lower left on 2006 image) was completed in 2003.
The Lesotho Highlands Water Project has been controversial since it began, with concerns about both social and environmental impacts. More than 20 000 people were affected by Katse Dam and 7 400 by Mohale, including loss of homes, farmland, and communal grazing land. The 1991 image shows part of the project area before the dams were constructed. The 2006 image shows the areas inundated after both dams were completed. The first two dams, Katse and Muela (not shown) took approximately 1 900 hectares of croplands and Mohale a further 1 000 hectares. Together, the three dams decreased pastureland by 5 000 hectares. In addition to the impact on the immediate area, approximately 150 000 people are affected by reduced stream flow below the dams.

Mabira Forest Reserve
Mabira Forest, located in one of Uganda’s most densely populated districts, is the country’s only protected area of medium-altitude, moist, semi deciduous forest. The forest contains a wealth of biodiversity, provides a variety of services to local inhabitants, and is important to the area’s hydrology. The forest is under intense pressure from timber harvesting, charcoal production, fuelwood collection, and agricultural encroachment.
A 1989 study estimated that 29 per cent of Mabira Forest was lost between 1973 and 1988. The report also noted a significant increase in ecological disturbance in the areas of forest that remained. In the 2001 image, a large portion of harvested forest still shows the light green colours of young secondary growth (yellow arrows). The 2006 image shows that this secondary forest still remains largely intact and is maturing.
The Ugandan government plans to give much of this portion of Mabira Forest to the Sugar Corporation of Uganda (SCOUL) to expand its sugar plantations. This prospect sparked opposition protests in Kampala, 50 km to the southwest. While the government argues that the need for economic development justifies the loss of the forest, many environmental groups have opposed the move, citing the value lost in biodiversity, ecosystem services, timber production, eco-tourism, and carbon sequestration credits, which can be traded on the world market.

Mahe Island
The east coast of Seychelles’ Mahe Island has undergone major environmental change during the last 30 years, primarily due to land reclamation projects. In 1973, land was reclaimed to create a site for the Seychelles International Airport, and in 1986, for a new port facility. Two further phases of reclamation were completed in the early 2000s, parts of which can be seen in the 2007 image (yellow arrows).
These reclamation projects have impacted both marine and coastal environments. Several new wetland areas have been created, some of them colonized by mangroves, which provide valuable bird habitat and nursery areas for marine species. However, sedimentation from reclamation projects has killed some of the coral along Mahe’s eastern coast as well.

Manaus
Manaus, the capital of the state of Amazonas, is located on the north bank of the River Negro at its confluence with the Solimoes River, which extends eastward as the Amazon River. The population of Manaus grew by more that 65 per cent between 1993 and 2003 to its current population of over 1.5 million.
These two Landsat images document the conversion of forest areas due to logging and urbanization between 1987 and 2001. The city of Manaus can be seen in grey toward the lower right corner of the images. In addition to the urban expansion evident in the area surrounding the city, increased logging and road construction can be seen in the 2001 image. The rectangular area of mature forest on the northern border of the city is the Adolpho Ducke Forest Reserve.
About 15 kilometers from Manaus, Rio Negro (Black River) meets Rio Solimoes to create an amazing confluence of the brownish white water from the Saliomes joining the black water (caused by the very high acidity from tannin) from the Rio Negro. The Rio Solimoes appears blue in this image, the Rio Negro black. The black waters of the Rio Negro are not completely absorbed until many miles after the two rivers merge.

Manzanar Mangrove Project
Along 15 per cent of Eritrea’s coast there are stretches of green that contrast with the arid environment surrounding them. They are mangroves—stands of salt tolerant trees and plants that can get their water from the sea. Dr. Gordon Sato, a retired molecular biologist, wondered why they occur only intermittently rather than along the entire coast. He discovered that streams flowing into the Red Sea during seasonal rains provide nutrients that the mangroves need to grow. He devised a simple means of delivering these missing nutrients, allowing mangroves to be grown on otherwise barren shoreline.
These mangroves flourish with low cost applications of fertilizer. The 2007 image of the coast near Hagigo, Eritrea, show how quickly the seedlings are growing into stands of mangrove trees (outlined areas). The mangrove’s leaves provide fodder for sheep, which in turn are a source of food for the Eritrean population.
The so-called Manzanar Project aims to develop self-sufficiency in Eritrea, village by village. Coupled with aquaculture, the mangroves provide both a land- and sea- based economy that might eventually be developed for the specialty seafood export market.

Mashonaland Central Province
In the 1980s and 1990s Zimbabwe was known as the breadbasket of southern Africa. It was self-sufficient in maize production and had large commercial farms which brought foreign currency into the country through the sale of tobacco and other export crops. Since 2000 the country has seen a dramatic decline in agricultural production and has needed to import maize to address food shortages. For the 2006/2007 marketing season the Famine Early Warning Systems Network (FEWS NET) predicted a cereal grains shortfall in Zimbabwe of approximately 22 per cent.
While there have been some periods of drought during this time, the deficits in agricultural production exceed the levels that would be caused by drought alone (Smith et al., 2006). Western governments claim that the food shortage is the result of government policies in Zimbabwe, particularly a land reform policy that has taken many large farms out of the hands of experienced farmers.
While the causes have been contested by the government, there is no denying that there have been food deficits in Zimbabwe over the last 5 years. In addition remote sensing imagery provides evidence that the large productive commercial farms have been broken into smaller farms. In the August 2001 ASTER image many large farm fields can be seen in bright green. By the time of the August of 2005 ASTER image many of these same farms have been broken into smaller fields.

Mendenhall Glacier
United States of America, American Samoa
Mendenhall Glacier flows 22 kilometers from an elevation of nearly 1,600 meters in the Coast Mountain Range, to just above sea level at its terminus roughly 5 kilometers northeast of Juneau, Alaska. It has been receding since the 1700s when the “Little Ice Age” ended, retreating approximately 3 kilometers in the past century. Most of this retreat occurred in the mid-1940s and the late 1990s.
The majority of the global community now accepts fluctuations in glaciers, particularly changes in their volume, to be reliable indications of a global trend of warmer air temperatures. While the retreating tongues of glaciers are less directly linked to climate change than overall volume, they are much more readily observed and allow the study of glaciers which would otherwise be out of the reach of most research projects. It is believed that the current climate conditions will not be reflected in most glacier tongues for years and will eventually amount to a kilometer or more of additional retreat. If climate conditions continue to follow current trends many glaciers will disappear completely.
The satellite images from 1986 and 2007 show the continuing retreat of Mendenhall Glacier. Similar changes are taking place in many of the glaciers in southeastern Alaska. A 2002 study estimated the contribution of melting Alaska glaciers to sea level rise between the 1950s and 1990s to be twice that of the melting of Greenland’s ice sheet during the same time period.

Mesopotamia Marshlands
Located at the confluence of the Tigris and Euphrates rivers, the Mesopotamian marshlands are one of the world's great wetlands covering an estimated original area of 15 000 - 20 000 km² (5 792 - 7 722 square miles) The marshlands are an important center of biodiversity, play a vital role in the intercontinental migration of birds, and have long supported unique human communities. Upstream damming as well as drainage activities in the marshlands themselves have significantly reduced the quantity of water entering the marshes. Together these factors have led to the collapse of the ecosystem. Restoration of the marshlands, mainly through reflooding by breaching of dykes and drainage canals has begun. As a result of these activities, vegetation and wildlife have returned to some parts of the marshes.
Remote sensing images provide a synoptic illustration of these changes. In 1973 the original marshlands were largely undisturbed. The 2000 image reveals the area after being drained, with most of the wetlands having disappeared. On the other hand, the 2004 image illustrates recovery in progress with major portions in the central and western sections having been restored to some extent.

Mexico City
Mexico City is one of the fastest growing megalopolis cities in the world. These satellite images show the transformation Mexico City underwent between 1973 and 2000. Areas of urban infrastructure appear as shades of purple while natural vegetation is shown in green. In 1973 Mexico City had a population of about 9 million. In the ensuing years, the city expanded into surrounding areas. The forests in the mountains west and south of the city suffered significant deforestation as the urban sprawl progressed. By 1986, Mexico City's population had soared to 14 million. In 1999, Mexico City had a population of 17.9 million, making it the second largest metropolitan area in the world behind Tokyo, Japan. The Mexican megalopolis is expected to reach 20 million in the next few years.

Midrand
Midrand is located approximately halfway between the major urban centers of Johannesburg and Pretoria in South Africa. The major highway that connects these two large cities bissects the city of Midrand into east and west halves. Since 1978, the city has been rapidly transformed as a result of population growth, agriculture, mining, and industry.
In the 1978 image, the area surrounding Midrand consists largely of agricultural lands and rural residential zones, with some evidence of commercial development. The 2002 image reveals high-density urban development throughout. Rapid growth of Midrand's economy is expected to continue. Current development trends and population growth rates indicate that if effective environmental management strategies are not adopted soon, significant deterioration in the quality of the environment can be expected.

Mikea Forest
On an island known for endemic species, the South Malagasy spiny forests in the southwestern corner of Madagascar are one of the islands most distinct ecosystems. Within Mikea Forest, the unusual Didierea madagascariensis and Euphorbia stenoclada as well as the more common Adansonia fony are among the most widespread tree species. Mikea Forest is also home to many endemic reptile and bird species. Two bird species unique to the Mikea Forest, the sub-desert mesite (Monias benschi) and the long-tailed ground-roller (Uratelornis chimaera), are classified as vulnerable.
The area of Mikea Forest shown in these images has lost approximately 28 per cent of its primary forest cover in the last three decades and the rate of loss appears to be accelerating. The white dashed line shows loss between 1962 and 1999. The 2002/2003 image shows deforestation advancing still further to the west.
A large portion of the forest has been lost to charcoal production, most of it for commercial sale in Toliara. This is especially true at the southern edge of the forest where road accessibility is greatest. Further north, slash-and-burn maize cultivation is practiced by the Mikea people native to the area. Most of this maize is for local consumption. This appears to be the driving force of forest loss along the eastern edge of the forest, which has moved almost 10 km to the west since 1973.

