Site Selection Modeling for Artificial Recharge in Kashan Aquifer Using Statistical Methods, AHP and Groundwater Environmental Considerations

Management of groundwater resources, especially in arid and semi-arid areas, has great importance. Natural and anthropogenic phenomena in recent decades have caused critical conditions and fall in groundwater table. In such situations artificial recharge of groundwater is amongst the most important management strategies. Purpose of this study is the use of AHP and statistical methods (fuzzy-statistical ranking and parameters optimization of artificial recharge model based on nonlinear regression and sensitivity analysis) to determine suitable areas of artificial groundwater recharge in Kashan aquifer. In this study, SMAGR artificial recharge model was used for site selection artificial recharge in Kashan aquifer based on seven parameters of groundwater contamination (GC), soil infiltration rate (IR), capability of hydraulic conductivity (HC), soil pollution (SP), land use (LU), topographic slope (TS), and water table (WT). Adding layer of aquifer pollution risk was also used for site selection of suitable areas based on considerations of groundwater environmental conditions. The information layers were prepared in GIS environment and the fuzzy-statistical rating was combined based on geometric mean with equal weights. In addition, removal sensitivity analysis was used to determine the effective weight of parameters and to optimize the model. Based on the results obtained from statistical method and optimized model about 15% and 0.1% of the western and southern parts of aquifer are suitable to very suitable for artificial recharge. Also the sensitivity of the model showed a decreasing trend associated to different parameters of removed groundwater contamination, soil infiltration rate, hydraulic conductivity, soil pollution, land use, topographic slope and water table with effective weights of 2.96, 2.83, 2.41, 2.33, 2.21, 2.07 and 1.89, respectively.