Determine of ground water recharge potential zones by using integrated AHP-GIS method (Case Study of SEMNAN Township)

A large amount of spatial information and criteria is required to determine zones with groundwater recharge potential. The objective of this research is an application of integrated AHP-GIS approach for determination of groundwater recharge potential. Therefore, thematic layers in the field of slope, distance from drainage, soil order, climate, land cover, land use, lithology and distance from fault have been used. The thematic layers have been prepared in ArcGIS9.3 environment. The AHP method has been used to weigh the criteria and indices being investigated. The factors have been carefully analyzed and integrated so that the groundwater recharge potential map of the study area is prepared. Maps of selected thematic layers have been integrated according to Raster Calculator function, in ArcGIS environment. By integrating rated maps with resulting weights in AHP procedure, the study area has been divided into inadequate, intermediate and adequate classifications. The results show that all the selected recharge sites are significantly appropriate from the scientific and applied point of view; thus using GIS and AHP weighting method present a desirable performance in determining zones with groundwater recharge potential. Also, the lithology theme has been determined as the most efficient factor.