Morondava
The large circular fields of irrigated sugarcane near Morondava in western Madagascar are an anomalous sight in this area more known for its baobab trees. While the average temperature in the area is ideal for sugarcane cultivation, a long dry season (April to November) makes irrigation necessary. The 1973 image shows the region before the plantations were established while the 2006 image shows prominent “centre pivot” irrigated plantations. In 2006, roughly 22 000 metric tonnes of sugar were produced here, most of which was exported.
Baobabs, sometimes called “upside down trees” can live for up to 5 000 years. While there is only one baobab species on the African continent, Madagascar is home to seven different species. The volume of water needed for irrigating sugar cane fields may threaten the survival of these ancient trees if sugar cane farming extends into baobab areas—particularly the “allée des Baobabs” (Baobabs Boulevard, yellow arrows). Baobabs are also under threat by local community involved in rice farming. Since August 2007 the “allée des Baobabs” has been temporarily classified as a protected area, the result of consultation between local communities, local authorities, and government authorities.

Moskva
Moskva - Russia's capital city and its political and economic heart - sits on the far eastern end of Europe, roughly 1 300 km (815 miles) west of the Ural Mountains and the Asian continent. The Moskva (Moscow) River winds through the city, and the Kremlin, the seat of the Russian government, lies at its center. With a population close to 9 million and an area of 1 035 km² (405 square miles), Moskva is believed to be the largest of all European cities.
These two images show the urban expansion Moskva experienced during the last 25 years of the 20th century. The blue-gray patches are urban areas. The light green areas surrounding the city are farms while the brown areas are regions of sparse vegetation.

Mt. Cameroon
Mount Cameroon, in the country’s southwest corner, is among the most active volcanoes in Africa. Rising 4 095 metres above the nearby Atlantic coast, it has erupted seven times in the last century, most recently in 1999 and 2000. The mountain is home to many rare birds and plants. In addition, there are several small communities near the volcano that are at risk from direct and indirect impact of volcanic activity.
In the 1979 satellite image, the tracks of several old lava flows can be seen although the volcano had not erupted since 23 January 1959. In the 1986 image, a lava flow is visible on the southwest flank of the mountain (yellow arrow), the result of a 1982 eruption. The image from 2000 shows large lava flows left by the 1999 and 2000 eruptions (yellow arrows).
The principal vent of the 1999 eruption was at about 1 400 m elevation. It sent a voluminous lava flow estimated at about two kilometres wide and 30 m thick in a south-southwest direction. The flow eventually extended roughly seven kilometres, burning through dense rain forest, industrial palm plantations, and small subsistence farms, and flowing across the important Limbe-Idenau road. The village of Bakingili was evacuated over concerns that the hot lava entering the sea might pose a health threat. In 2000, Mount Cameroon erupted again, with two main lava flows moving down the volcano’s southern flank.

Mt. Kenya
Mount Kenya has been described as one of the most impressive landscape features in East Africa. In addition to its beauty and value for timber, farmland, and tourism, it is a critical water catchment for Kenya and crucial to hydro-power generation on the Tana River. Depending on altitude and rainfall, there are a variety of different ecosystems on Mount Kenya, which are visible to some degree as various shades of green in the 1976 satellite image.
After independence in 1963, the Kenyan government encouraged settlement of the Mount Kenya region and over a period of roughly forty years population increased ten-fold. In the late 1990s it was recognized that this intense population growth, along with misuse of non-resident cultivation policies, illegal charcoal production, illegal forestry, and marijuana cultivation were threatening the future of Mount Kenya. New policies and improved enforcement have significantly reduced unsustainable exploitation of the mountain’s forests.
Continued monitoring and management of this majestic mountain is aimed at maintaining its immeasurable value for future generations. Sustainable uses such as eco-tourism help provide employment without undermining the essential ecosystem functions and invaluable biodiversity of this natural asset.
Insets A, B, and C are high resolution images of 3 areas whose land cover compositions have been altered by various human activities.

Mt. Kilimanjaro
Glaciers on the summit of Mount Kilimanjaro have decreased in area by 80 per cent since the early 20th century. While glacial retreat globally has been linked with rising air temperatures, there is evidence that the decline of Kilimanjaro’s glaciers, along with changes in the boundaries of vegetation zones on the mountain, may be due in large part to a more local trend of decreasing precipitation that began in the 1880s.
It has also been found that water from the melting of Mount Kilimanjaro’s glaciers provide little, if any, water to lower elevation streams, as most ice is lost through sublimation; water from the small amount of melting evaporates very quickly. A greater impact on the mountain’s hydrology may result from increased burning under the drier conditions since 1880. The upper limit of the forest zone has descended significantly, as nearly 15 per cent of Kilimanjaro’s forest cover has been destroyed by fire since 1976. In the 1976 image, the upper limit of the Erica excelsa forest is shown in yellow. By 2000 the upper limit had moved noticeably downslope (red outline) as a result of frequent fires. Changes in the hydrological and ecological functioning of Kilimanjaro impact a growing population living on and around the mountain.

Mt. Saint Helens
Mount St. Helens is located in the state of Washington on the west coast of the United States. It is part of the Cascade Range, which is dominated by periodically active volcanic peaks. For most of the 20th century, the snow-covered mountain was known for its quiet beauty, until on 18 May 1980, the top 420 m (1 300 ft) disappeared within minutes. The blast leveled 400 km² (249 square miles) of forest, formed a deep horseshoe crater, and sent thousands of tonnes of ash into the upper atmosphere. A major debris flow filled a valley 24 km long (15 miles). Sixty-two people were dead or missing. This eruption of Mount St. Helens was the most destructive in the history of the United States, with total economic losses estimated at US$1.2 billion (NGDC 2004). Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash (USGS 1999). Lessons learned from this and other volcanic activity in the Cascade Range will be invaluable to scientists for predicting such events and anticipating their ecological impacts (UNEP 2003).

Mulanje Massif
Rising to 3 000 metres, Mount Mulanje is the tallest peak in south-central Africa. It is an important source of water for almost every river that runs through southern Malawi. Mulanje Mountain Forest Reserve was created in 1927, primarily to safeguard the water catchments and to control the extraction of the endemic Mulanje cedar—Malawi’s national tree.
Forest cover in and around the park is threatened by agricultural conversion, wildfires, fuelwood collection, and invasive species. Between 1973 and 2006, the top of the mountain underwent notable deforestation.

Mutarara-Sena Conflict Agriculture
Cropland Use Intensity (CUI) in Mozambique was negatively affected by the post-independence war in that country after 1975. Mozambique was a colony of Portugal until 1975, when an 11-year war of independence ended with the establishment of an independent government. But a 17-year civil war started soon after independence.
The civil war affected Mozambicans severely, especially in rural areas. Hundreds of thousands of people were killed. Over a million people fled the country, especially to Malawi, and more than a million others were displaced within Mozambique. Many rural people migrated to the cities, especially along the coast where the government maintained control. The country went into severe economic depression. Agriculture was disrupted, so the country could not feed itself. By the late 1980s Mozambique had one of the lowest per-capita caloric intakes in the world.
Landsat satellite imagery of 15th August 1973 around the town of Mutarara, just before Mozambique got independence, shows high agricultural activity to the top center of the image, indicated by the bright green rectangular patterns north of the small town of Tembe-Tembe. This equates to high cropland use intensity before the war started in 1975. A look at the 24th February 1992 satellite image shows a drastic decrease in agricultural activity, and hence cropland use intensity, in the same area after the war. The prevalence of a brown color in the better part of the image is an indication of the lack of vegetation; arguably due to a lack of agricultural activity. Three years later as can be seen in the 20th April 1995 Landsat image, there is an increase in the green vegetation and the acreage of agricultural fields north of the same study area north of Tembe-Tembe. The final Aster satellite image of the study area shows the largest coverage of healthy green vegetation and agricultural fields, several years after the end of the civil war in Mozambique. This study carried out by Crawford, et al. (1996) is an indication that cropland use intensity decreases due to the effects of war, and increases when political stability and peace prevail in a state.
The US Agency for International Development (USAID) runs the Famine Early Warning System (FEWS), which monitors drought-prone countries in Sub-Saharan Africa, to quickly detect droughts and crop failures which could lead to mass hunger and starvation. The US Geological Survey EROS Data Center (EDC) carried out the CUI study presented herein in support of FEWS’ efforts (Crawford et al., 1996).

Myebon
Myebon, Myanmar is in the coastal state of Arakan where many of Myanmar's mangrove forests are located. Several large areas of mangrove were cleared for agriculture and other uses (e.g. paddy fields and salt pans) between 1979 and 2000. The large areas of gray and tan that appear in the previously deep green areas show where the mangroves have been cleared.
Mangrove ecosystems occur at the transition between the marine and terrestrial ecosystems and provide important services to both. They are nursery areas for the breeding of many marine species and essential for maintaining healthy fisheries. They are also prime habitat for migratory birds, amphibians and many terrestrial species. Mangroves are under pressure throughout much of coastal South Asia where they are being cleared for agriculture, aquaculture and urbanization. Protection of mangrove areas such as these will become increasingly important to preserving the dwindling areas of viable mangrove forest throughout the tropics.

Nangbeto Reservoir
A feasibility study in the 1960s identified the Nangbéto region as the best location for hydroelectric power development in Togo. The site - 160 km upstream from the coast – is the only place where a dam of sufficient volume to regulate the flow of the Mono River was possible. As demand for electricity grew, the decision was made in the 1980s to proceed with the Nangbéto Hydroelectric Dam.
Satellite images from 1986 and 2001 show the region before and after the dam’s construction. The completed dam created a reservoir with a surface area of approximately 180 km2 and a volume of 1 465 million m3. In addition to generating electricity for domestic and commercial use, the dam also provides water for agricultural irrigation and is a source of commercial fishing and tourism. However, these benefits have been offset by environmental costs.
Construction of the dam, creation of the reservoir, and installation of transmission lines resulted in the loss of nearly 150 km2 of savannahs and gallery-forests that provided habitat for rare local fauna. The reservoir submerged 1 285 households and 5 500 hectares of agricultural land. Loss of the natural vegetation in the region has altered the climate enough to have had a negative impact on nearly 350 hectares of banana plantations. The creation of the reservoir has also increased the population of two species of aquatic snails that serve as intermediate hosts of the parasite that causes the disease bilharzia.

