Locating of Suitable Area of Pumping Drinking Water Using FAHP Method (Case Study: Birjand Aquifer)

Groundwater quality deterioration which originates from excessive pumping caused motivation of the identification of suitable area for groundwater harvesting. In this study, eight quality parameters e.g. Na, Ca, Mg, SO4, TDS, EC, CL and NO3 of Schuler standard along with water level drawdown and water transmissivity coefficient (T) were considered as decision criteria and were calculated using Analytical Hierarchy Process (AHP) method. Then raster data layers of criteria were prepared in GIS tools fuzzified using fuzzy membership function and criteria fuzzy layers decision were created by overlaying of fuzzy raster layers of criteria. As main goal of the paper, final layer of suitable area of water drinking harvest was categorized in five class containing poor, average, fairly good, good and very good levels. The results showed that 2.24, 28.08, 27.86, 28.17 and 13.63 percent of the aquifer area respectively are placed in the mentioned classes. Also a comparison was carried out between modeling results and drinking water wells in the aquifer. Results showed that the eastern parts of the plain have favorable conditions for water drinking exploitation.