Modeling Artificial Groundwater Nourishing (through Flood Spreading) Site Selection Processbased on GIS Technique and AHP Method(Case Study: Khoy Plain Aquifer)

A comprehensive model based on AHP and GIS is developed to locate areas susceptible to artificial groundwater nourishing through flood spreading. Khoy plain, which in recent years has increased its groundwater usage, selected as the case study. Sixteen criteria considered including slope, land-use, geomorphology, geology, distance from fault zones, roads, waterways, wells, springs and aqueducts, rate of rainfall, temperature, and evapotranspiration, electrical conductivity of available groundwater, and its hydraulic gradient, thickness of non-saturated alluvial section, ability of aquifer transfer, and surface permeability of soil. Above-mentioned attributes were classified into four groups, i.e. physical, climatic, hydrological and hydro-geological clusters. Gathered data were prepared in GIS environment, and based on pair wise comparisons, the preference of each cluster and its sub-criteria was determined. By combination of the layers using Weighted Sum method in ArcGIS, unacceptable zones ignored, and the remaining ones were classified into five categories. Finally six scenarios were proposed in very suitable zones. The proposed scenarios were then prioritized based on developed model and the 3rd scenario was selected. Results indicated that due to the similarity of the climatic and hydrological characteristics of selected sites in the non-wide areas, the final decision will have a small effect on these indicators.