Narok
The Narok District, located in southwestern Kenya, is one of eighteen districts in the country's Rift Valley Province. The primary inhabitants of the district, the Maasai, have traditionally been nomadic pastoralists. However, conversion of portions of their grazing and hunting grounds into national parks and game reserves, including Mara (Maasai Mara Game Reserve), Serengeti, and Tsavo, has posed a challenge to their way of life. Diminishing income from cattle raising and tourism activities has led to the conversion of Narok's fertile soils into productive agricultural lands. With World Bank estimates of US$0.75 per annum per hectare for cattle, US$5.5 for tourism and US$218.75 for farming, the tendency for grasslands conversion into to agricultural fields seems only logical to many. By 1987, more than 27 000 hectares (66 718 acres) of land had been leased to farmers, an increase from 18 000 hectares (44 478 acres) in 1973.
These two images reveal the changes that have taken place in the Narok grasslands area over the past three decades. In the 1975 image, agricultural expansion is just beginning, while the 2000 image shows the degree to which farmlands have expanded.

Niger Delta Oil
The Niger River Delta spans the coast of Nigeria from the Benin River in the west to the Imo River in the east. The delta supports the world's third-largest mangrove forest, and is home to over 150 species of fish, West African manatees, hippopotamuses, spot-necked swamp otters, and rare pygmy hippos.
Since the discovery of oil in the delta in the 1950s, the promise of improved lives through a share of the oil wealth has eluded area residents. Instead, they have found their traditional livelihoods increasingly undermined by environmental degradation.
The 1984 image shows the delta 20 years after oil operations began in the early 1960s. Considerable infrastructure is already in place. In the 2003 image, some of the wells (yellow arrows) and the pipelines connecting them can be seen. Also visible are a large storage facility, liquefied natural gas plant and terminal station on Bonny Island in the lower right corner of the image and another oil storage facility just south of Port Harcourt (red arrows).
Currently, about 66 gas fields and over 500 oil wells are located in the delta area. Between 1976 and 1996 there were more than 4 640 oil spills totaling three million barrels of oil. In addition, between 70 and 90 per cent of the natural gas from these oil fields is flared (burned as waste), releasing massive amounts of carbon dioxide into the atmosphere, causing local air pollution and acid rain, and wasting roughly US$300 million per day worth of energy.

Novovolynsk
The unique transformation of the former USSR into today's modern states has had a profound effect on the layout of the land in Ukraine. These images show a notable difference in the agricultural land use patterns between Poland and Ukraine, probably reflecting different policies and approaches to land use. Of particular interest are the sizes and patterns of the agricultural fields in the two countries.
Though the town of Novovolyns'k has not changed appreciably in size, an apparent change in the approach to land use in Ukraine has taken place; in the 2000 image, larger fields have been divided, following the pattern in Poland. The satellite images reveal quite vividly the contrast in land-use practices between the individual farms of Poland and Ukraine's former state farm planning, and how the latter has changed over time.

Ok Tedi Mine
The controversial Ok Tedi copper mine is located at the headwaters of the Ok Tedi River, a tributary of the Fly River, in extremely rough terrain in the rainforest-covered Star Mountains of Papua New Guinea's western province. Prior to the opening of the mine in 1984, this area was very isolated, sparsely inhabited, and ecologically pristine. This pair of satellite images reveals the tremendous environmental impact the mine has had in 20 years. The uncontrolled discharge of 70 million tonnes of waste rock and mine tailings annually has spread more than 1 000 km (621 miles) down the Ok Tedi and Fly rivers, raising river beds and causing flooding, sediment deposition, forest damage, and a serious decline in the area's biodiversity. In the 1990 image, both the mine and the township of Tabubil - developed east of the river in support of the mine - are clearly visible. Lighter patches of green show disturbance of the original forest cover from subsistence agriculture, road clearing, and other infrastructure development.

Okavango Delta & Lake Ngami
The vast stretches of grassland, wetland, and open water of the Okavango Delta are home to a variety of wildlife and vegetation as well as several native tribes. Although the Okavango ecosystem is considered one of the wonders of the world and attracts tourists from all over the globe, it faces several significant threats.
Proposed upstream water projects are among these threats. The Okavango River originates in the highlands of east-central Angola and brings the flood waters and sediment necessary to maintain the dynamic flooding of the delta. Upstream dams could trap much of this sediment, causing the river’s channels to erode. These deeper channels would likely become established as the few permanent channels, thereby depriving vast areas of life-sustaining floods. Nevertheless, there is an increasing pressure to divert water from the river for agriculture in Namibia and Angola.
At the southernmost tip of the Okavango Delta lies Lake Ngami, a significant breeding ground for birds (double click the 2003 layer). Historical records and recent satellite data suggest the lake has declined significantly over the past 150 years. For roughly the last century the lake has been fed primarily by flood waters that make it through the wetland into the Kunyere and Nghabe Rivers. Should flooding decrease or cease in the delta, the lake would likely dry up entirely. Decreasing water levels have already led to a paved road across a part of the lake which has been dry for several years.

Olympic Peninsula
On the slopes and the surrounding areas of Mt. Olympus in the Olympic Peninsula of the Pacific Northwest, one of the last remnants of temperate forests in the United States is quickly disappearing. Between 1971 and 2002, nearly half a million hectares (1.1 million acres), or almost 29 per cent of the forest covering the Peninsula, was clear-cut. That is an area equal in size to the Olympic National Park and its five adjacent wilderness areas.
The 1974 image shows the characteristic patchwork of purple and pink areas where clear-cutting has taken place. Light green patches signify regrowth in the forest areas. On a percentage basis, forests owned by Native tribes on the Peninsula were the most severely impacted during this period of time: 48 per cent of the forests on Native lands were clear-felled. In the 2000 image, clear-cutting is obviously still continuing, as is development to the north, west, and south of the national park. There is evidence of good regrowth of trees in forest reserve areas in preparation for the next clear-felling cycle.

Omo Delta Wetlands
The Omo Delta is located at the north end of Lake Turkana, a large closed-basin lake located primarily in Kenya. The Omo River provides most of the lake’s water. The 1973 image shows the delta entirely within the boundaries of Ethiopia. By the time the 2005 - 2006 image was acquired the southern most point of the delta was roughly 12 km to the south and had crossed the Ethiopia-Kenya border.
While the relative contribution of several causes is uncertain, reduced lake levels are believed to be the primary cause with an increase in sediment inflow also contributing. Decreased rainfall, increased upstream diversion of water, and increased evaporation due to higher temperatures all likely contribute to the lower lake levels. Soil disturbance for agriculture has increased erosion and increased the inflow of sediment to the lake. The fact that the delta now falls in two countries has complicated its management.
The increasing area of the delta has provided new land for the 20 000 Dassanech people - traditional inhabitants of the delta. Primarily pastoralists, the Dassanech also grow millet, maize, and beans on the delta. In the fall of 2006, severe flooding killed around 100 Dassanech and destroyed houses, crops, and infrastructure.

Ouagadougou
Urban population in Burkina Faso grew 200 per cent between 1975 and 2000 and is projected to continue expanding at a similar pace over the next quarter century. The capital, Ouagadougou, was home to approximately 40 per cent of Burkina Faso’s rapidly growing urban population, with 1.2 million residents in 2003. In the 1980s, much of Ouagadougou’s growth was the result of rural to urban migration of young people; however, by the mid-1990s natural growth had become the main factor.
In spite of government attempts to manage it, much of the residential growth in Ouagadougou has occurred in unplanned settlements at the periphery of the city. Because of the sprawling nature of these settlements, the city occupied 14 times more area in 1993 than it had only 33 years earlier. By the early 1980s, 60 per cent of the urban area was occupied by unplanned settlement. Much of this growth was concentrated in the south to southwest perimeter, a trend already apparent in the 1986 image. The 2004 image shows more recent growth has been concentrated in the south and east.
Unplanned settlements limit future possibilities for planned development and further complicate delivery of basic services. The problem of an insufficient water supply is already being heavily felt. In addition, space used for these settlements is lost to other uses, including agriculture and wildlife habitat.

Ouargla Oasis
Ouargla, located in the sands of the northern Sahara Desert, overlies the North-West Sahara Aquifer (NWSA) which extends underneath Algeria, Tunisia and Libyan Arab Jamahiriya. Use of the superficial water table of the NWSA extends back to ancient times. In the 19th century, bore holes were drilled to access deeper parts of the aquifer. By the 1970s there were roughly 2 000 bore holes on the NWSA. These wells now provide water to irrigate approximately 500 000 date palms surrounding Ouargla.
The region’s traditional irrigation methods used sustainable amounts of water. Modern, more intensive irrigation methods can lead to degraded water quality, decreased water levels, and loss of artesian pressure, as well as salinization of the superficial water table and the soil. Natural drainage conditions and insufficient engineered drainage have already led to accumulation of water near the surface and a concentration of minerals. This salinized water at a depth of 0.5 to 1.5 m below the soil surface is detrimental to palm trees.
The 1976 image shows date palms surrounding Ouargla and Chott Aïn El Beïda, a saline depression that has collected irrigation runoff for generations. The 2006 image shows a proliferation of irrigated land, which, without proper management, will not be sustainable.

Oudomxay
Laos (The Lao People's Democratic Republic) is a small land-locked country in Southeast Asia that is rich in forest and water resources. However, human agricultural practices such as uncontrolled burning and shifting cultivation - a land-use pattern in which patches of forest are cleared, burned and cultivated, and then abandoned to allow regrowth and recovery before being exploited again - are the primary causes of deforestation throughout the country. A comparison of these 1975 and 2000 satellite images shows how the intensity of shifting cultivation activities - and the resulting environmental damage - has increased over time. In 1975 there were only scattered areas under cultivation (white patches) in the forest. By 2000, the number and size of cultivated areas and disturbed forest cover had increased substantially.

