Application of the Statistical Index Model in Groundwater Potential Mapping in the Khorramabad Plain

Both the population growth and the growing trend of industrialization have increased water demand in various fields. Therefore, nowadays groundwater resources are one of the most valuable water supply resources. This study aims at mapping the potential areas for groundwater resources in Khorramabad, Lorestan using the statistical index (SI) method. To achieve this, first the existed 212 wells with a yield greater than 11 L/s were randomly divided into two groups of training (70%) and validation (30%) wells. Afterward, the digital layers of the influencing groundwater potential factors (altitude, slope angle, slope aspect, plane curvature, topographic wetness index (TWI), land use, soil, geology, distance from rivers, drainage density, fault distance and fault density) were generated using ArcGIS 10.2 software. Then, the groundwater potential map of the study area was produced using the statistical index method in four potential zones namely low, moderate, high, and very high classes. Finally, assessment of the accuracy of the generated map was performed using the ROC curve (AUC) method. The Result showed the accuracy of the generated groundwater susceptibility map for the study area is 82%, which indicates the high accuracy of this method in the mapping of groundwater potential zones in the study area.