Representation of the environmental quality profile of a metropolitan area

The spatially and temporally varying environmental quality of a metropolitan area is described by means of empirically derived environmental indices. The approach is based on the principles of benefit analysis and consists of a number of logical steps including the selection, the measurement and determination of the spatial distribution, and the normalization (scaling) of the selected environmental indicators. To derive composite indices, the normalized indicators are weighted, based on the Delphi technique and subsequently aggregated. The results are given by means of isopleths, including single and composite index isopleths plotted by computer on common maps.World Health Organization