Application of analytical hierarchy process, frequency ratio, and certainty factor models for groundwater potential mapping using GIS

The main goal of this study was to investigate the analytical hierarchy process (AHP), frequency ratio (FR), and certainty factor (CF) models for groundwater potential mapping using geographical information system (GIS) at Varamin Plain, Tehran province, Iran. In the first step, the groundwater conditioning factors such as altitude, slope angle, slope aspect, topographic witness index, rainfall, drainage density, water table level, aquifer thickness, lithology, and distance from rivers were prepared. The groundwater yield dataset was prepared using earlier reports, and extensive field surveys. In total, 71 groundwater data with high potential yield values of ≥40 m³/h were collected and mapped in GIS. Out these, 50 (70 %) cases were randomly selected for models training, and the remaining 21 (30 %) cases were used for the validation purposes. Subsequently, groundwater potential maps were produced using AHP, FR, and CF models in ArcGIS 10.2. Finally, the receiver operating characteristic (ROC) curves for all the groundwater potential models were constructed and the areas under the curves (AUC) were computed. From the analysis, it is seen that the FR model (AUC = 77.55 %) performs better than AHP (AUC = 73.47 %) and CF (AUC = 65.08 %) models. The results of groundwater potential map can be helpful for future planning in groundwater resource management and land use planning.