Ouemé Flood Plain
Benin’s capital city, Porto Novo, and its largest city, Cotonou, lie within the floodplain and watershed of the Ouemé River. They share this important water system with Lake Nokoué and Porto Novo lagoon. The Ouemé River is home to over 120 species of fish; the greatest concentration of them occurring in the lower reaches of the river basin. Almost all of them are used for human consumption. The wetlands in the system serve as important nursery and feeding grounds for many of these species. They are also important habitat for many of the 233 bird species found in Benin.
In addition to its biodiversity, the coastal zone plays a key role in the economy of Benin. Fishing, agriculture, and other economic activities within the coastal zone provide 70 per cent of the country’s total GDP and livelihoods for much of Benin’s population. Population pressure and the drive to boost the gross production from the coastal zone without proper environmental management threaten the integrity of the productive resource base and biodiversity resources. Illegal logging is a serious problem throughout the whole catchment. Between 1986 and 2000, dense forest in this area was reduced by more that 40 per cent. The 1986 image shows several areas of forest cover that by 2000 have been seriously degraded or lost. Most obvious are three rectangular patches that completely dissappeared between 1986 and 2000 (yellow arrows).

Ouesso
Ouesso, the largest town in northern Republic of the Congo with roughly 25 000 people, is surrounded by relatively intact tropical rain forests with a range of fauna including elephants, gorillas, chimpanzees, and bongos. Bushmeat accounts for the vast majority of protein in the diet of local people. Hunters largely ignore laws governing the taking of wild game; the harvest is only limited by accessibility and technology.
Inaccessibility of the area around Ouesso has also limited timber exploitation. Of seven companies logging in the area in the 1990s, four went bankrupt under the burden of high transportation costs. However, the area’s inaccessibility appears to be changing. In the 1976 image few roads are visible and towns in the area are quite small, with little visibly disturbed forest surrounding them. By 2003, roads have penetrated throughout the area, towns have grown significantly, and, particularly near Pokola, the area of disturbed forest has grown (yellow arrows).
Logging roads, vehicles, and increased job opportunities have been shown to dramatically increase the range in which bushmeat hunting takes place. It also changes hunting from a subsistence activity to a commercial activity with meat being transported as far away as Brazzaville. There is a proposal to build an Ouesso-Brazzaville rail line. Improved transportation at lower cost would likely bring more roads, increased logging, and further increase in the bushmeat trade.

Paektu San
Democratic People's Republic of Korea, China
Situated on the border between China and North Korea, the mountain Paektu San is a symbol of patriotism for the Korean people and an embodiment of their national spirit. The mountain's rich volcanic soils and its dry, relatively cool climate make it suitable for agriculture.
These two satellite images reveal the degree to which agricultural activities have expanded on and around Paektu San, particularly on the North Korean side of the border, where intensive land development has served to both increase food production and underscore North Korea's territorial claims. In these images, green represents natural vegetation while grayish-brown areas are bare agricultural lands in which crops have not yet emerged from the soil. Areas of deforestation and other types of land clearing appear pink and are dissected by the fine lines of mountain streams. Near the center of the more recent image, there is further evidence of land-cover change along the border between the two countries where a dam has been constructed.

Papua
Indonesia is the second largest producer of palm oil in the world, after Malaysia. The drive to meet the demand for palm oil is resulting in conversion of forested areas into palm oil plantations. These three satellite images reveal how a combination of transmigration, logging interests, and palm oil plantation development have transformed an area that was previously tropical lowland rain and swamp forest.
While the 1990 image shows the first signs of development in this region, with the jagged access road network forming the only break in the forest cover, the October 2000 image reveals an area being prepared for palm oil plantations, and evidence of an influx of plantation workers. The 2002 image clearly shows a checkered pattern of plantations in the primary development area, and the extension of the road network to the north, south, and southwest.

Paris
France is a large country with relatively few large metropolitan areas. Only 16 French towns and cities have populations of more than 150 000 people. Paris, the capital city of France, is the largest of these and home to roughly 2 million inhabitants. The entire Paris metropolitan area, however, includes more than 11 million people.
Lying roughly 160 km (100 miles) southeast of the English Channel in northern France, Paris is considered by many to be one of the most beautiful cities in the world. In the images above, the Seine River can be seen winding its way through the heart of the city. Urban areas appear gray and purple. The patchwork of green, brown, tan and yellow around the city is primarily farmland. Note how the city has expanded in the years between 1987 and 2001, reaching ever-further into the surrounding rural areas.

Peanut Basin
While much of West Africa is experiencing loss of woodland and forest cover from expanding cultivation, Senegal's major agricultural region - the Peanut Basin - is witnessing the opposite: agricultural lands are being abandoned, and replaced with tree-dotted savannas. This pair of Landsat images shows the growing patchwork of savannas (greenish patches) where peanut and millet crops once prevailed. This phenomenon is not the result of a planned land management program. Rather, it stems from recent trends in out-migration. The drop in world market prices for peanuts, drought, and the removal of government agricultural subsidies have made it difficult for farmers in the region to continue to farm. Since the 1980s, many have left in search of new livelihoods in Senegal's urban areas, including Darou-Mousty (upper right), and the major centers of Touba and Dakar (not shown) as well as abroad. Those who have stayed are enjoying the benefits of a revived rotational fal­low system, large tracts of grazing land for a growing livestock economy, and diversification into other cash crops. Hundreds of villages can be seen scat­tered throughout this region (dark spots).

Phnom Penh
Phnom Penh (pronounced p-NOM PEN) is the capital city of Cambodia. It is just west of the four-way river intersection, which is called the Chattomukh ("Four Faces"). From the northwest and northeast, respectively, flow the Tonle Sap and Mekong Rivers. These waters merge and split into the Basak River and the Mekong, which flow southeast to the South China Sea. The Mekong river is the 12th longest in the world, flowing from western China to the Mekong Delta in southern Vietnam. Every autumn, monsoon rains are too great for the Mekong to carry, and it floods a large area of Cambodia. This flood even reverses the flow of the Tonle Sap River, northward to the Tonle Sap ("Great Lake") which can expand to ten times its normal size.
This pair of images shows the extent of flooding associated with the two rivers. The 2000 image was taken during a period of flooding while the 2001 image was taken after the flood waters had receded. Visible also in the images, especially in the south-central area of the 2001 image, are extensive ditches and canals that are used in irrigation.

Pico de Fogo
On 2 April 1995, residents on Fogo Island reported a red glow atop Pico de Fogo volcano. It was the beginning of volcanic eruptions that would continue for seven-and-a-half weeks, sending lava across the floor of Cha das Calderiras (Plain of Craters) that eventually covered 4.3 km2 of farmland, destroyed the village of Boca de Fonte, and forced the evacuation of approximately 1 300 residents. Despite the danger, people live in the caldera and raise coffee, wine grapes, fruits, and other crops in the fertile volcanic soils (red arrows). The 1995 eruption on the southwest slope sent lava flowing to the northwest across the main road through the caldera (yellow outline). Studies are ongoing as to the stability of Pico de Fogo.

Powder River Basin
The Powder River basin, located in northeast Wyoming and southeast Montana, is a core area of coal and natural gas production in the United States. Coal mining activities in the basin date back to 1975.
In recent years, surface mining in Wyoming has mushroomed, making it the leading coal producer in America at almost 300 000 tonnes per year. Similarly, coal bed methane gas development in this region is unrivaled in the U.S.
The images show areas under coal exploitation. Notable is the remarkable increase in mining operations in the 2001 image. Reasons for the expansion include improvements in the area's rail network, the high grade of the coal deposits, and the depletion of high-grade deposits in other major coal mining areas such as West Virginia and Kentucky.
The open cast coal mines appear as white-purplish while the reddish brown areas are bare ground. Vegetated areas are green.

Prudhoe Bay
Since the discovery of oil in Prudhoe Bay, Alaska, in 1968, the oil industry has dramatically transformed the former North American Arctic wilderness. Prudhoe Bay and 18 other oil fields currently sprawl over more than 2 600 km² (1 004 square miles) in the region. North Slope oil fields now include 3 893 exploratory and producing wells, 170 production and exploratory drill pads, 800 km (497 miles) of roads, 1 769 km (1 099 miles) of trunk and feeder pipelines, two refineries, several airports, and a collection of production and gas processing facilities, seawater treatment plants, and power plants. These satellite images document the dramatic changes that the Prudhoe Bay region has undergone over the past 35 years.

Punta Europa Oil Facility
Petroleum and natural gas are key to Equatorial Guinea’s rapid development and growing GDP. The Alba gas field located 19 km north of Bioko Island is the country’s largest natural gas field, with 37 000 million m3 of proven reserves. The two images show massive infrastructure development of the gas and the hydrocarbon facility at Punta Europa on Bioko, between 2000 and 2007.
The Punta Europa plant flares natural gas and associated byproducts—initially at a rate of approximately 2.5 million m3 per day to the current volume of about 3.5 million m3. To reduce the economic and environmental damage associated with this flaring, the Atlantic Methanol Production Company completed construction of a methanol plant at Punta Europa in May 2001. The plant consumes around 3.5 million m3 per day of quality gas to produce 19 000 barrels per day of methanol used in a variety of industries. Similarly, Marathon Oil and its partners are nearing completion of a liquefied natural gas plant. These two facilities will eliminate the need to flare gas at Punta Europa. The projected greenhouse gas reduction from the methanol plant alone is 2.85 million metric tonnes of carbon dioxide equivalent per year for each year of the project.

Revane
The impact of drought and over-grazing on the woody vegetation of Senegal's northeastern plateau is evident both on the ground and from space. On the left, one of the earliest satellite photographs ever taken of northern Senegal (Corona, 26 December 1965) shows ancient valleys cutting through gravelly plateaus, with extensive bushland vegetation. In the late 1950s, a borehole was drilled deep into the underlying aquifer at Revane, providing water in the dry season for livestock of the region's semi-nomadic pastoralists, the Fulani. By 1965, the early stages of landscape degradation (bright areas) around Revane are visible, a result of heavy livestock concentrations. By 1999, this badland phenomenon, exacerbated by years of drought, had spread extensively along the shallow valley slopes, leaving barren, unproductive surfaces (smooth, bright patches). A firebreak runs diagonally across the image from Revane to the northeast.

