GIS Based Geo Hazard Assessment of Pakistan for Future Urban Development Using AHP

Abstract

Pakistan is subject to frequent earthquakes which are often severe (especially in north and west) and severe flooding along the Indus after heavy monsoon rains (July and August). Losses to life and property remained very high in the recent past. In order to mitigate the losses there is a requirement of integrated decision support which could help planners to take complex decisions accurately and quickly. The study aimed at providing multi criteria decision analysis framework resulting into regionalization of the territory of Pakistan according to the level of vulnerability to these natural disasters. Site suitability for urban development in Pakistan was assessed by the application of GIS and analytical hierarchy process (AHP). GIS can effectively store, retrieve, manipulate, analyze and display the spatial in site selection problems. AHP can be used to calculate weights of criteria while decision maker remains consistent in judging and allocating comparative preference to criteria. Weights of criteria were calculated and aggregated in two clusters namely environmental (elevation, slope, aspect, distance from rivers, land surface temperature and precipitation) and hazard (flood extents, Earthquake density and intensity). The results of two clusters were then synthesized to obtain suitability index map. Indices in the map were classified into four categories representing extremely suitable, suitable, less suitable and worst regions for urban development. This studies shows how an effective multi criteria decision support method can be developed to select suitable sites for urban development using GIS and AHP. Urban development should be planned in extremely suitable areas.