Scale issues

Scale is a description of the way data can be quantified (Lewis, 1995). Map scale is defined as 'the ratio of length on a map to length on the ground' (Aspinall, 1995). Scale was also defined by Forman and Godron (1986) as ' the level of spatial resolution perceived or considered'. Scale is therefore the unit of observation.

Scale problems associated with the use of GIS

GIS has the ability to combine data from maps of different source scales and can output data at any scale. Therefore, caution is needed to avoid producing output at scales the original source data was not intended to be viewed at.

Reading 2.1 Goodchild, M.F. and Quattrochi, D.A. ' Scale, multiscaling, remote sensing and GIS. The importance of scale'