Rondônia
Approximately 30 per cent of the world's tropical forests are found in Brazil. In a continuing effort to decentralize the Brazilian population and exploit undeveloped regions, the Brazilian government constructed the Cuiaba-Port Velho highway through the province of Rondônia. Completed in 1960, the road serves as the access route for infrastructural development in the region, previously occupied solely by indigenous people. In 1975, the region was still relatively pristine, with much of the forest intact. By 1989, the distinctive fishbone pattern of forest exploitation had appeared and by 2001 had expanded dramatically. The highway has become a major transportation route for immigrant farmers seeking income-producing opportunities. Migration into the area continues unabated.

Rosso-Nouakchott Highway
North of the border between Mauritania and Senegal, National Highway 2 connects Mauritania’s coastal capital Nouakchott with the regional capital of Rosso. The highway has brought increased settlement to this arid area, leading to the loss of natural vegetation for building, grazing, and fuel, and beginning the process of desertification. Without vegetation to retain water and decrease wind erosion, the fertility and productivity of the soil declines, dry sandy soil begins to drift, and vegetation is less able to re-establish itself.
The signs of progressive degradation of the land along the Nouakchott–Rosso Highway can be seen in these images. In the 1972 image, bright reflection from the sandy soils surrounding the highway is mixed with some vegetation (shades of green). In the 1990 image, the path of the highway shows as a bright yellow corridor from northwest to southeast through El Haedi. The 2006 image shows the same pattern of vegetation loss along the highway.
Turning off the overlay images and zooming into the bright areas along the route of the highway, one can see areas where the vegetation has been almost completely lost. Continued population growth is increasing the demands made on this arid landscape.

Rutile Mining in Moyamba District
Sierra Leone is mineral rich; titanium minerals such as rutile and ilmenite are its principle mineral exports. Before war erupted in 1991, mining represented 90 per cent of Sierra Leone’s registered exports and roughly 20 per cent of its GDP—rutile accounted for well over half of that. The Moyamba District, which borders the Atlantic Ocean in the west and Bonthe to the south, is the most active rutile mining area in the country. Although mining companies left during the war, they returned when the war ended in 2002.
Rutile is mined by creating large artificial lakes which are then dredged, leaving behind large water-filled pits up to 600 m long. In Sierra Leone, these activities have left vast areas of land deforested and degraded. It is estimated that between 80 000 and 120 000 hectares of land have been mined out in different parts of the country with minimal efforts at restoration.
In the 1974 image, one small mining operation is visible (centre); however, much of the Moyamba District was still covered with relatively intact forests at that time. By 2003, mining activities had replaced large portions of forest with water-filled pits. These mining sites have extremely poor health and sanitary conditions; the pits teem with mosquitoes and bacteria that are linked to a high incidence of malaria, cholera, and diarrhoea.

Rwenzori Glaciers
Uganda, Democratic Republic of the Congo
A comparison of satellite images from 1987 and 2005 shows a decrease in the extent of glaciers on Speke, Stanley, and Baker peaks in the Rwenzori Mountains, which lie on the equator between Uganda and Democratic Republic of the Congo, and are a source of water for lower plains like Kasese. Seasonal changes in snow and ice cover prevent simple visual analysis from conclusively measuring the decline of these glaciers. However, scientific findings from studies in 2003 and 2006 show that the glaciers at the tops of the Rwenzori Mountains are rapidly receding. The glaciers declined by 50 per cent between 1987 and 2003.
This glacial recession is generally attributed to increased air temperature and decreased snow accumulation during the 20th century. It has recently been suggested that decreasing cloud cover during that same time period has contributed to a higher rate of sublimation (vaporisation of ice without melting) of these glaciers as well.
A century ago the glaciers of the Rwenzori Mountains covered nearly 6.5 km2. If the glaciers continue to recede, as they have since 1906, researchers estimate they will be gone in the next 20 years.

Sakhalin
Mixed deciduous and evergreen needle-leaf trees dominate the boreal forests of Sakhalin Island, just off the eastern coast of Russia. The tremendous natural reserves of the boreal forests serve as "carbon sinks" that help to regulate global climate. Boreal forests are also home to a unique collection of plants and animals, including rare and endangered species such as the Amur Tiger. Fire is a natural and often vital component in maintaining the health of boreal forests. But since the 1950s, the frequency of fires has increased on Sakhalin Island as its forests have been subjected to rapid exploitation and disturbance in the acquisition of lumber, oil, coal, and peat. As people moved into the region in greater numbers, the risk of fires started by trains, cars, trash fires, and wood stoves increased greatly. These satellite images show the impact of forest fires on Sakhalin Island.
In 1998, roughly 300 intensely hot fires burned an area nearly the size of Luxembourg. Three people died and nearly 600 were made homeless by a very rapidly moving crown fire that consumed the town of Gorki within a few hours. Pink and red burn scars in the 1999 image very clearly show the extent of the fire damage to the island's forests near the end of that year.

Saloum River Estuary
The mangrove forests of the Saloum-Sine Delta sprawl across roughly 65,000 hectares of the coast of southeastern Senegal. They are made up of a variety of salt tolerant species; from shorter trees forming low canopies to some of the tallest mangrove trees in the world growing up to 40 meters. These forests play an important role in the natural environment and in the lives of local residents, providing important habitat for deer, antelope, hyenas, monkey and other species. They are especially crucial to migrating birds. In addition they also serve as nursery areas for important fish species and shelter for oyster colonies utilized by local communities.
Parc National du Delta du Saloum provides protection to 76,000 hectares of the forests and surrounding areas and 180,000 hectares of the delta are designated as a UNESCO Biosphere Reserve. Nevertheless, since the late 1960s it has been recognized that these forests are dying. They have declined in both area and density by roughly 25 percent since the early 1970s. This is generally attributed to a decline in rainfall over past decades and over-exploitation of water reserves which have changed the mix of salt and fresh water in the estuary making it too saline for many trees. In addition, exploitation of the forests for firewood and lumber and to facilitate oyster harvesting is occurring at an unsustainable rate.
Areas in the satellite images which have changed from dark green to gray between 1972 and 2006, particularly in the northern portions of the delta, show where the mangroves have died off. While there are large areas under protection and reforestation projects, much of the fate of these mangroves will depend on adequate freshwater flow to reduce the salinity to levels that favor the mangroves. A continued long term trend of decreasing rainfall would present an enormous challenge to restoration efforts.

San Francisco
The City and County of San Francisco is the fourth-largest in California and the 14th-largest in the United States, with a 2005 population of 799 263. Roughly three quarters of a million people live within the city proper, with about seven million within the broader metropolitan area, popularly known as San Francisco Bay Area. San Francisco is the second most densely populated major American city, after New York. The city predates the gold rush of 1849, but as a port city on the way to the California gold fields, San Francisco saw explosive population growth after the first discoveries were announced. By 1869, it was connected to the Eastern cities by railroad, and at that time, it was one of the ten largest cities in the United States despite being a full thousand miles or more west of "the frontier." It remains a premier city of the United States.
It is also arguably one of the most beautiful cities in the United States, sitting right on the San Francisco Bay. The city's climate is moderated by its closeness to the Pacific Ocean, and the relative warmth of the Pacific air that flows toward the city over the cold water currents near the coastline is responsible for the city's famous fogs. The city is bounded on the east by the rocky and forested hills of the Coast Range Mountains. The Bay Bridge connects the city with Oakland, and beyond that, to Interstate 80, which runs from San Francisco to New York City through Salt Lake City, Chicago, and other large cities.

Sangaredi Bauxite Mine
The Sangaredi Mine in the Upper Guinea Forest falls within one of the world’s most biologically rich, yet seriously threatened, ecosystems. Recent biological assessment of the area surrounding the bauxite mine and proposed alumina processing facility identified five reptile species, 17 amphibian species, 140 species of birds, 16 species of mammals, and eight primate species, including the endangered West African chimpanzee and western red colobus.
The Sangaredi Mine is Guinea’s largest and most profitable. A proposed alumina refinery, sited approximately 25 km to the west of the mine, is expected to bring a US$3 000 million capital investment, thousands of jobs, and infrastructure development. The consortium which is building the refinery is working with Conservation International to incorporate ecological considerations into the plans. A biological assessment of the area was conducted as a part of that process.
Bauxite mines and alumina refineries typically create serious ecological problems. Bauxite ore is mined in open pits, requiring the removal of vegetation and topsoil. In the 2007 image, the Sangaredi Mine is visible as a vast open pit approximately 20 km from one end to the other. Alumina refining produces highly caustic “red mud” that negatively affects surface and groundwater quality. In addition to direct environmental impacts, the increased population and infrastructure development associated with the mine will likely put immense pressure on this environmental “hotspot.”

Santa Cruz
Santa Cruz is situated in Bolivia's rich, fertile lowlands, a region highly suitable for agriculture. In the 1975 satellite image, the region's forested landscape appears as a dense, essentially unbroken expanse of deep green that extends to the Rio Grande (Guapay) River. By 1986 roads had been built that linked the region to other population centers. As a result, large numbers of people migrated to the area. A large agricultural development effort (the Tierras Baja project) led to widespread deforestation as forests were clear-cut and converted to pastures and cropland. By 2003, almost the entire region had been converted to agricultural lands, including the area east of La Esperanza across the river. In the area north and west of Los Cafes (upper left), notice the grid of squares on the landscape, each with an internal star-shaped pattern. At the center of each square is a small community.

Santiago
Santiago, the capital of Chile, is home to more than one-third of the country's total population of 15 million. Santiago's rapid growth is part of a national trend, but it is also a reflection of the large numbers of immigrants who are moving into the city.
Santiago's population growth has led to a horizontal expansion of the city, principally towards the south and southeast. Chilean urban scholars speak of this expansion as the "urban stain" that continually exceeds and expands the limits of the Metropolitan Region of Santiago (MRS) while incorporating previously rural areas into it. Characteristics of Santiago's urban sprawl are haphazard growth, low-density housing, poor transportation, and air pollution. In the time frame illustrated by these images, Santiago's population has nearly doubled.

São Tomé
São Tomé is the capital city of the island that shares its name. Located in the island’s Agua Grande district, the population of São Tomé increased from a mere 8 431 in 1940 to 51 886 in 2001.
The satellite image shows how settlements, especially along roads, have expanded inland from the city. While much of the island still retained its natural vegetation in 2007, vegetation loss is obvious near the capital city and surrounding settlements, where forests have been converted to croplands. Substantial oil reserves have recently been discovered off the island of São Tomé, which will most likely fuel increased development.

Sapo National Park
Liberia’s Sapo National Park is a largely undisturbed area (161 400 hectares) of lowland rain forest in the Upper Guinean Forest ecosystem. This ecosystem, which stretches from Cameroon to Guinea, has been decimated by logging, mining, and agriculture, leaving just three intact blocks, two of them in Liberia. Created in 1983, Sapo National Park was expanded by over 50 per cent in 2003. It is habitat for vulnerable and endangered species including the western chimpanzee, pigmy hippo, and forest elephant. The park’s relatively pristine condition makes it an invaluable resource to Liberia and the world.
In the 25 years prior to Liberia’s current government, the area of logging concessions granted totaled approximately 2.5 times the entire forested area of the country, with multiple concessions often overlapping one another. Concessions surrounded the area of Sapo National Park. Following a review of legality and status, all of the existing forest concessions were cancelled in February 2006. A year earlier, squatters who were illegally mining and poaching within Sapo were evicted.
The 1974 image shows the intact forest of the Sapo area prior to the park’s creation. While roads and villages appear to have increased in the area surrounding the park, the 2001/2003 image shows that within the park itself, the forest remains in good condition.

Shatt al-Arab
Lining the 193-km-long (120-mile-long) Shatt al-Arab estuary, formed by the confluence of the Tigris and Euphrates Rivers, is the largest date palm forest in the world. Stretching back from the riverbanks towards the desert, date plantations extend for distances varying from a few hundred metres to almost six kilometres (4 miles). In the mid-1970s, the region counted some 17-18 million date palms or a fifth of the world's 90 million palm trees. By 2002, more than 14 million, or 80 per cent, of the palms were wiped out.
Salinisation in the Shatt al-Arab region began emerging in the late 1960s. The situation rapidly deteriorated as dam construction intensified throughout the Tigris-Euphrates basin, considerably reducing freshwater flows and eliminating periodic flooding of the Shatt al-Arab that formerly washed out accumulated salts. In addition, with the outbreak of the Iran - Iraq war in 1980 the palm forest was unavoidably caught in the prolonged and intense crossfire. The destructive power unleashed by modern weapons in ground battles and aerial bombardments as well as deliberate felling reduced the palm forest to an emaciated shadow of what it was in its lustrous past.
The date palms, whose botanical name is Phoenix dactylifera L., are named for the mythical Phoenix bird that sprang from the ashes; date palms are also able to regenerate from fire damage. Biotechnology may be the modern Phoenix that will help replace the millions of palms that have been destroyed along the Shatt al-Arab. Iran is using a new cloning technique to accelerate mass date production, as dates are naturally slow to propagate. Already, thousands of palm plantlets have been introduced. Bio-safety regulations, however, will need to be observed to ensure that the Iran-Iraq treasure grove of 800 plus date varieties, representing more than a quarter of world date diversity, is not jeopardized by a broad dissemination of cloned palms.

Shenzhen
The city of Shenzhen is located just across from Hong Kong and southeast of the Zhujian (Pearl) River Delta Region in China. The city has been the focus of intense urbanization, known as Shenzhen Special Economic Zone (SSEZ). Comparison of these satellite images shows the dramatic change in the landscape from 1979 to 2004, as thousands of high-rise buildings and factories have replaced previous agricultural and vegetated areas. The gray colors in the image depict urban areas, green represents natural vegetation and blue represents water.

Shume Magamba
Shume Magamba forest reserve is located in the West Usambara Mountains. It is one of the thirteen blocks forming the Eastern Arc Mountains of Tanzania and Kenya, along the Albertine Rift. It is comprised of 12 000 ha of moist montane forest, which is a gazetted forest reserve, with 2 500 ha under exotic plantation. The Eastern Arc is one of the most biologically rich regions in the world, with a large number of endemic animal and plant species. It is regarded as one of the world's top 25 global biodiversity hotspots and is increasingly being managed for biodiversity conservation.
The forest is threatened by timber harvesting (pit sawing) and agricultural encroachment. Part of the Shume-Magamba Forest on the West Usambara Mountains was degazetted from a Forest Reserve soon after independence in 1961 and was then converted to agriculture by land-hungry residents. Other major threats to the forests in the West Usambaras include fire spreading from surrounding farmlands and gold mining. In the former case, the enhanced burning regime is believed to have been the main cause of the replacement of Afromontane forests with grassland and scrub-grassland across large areas.
The sharp boundaries at the edges of the forest indicate areas where forest has been converted to farmland. The 2005 image shows these boundaries pushing further into the forest in several places. The high resolution image (see photos panel below) shows detail of the area highlighted by the yellow box in the above images. In addition to crops, areas of forest plantation are displacing natural forest. Areas of trees with parallel lines cut through them are generally tree farms.
Tanzania had the sixth largest annual net loss in forest area between 2000 and 2005 in the world of about 412 000 ha/yr; second largest in Africa after Zambia. In total, between 1990 and 2005, United Republic of Tanzania lost 14.9 per cent of its forest cover. Currently, 39.9 per cent of the country is forested. Apparently, a number of mountains have lost at least 80 per cent of their original forest cover, including Taita, Ukaguru, Mahenge, and West Usambara.
The energy economy in Tanzania is largely focused on collecting, distributing, and consuming wood fuels (wood and charcoal) to satisfy household demands for cooking. As much as 90 per cent of all primary energy consumed in Tanzania is biomass based.

Sidi Toui National Park
The semi-arid grassland and scrub of southern Tunisia has been profoundly altered by human activities during the last century. Located on the northern fringe of the Sahara Desert, this ecosystem is susceptible to erosion and desertification brought on by droughts, overgrazing, and agriculture. In 1993, Sidi Toui National Park was established. Within the bounds of this protected area, natural vegetation began to return. The 1987 image shows the barren condition of the region before the park was created. In the 2006, image the outline of the park, which is protected from the effects of grazing cattle, contrasts markedly with the surrounding landscape. Protection substantially increased the vegetation density and species diversity, particularly of the grasses.
The Scimitar-horned oryx (Oryx dammah) and five other species of gazelles and antelope native to this area had been brought to near extinction by lack of habitat and overhunting throughout the 20th century. Classified as critically endangered in 1996, a small population of Scimitar-horned oryx was introduced into Sidi Toui Park in 1999. If the population inside the park thrives, it may enable future reintroductions of Scimitar-horned oryx elsewhere, Sidi Toui also provides habitat for several native species of antelope, as well as a variety of bird species.

Souss-Massa Valley
The Souss-Massa Valley is located in southwestern Morocco. Rainfall in the valley is only about 200 mm per year, which is not enough to support most types of agriculture. In 1968, Morocco’s King initiated a plan to irrigate one million hectares. In 1972, the Youssef Ben Tachfine Dam was built on the Massa River, creating a reservoir that supported a substantial growth in agriculture in the valley and allowed development of a modern agricultural area of 18 000 hectares, primarily dedicated to vegetable and citrus cultivation.
Irrigated agriculture in the valley also uses groundwater; however, groundwater withdrawal has exceeded the natural rate of recharge. Since the 1970s groundwater resources have declined, forcing farmers to drill much deeper wells to reach water.
In the 1970s, greenhouse agriculture was introduced to the area. It requires 80 per cent less water per kg of crop than unprotected agriculture. The 1988 satellite image shows a few greenhouses (light blue squares) scattered throughout the valley. The 2003 image shows the expansion that has occurred in greenhouse agriculture, with greenhouses (white squares) covering a substantial portion of the valley’s agricultural land.
The Souss-Massa Valley is Morocco’s leading region for greenhouse agriculture, covering 14 530 hectares in 2004. Vegetables are the primary crops, with tomatoes covering more than half the greenhouse area.

Sudd Swamp
The Sudd is a vast wetland ecosystem in southern Sudan where the Nile River meanders for nearly 645 km through the landscape. During the dry season (February 2005 image), the wetlands contract to approximately 8 300 km2 of permanent swamp. During the wet season (July 2005 image), the Sudd floods, expand to cover 80 000 km2. This annual pattern of water rising and receding shapes the entire ecosystem and is crucial to the survival of the wetlands’ plants and animals and to the nomadic lifestyle of the Nuer, Dinka, and Shilluk people who live in the region.
The Jonglei Canal project (yellow arrows), begun in 1978, was designed to speed the movement of Nile water around the Sudd wetlands, reducing evaporation and making more water available downstream. Despite the possible downstream benefits, the proposed 360-km canal could have a devastating effect on the wetlands of the Sudd. Recent studies also show that the project could impact the regions’s climate, groundwater recharging, and water quality as well.
Construction of the canal stopped in 1983 because of armed conflicts in the area during the second Sudanese civil war. This conflict has now ended and plans to resume the canal’s construction are being evaluated. Efforts to preserve the wetlands received a major boost in 2006 when the Sudd was added to the Ramsar List of Wetlands of International Importance.

Sundarban
Sundarban, the largest mangrove forest of the world, is situated in the southwestern part of Bangladesh and in the West Bengal state of India. Guarded by the Bay of Bengal, Sundarban is an excellent example of the coexistence of human and terrestrial plant and animal life. Despite high population pressure and environmental hazards such as siltation, cyclone flooding and sea level rise, the areal extent of the mangrove forest has not changed significantly in the last 25 years. In fact, with improved management, the tiger population has increased from a mere 350 in 1993 to 500-700 in 2000. Ecotourism is increasing as well. However, while sufficient data is not available, several reports suggest that forest degradation has been occurring in many parts of Sundarban. The Sundarban mangrove forests are also becoming more vulnerable due to the significant rise of shrimp farming in the region. The increase of shrimp farming has negatively affected agriculture and also contributed to the loss of mangrove forests during the past two decades.

Swaziland Sugar Plantations
Sugar cane production has become Swaziland’s biggest industry as large-scale producers have been joined by hundreds of small-scale farmers. Much of this growth can be attributed to government promotion of sugar cane farming. While this growth has come at the expense of natural flora and fauna, it has brought significant benefits for the eastern province of Lubombo.
Sugar cane plantations are found primarily in northeastern Swaziland where temperatures are optimal. However, this region is also characterized by erratic rainfall with periods of drought; precipitation provides only 25 per cent of the water sugar cane crops need. To meet the sugar cane industry’s remaining water requirements, several dams have been constructed along major rivers, including the Sand River and Mnjoli Dams. These satellite images, from 1979 and 2006, show the dams and how the area devoted to sugar cane plantations has increased over time.
Sugar cane exports bring in roughly US$1 500 million annually to Swaziland. Lubombo Province, in particular, relies heavily on income from sugar cane as well as social services that the industry provides, including medical care, education, housing, and access to clean water. Yet fluctuating sugar prices have prompted the Swazi government to promote the production of other crops. Such a transition, however, is far easier for small-scale farmers than for large-scale producers with extensive plantations.

Sydney
Australia is the sixth largest country in the world. It is roughly the same size as the conterminous United States and 50 per cent larger than Europe. Yet Australia has the lowest population density of any country in the world. With 4 million inhabitants, Sydney is Australia's largest city. It is also the capital of New South Wales, the country's most densely populated state. Sydney is bounded by the Pacific Ocean to the east, national parks and deep-water inlets to the north and south, and the spectacular Blue Mountains far to the west. These natural boundaries have influenced Sydney's urban growth patterns. Over the past several decades, the city's expansion has been largely westward toward the Blue Mountains, as can be seen in these two satellite images. As suburbs sprawl into bushland, they become vulnerable to summer bush fires.

Tahoua Province
A band across the southern third of Niger receives enough rain (250-750 mm) to sustain most of the country’s rain-fed agriculture and pastoralism. This stretch of semi-arid Sahel is also where most of Niger’s rapidly growing population lives. However, the Sahelian climate is quite variable and in this ecologically frail region this poses serious problems for traditional livelihoods.
In recent decades, Niger’s climate and its demographic problems have negatively impacted its agricultural land by forcing agriculture onto land that had been historically used for livestock— land receiving less than 350 mm of rain per year. This intense pressure on fragile lands led to acute environmental degradation (1975 image).
More recently, a combination of various projects and farmer initiatives has led to significant revitalization of the land in large part by the planting and protection of trees. Farmers no longer clear tree saplings from their fields before planting crops. Instead they protect and nurture the trees, carefully plowing around them when sowing millet, sorghum, peanuts, and beans. A recent study revealed 10 to 20 times the number of trees across three of Niger’s southern provinces than there were in the 1970s (2005 image). This transformation of the land has reduced drought vulnerability and will help people diversify their livelihoods so as not to rely solely on rain-fed crops.

Taï National Park
Taï National Park, N’Zo Partial Faunal Reserve, and the Goin-Débé and Cavally Forest Reserves, are remnants of tropical rain forests that at one time stretched from Ghana to Sierra Leone. Taï National Park, the most pristine and heavily protected of these, contains some 1 300 plant species, over half of which are unique to the region’s rain forests. Taï is also home to most of the large mammals that occur in the area, including the leopard (Panthera pardus), which is critically endangered.
The park was declared a forest and wildlife refuge in 1926 and more recently a National Park, a UNESCO Biosphere Reserve, and a World Heritage Site. This area was historically remote and sparsely populated; however, roads built in the late 1960s brought periods of population influx. That population has converted most of the forest outside the protected areas to agricultural land, leaving only scattered fragments of forest. Much of this deforestation had already occurred before these images were taken; however several further areas of forest loss can be seen between 1988 and 2002 (yellow arrows).
While deforestation continues outside the protected areas, the Government of Côte d’Ivoire has maintained the Taï National Park’s integrity and its core area remains in relatively good condition. The current concern within the park is commercial poaching, putting at risk all fauna, but duikers and primates in particular. Also, as these images make clear, the boundaries of the park are under increasing pressure from a growing population that is running out of unprotected land to farm.

Tensas River
The Tensas River Basin watershed lies in eastern Louisiana and covers 272 000 hectares (672 126 acres) in the Mississippi River Alluvial Plain. Historically, 90 per cent of this land was forested. Roughly 85 per cent of the forests were cleared during the 1960s and 1970s for the planting of soybeans. Clearing of the forest has exacerbated flooding problems and increased erosion.
As this pair of images reveals, intensive agricultural development has continued in the Tensas River Basin over time. Croplands appear in shades of tan; forests are green. The only remaining large tracts of hardwood forests in the watershed are in isolated wildlife refuges and management areas. Small forest remnants also occur on some private lands. The contrast between the amount of land cover change that has occurred on opposite sides of the Mississippi River in these images is striking. In the state of Mississippi, the forests remain largely intact, possibly due to the absence of lands suitable for cultivation.

The Black Triangle
The so-called Black Triangle is an area bordered by Germany, Poland, and the Czech Republic and is the site of extensive surface coal mining operations. In the 1975 satellite image, the gray areas are surface mines located primarily in the Czech Republic. Airborne pollutants from coal extraction activities tended to become trapped by the mountainous terrain to the northeast and were concentrated in the area around the mines, eventually causing severe deforestation along the border between the Czech Republic and Germany. In the 2000 image, this deforestation is very obvious, appearing as large brownish patches. Interestingly, the 2000 image also reveals somewhat improved vegetation cover - a slight "greening" of the landscape - as compared to conditions in 1975. Some of this improvement may be attributable to actions taken by the three countries bordering the Black Triangle to reduce pollutants produced by the mining operations. The implementation of anti-pollution technologies, including circulating fluidized bed-boilers, clean coal technology, and nitrous oxide emission burners, appears to have reversed some, albeit not all, of the environmental damage experienced by the region as a result of the mines.

Thon Buri
As the city of Bangkok, Thailand, has grown, the need to provide food and an additional economic base for its burgeoning population has been a primary concern. Parts of the Thai coastline, including those near Bangkok, offer conditions favorable to aquaculture, especially shrimp aquaculture. Over time, as these satellite images from 1978 and 2002 reveal, the mangroves that once lined the coast near Bangkok, as well as the rice paddies that lay further inland, have been replaced by aquaculture ponds (blue patches inland) and urban structures (light purple). The promotion and development of aquaculture has led to the current situation, where farmed shrimp and fish production now exceeds that of shrimp and fish capture by traditional methods. The development of this coastal industry has raised environmental concerns, as extensive areas of mangroves have been destroyed to make way for aquaculture ponds. The challenge of balancing the needs of people living in coastal areas versus the welfare of the coastal areas themselves is ongoing, and repeated along many coastlines worldwide.

Three Gorges Dam
The Three Gorges Dam on the Chang Jiang (Yangtze) River in China is one of the largest single construction projects ever attempted on the planet. The dam was constructed to supply approximately one-ninth of China's electricity- as much power as could be generated by at least fifteen nuclear power plants. It is a relatively environmentally clean option compared to coal burning or nuclear power plants. It is also hoped that the dam will help control flooding on a river where seasonal floods during the past century have caused the deaths of over one million people. However, the Three Gorges Dam project has also had negative environmental and social impacts as a result of the massive construction efforts and the submergence of land along the river above the dam. The former village of Zigui (top center of image) has already been submerged.
The 1987 image shows the nature of the river and surrounding landscape before work on the dam was begun. In the May 2004 image, the enormous Three Gorges Dam is clearly visible, as is the reservoir of impounded river water that has been created behind it.

Torreón
The city of Torreón is located in the State of Coahuila in central Mexico. Founded in 1893, Torreón is a modern industrial city that is home to flour mills, textile plants, iron foundries, a rubber factory, and various other industries. Torreón is also situated in a rich agrarian region noted for its cotton and wheat farms and cattle ranches.
Since the 1970s, however, there has been a significant decrease in cropland in the Torreón region due to drought and subsequent extraction of ground water from aquifers. In 1992, the Mexican government passed the Federal Water Law, in which the government sought to shift responsibility for some water management rights issues from federal to local governments, or even individuals. This left farmers in a position to negotiate their own water rights. At the same time, however, prices of water for irrigation were also raised. The amount of land around Torreón on which crops are raised continues to decrease.

Toshka Project
In the mid 1990s, water levels in Lake Nasser on the Nile River approached the reservoir’s storage capacity of 183 m above sea level. Excess water was released through a spillway, which flowed into the Toshka Depression in the Western Desert. Over the next several years, continued overflow created a series of lakes on some of Egypt’s most arid land. After peaking in 1998, reservoir levels declined and flow through the spillway stopped in 2001. Since that time, water levels in the Toshka Lakes have been declining as well, primarily by evaporation and to a lesser degree by infiltration.
In January 1997, the Egyptian government began construction on a network of canals to continue carrying Lake Nasser water to Toshka with the goal of irrigating 3 360 km2 of land in the Western Desert. The project, called the New Valley Project, is intended to relieve overcrowding within the densely populated Nile Valley and provide economic development.
The project is an enormous undertaking with a cost over US$1 000 million. Critics of the project are concerned that the anticipated withdrawal of 5 000 million m3 of water per year will reduce water available to farmers on the delta, leave Egypt more economically vulnerable to drought, and reduce resources available for other development opportunities. Much of the needed infrastructure is already in place and crops are already being produced on irrigated land including fruits and wheat (green around the lakes, 2007 image).

Tripoli
Tripoli, the capital city of Libyan Arab Jamahiriya, is located on the country’s Mediterranean coast along a narrow band of fertile lowlands that quickly give way to a vast interior of arid, rocky plains and seas of sand. Tripoli has undergone steady urban growth over the past thirty years. These satellite images, from 1976 and 2006, document some of the major changes in urban extent and the intensification of agriculture in the area surrounding the city.
Urban areas appear as shades of grey. Darker patches south of the city, visible in the 1976 image, represent grasslands that have since been converted to agricultural fields. Bright green areas are planted croplands. A few small areas of natural vegetation remain.
Before the Great Man-Made River (GMMR) project began supplying water to the Tripoli area, the city’s demands on the coastal Upper Aquifer were raising concerns of unsustainable use leading to salinisation of coastal water resources. The GMMR project began supplying water to Tripoli in August 1996 and is continuing to expand its delivery across the country’s coastal area.

Valdivian
Chile has been recently considered as one of the most economically competitive countries in Latin America. Rapid growth in Chile's production and export of forest products is based on the expansion and management of exotic species forest plantations in the last 30 years. However, some studies have demonstrated that such expansion of forest plantations has produced a decrease in native forests in the south-central region of the country. These two Landsat, MSS and ETM scenes taken in 1975 and 2001, respectively, show changes in land use during the last 30 years. Many endangered tree and shrub species have been affected by this change, which has also led to a dramatic reduction of landscape diversity as well as goods and services from forestlands. The traditional landuse practices of small-scale logging of native forests, livestock and agriculture have been replaced by large-scale timber production that puts endemic endangered tree and shrub species at risk.

Velingara
Located in southern Senegal is a feature that appears to be a meteor-impact-generated structure, possibly millions of years old. It is a circular, multiple ring structure with an overall diameter of 48 km (30 miles) and centered about 12 km (7 miles) south-southwest of the town of Velingara.
The high rim structure of the Velingara Crater encloses the Anambe Basin. Water previously flowing out the south end of the basin was harnessed behind a dam in the mid-1970s as a source of irrigation for rice and other crops. The 1975 image predates the irrigation development. By 2001 intense agricultural systems had appeared near the center of the crater(right image), contrasting sharply with the swampy areas (dark green) nearby. The Velingara Crater was first detected using Landsat data in the early 1970s.

Virunga National Park
Uganda, Rwanda, Democratic Republic of the Congo
The Virunga Park area is home to over half of the world’s 700 surviving mountain gorillas (Gorilla beringei beringei). In an area approximately 40 km by 12 km with an elevation ranging from 2 300 to 4 507 metres there are a variety of ideal gorilla habitats including bamboo and montane forests.
The area includes Mgahinga National Park in Uganda, Volcanoes National Park in Rwanda and the Mikeno (Gorilla) sector of Virunga National Park in DRC. Surrounding these protected areas, however, are some of the densest human populations in Africa. In addition to population pressure, armed conflict in the region has made habitat and species protection very difficult.
In the 1978 image, a line between the protected areas and the populated agricultural areas surrounding the parks is already apparent. While the boundary of the parks has remained largely intact since the mid-1970s, during the 1990s and early 2000s, large numbers of people moved into the area surrounding the parks, many of them refugees from armed conflict. A report by the Institut Congolais pour la Conservation de la Nature documented a large coordinated influx of people from outside the area in May and June of 2004. The report estimated that 15 km2 of land at the west edge of the Park were deforested during this time. The decline in areas of green outside the protected areas suggests that few fallow fields and little natural vegetation remain—a sign of the agricultural intensity in this area.

W National Park
“W” National Park in Burkina Faso is part of the W-Arly-Pendjari Complex, a transboundary network of protected areas, which, taken together, are the largest and most important continuum of ecosystems in the West African savannah. The complex’s varied habitat is home to approximately 544 different plant species, 360 bird species, and more than 50 species of mammals including elephants and hippopotamuses.
Partial eradication of the black and tsetse flies (carriers of river blindness and sleeping sickness), an influx of transhumant pastoralists due to Sahelian droughts, and government promotion of cotton growing, led to a regional population explosion in the late 1970s. Nevertheless, human population in and around the Park remains relatively low, which, along with its protected status, has kept it the most pristine of Burkina Faso’s protected areas.
In the early 1970s image, the boundary of the Park and surrounding protected areas is indistinguishable from adjacent lands. By 2005, areas of contrasting land use are easily visible, as is the Kompienga Reservoir. Built in 1989, the dam is a source of water for irrigated agriculture as well as a fishery. Also visible in the 2005 image are scattered burn scars (dark reddish purple patches) as the dry season begins. Burning across most of the area is an annual occurrence.

Walvis Bay
Walvis Bay is an economic and environmental hotspot in Namibia. It has been designated as a free-trade area and placed on the Ramsar List of Wetlands of International Importance. The Walvis Bay lagoon, the largest area of shallow, sheltered water on the Namibian coast, supports a wide range of birdlife. Walvis Bay’s tidal channels, mudflats, and sandbanks support roughly 150 000 birds, including the African black oystercatcher, lesser and greater flamingo, chestnut banded plover, and black-necked grebe.
Walvis Bay’s solar evaporation facilities process 24 million metric tonnes of seawater each year, producing more than 400 000 metric tonnes of high-quality salt. The solar evaporation process occurs in a series of connected ponds through which seawater flows, evaporates, and deposits salt in crystallizing ponds. In 1973, the salt evaporation ponds were still relatively small (red and blue rectangles in the centre of the image). By 2005, however, they had grown to cover 3 500 hectares in the lagoon.
Most of the energy required to extract salt from seawater comes simply from sunlight and salt produced by this method is 99.7 per cent pure. About one-third of worldwide salt production uses this method, which, when properly managed, is very environmentally friendly.

Wassa West District
With the encouragement and support of the World Bank, Ghana revised its mining laws in the 1980s, privatising the industry and liberalising regulation. This resulted in several hundreds of millions of dollars of foreign investments in Ghana’s mining industry. While this brought gold production to new highs, replacing cocoa as Ghana’s most valuable commodity, it also resulted in social and environmental impacts that are proving to be unpopular locally and internationally.
Over 60 per cent of the Wassa West District in western Ghana is now under concession to large-scale gold mining companies, the greatest concentration of mining in a single district in Africa. The large footprints of these open-pit mines directly result in significant forest loss. In addition, related infrastructure and associated population growth indirectly drive even greater land cover conversion. Significant portions of Wassa West’s tropical rainforest have been degraded by or lost to this gold mining boom since the 1980s.
The mines in Wassa West have so far been kept out of the forest reserves, which can be seen as dark green areas with clear straight boundaries in both the 1986 and 2002 images. However, the 2002 image shows that the footprints of mining operations in the district have grown dramatically since 1986.

Weipa Bauxite Mine
Mining of bauxite (aluminum ore) began at Weipa, on the Cape York Peninsula in Queensland, Australia, in 1963. The mine produces 8.5 metric tonnes of ore annually, making it one of the world's largest open-cut bauxite mines.
Under current mining practices, vegetation is cleared and the topsoil is removed and either stockpiled for later use or immediately used to replace topsoil on previously mined areas. After topsoil removal, the bauxite is removed, resulting in a lowering of the entire landscape to a depth equivalent to the thickness of the orebody, often several meters. If the topsoil can be returned to a mined-out area after only a short time, it still contains most of the original soil fungi, bacteria and micro fauna. In addition, the seeds from the original plant community are likely to be viable. On slopes, rigorous soil conservation measures are implemented, and the area is then normally planted with suitable native species so that it gradually reverts to bushland. Some of the profits generated by the mining operation are being placed in a trust for cultural protection, development and long-term investments to compensate for the disruption of local Aboriginal inhabitants and their environment.
The total lease covers an area of approximately 2 590 km² (1 000 square miles) of which 68 km² (26 square miles) have been mined. Approximately 4 km² (1.5 square miles) of the mined land is re-vegetated each year, and over 50 km² (19 square miles) of land has been re-vegetated to date.

Wyperfeld National Park
Wyperfeld National Park in Australia's southeastern state of Victoria consists of some 3 000 km² (1 158 square miles) of dry, native scrubland - classic Australian "bush." Wyperfeld lies in the flood plain of the Murray River, sandwiched between wet, coastal forests and the country's arid interior. The park has water only when the river overflows its banks. Much of the park's vegetation is mallee, a type of shrubland dominated by several sparse, tall varieties of eucalyptus. Over 450 species of plants, 200 species of birds, and a variety of mammals and reptiles live within the park.
Fires set by people have been used to maintain the Australian bush for thousands of years. Fires also occur naturally and occur in the park and surrounding area nearly every year, leaving huge fire scars on the landscape that are easily seen in satellite images (light green areas). Remote sensing is used to document the extent of burn areas, and to help land managers plan controlled burns that help maintain the native vegetation and habitat for native wildlife. Wyperfeld staff currently set fuel-reduction fires along the park's edges but fight all accidental fires.

Yala Swamp
Yala Swamp is located in western Kenya, on the northeastern shore of Lake Victoria. It is the third-largest wetland ecosystem in the country, after Lorian Swamp and the Tana River Delta. The swamp provides a habitat for many plants and animals, some of which are extinct in the larger lake ecosystem and others that are endemic to the swamp.
Nutrient rich sediments deposited by the Yala River and the availability of water makes Yala Swamp particularly attractive for agriculture, including the intensive production of rice, cotton, and various other irrigated cash crops.
The development of this area has pitted the Kenyan government and private investors against conservationists. While the government and the investors argue that a well-planned exploitation of part of this area can help alleviate hunger and poverty in the region, conservationists feel that the Yala Swamp is too important of an ecosystem to be disturbed for any economic gains.
These two images show the area before and after development of the region began. The small farm parcels in the 2002 image have largely been replaced by larger parcels, as is evident in the 2007 image. A dam has also been erected on the river, to provide water for irrigation.

Yamba Berté Forest Reserve
The Yamba Berté Forest Reserve in southwestern Chad is made up of critical gallery forests, pristine woodlands, and a network of small lakes and swamps. The dense forest includes trees that can grow as tall as 35 m. The reserve is important habitat for gazelles, monkeys, warthogs, giraffe, elephants, and the rare giant eland (Taurotragus derbianus).
Yamba Berté is located in a zone of savannah woodland that stretches across southern Chad and also supports a dense human population and most of the country’s agriculture. The introduction of cotton in the 1930s and draft animals in the 1950s supported a large increase in agriculture. During the drought years (1968, 1972-1973, 1983-1984) large numbers of people migrated to the area because of its higher rainfall and the economic opportunity of its larger cities. In addition to subsistence crops such as maize, millet, and sorghum, the area is ideal for growing cotton and groundnuts, which are the two primary cash crops.
The 1986 image shows agriculture around Yamba Berté, including some encroachment on the reserve area. The second image, captured 15 years later, shows dramatically increased agriculture around the reserve and several areas where the reserve boundary has been breeched.