Comparative Analysis of Ground Water Potentiality Zone using Fuzzy-AHP and Frequency Ratio Techniques

Abstract

The growing population and inadequate water supply is one of the major issues of groundwater resource management in urban areas. In order to tackle such issues, it is necessary to provide adequate information to guide the future urban planning. The study emphasizes on identification of groundwater potential zone (GWPZ) in Guwahati Municipal Corporation (GMC) area. For this purpose, nine conditioning factors namely land use/land cover (LULC), temperature wetness index (TWI), slope, soil, geomorphology, lithology, lineament density, drainage density, and rainfall were taken into consideration to prepare and reclassify using ArcGIS mapping tool and processed in Fuzzy analytical hierarchy process (FAHP) and frequency ratio and (FR) statistical methods. GWPZ map is generated based on two models and randomly selecting 503 wells. The samples were divided into training (70%) and testing (30%) datasets to prepare ROC curves and to assess the accuracy of the two methods. The finding indicates that the training data outcome of FAHP methods (AUC=0.727), FR methods (AUC=0.845) and the testing data AUC using FAHP(AUC=0.730) and FR (AUC=0.821) respectively. The validation result shows that AUC of FR models performed better than FAHP model, thus result appeared to be satisfactory, which means, the zone determined on the map being the relative groundwater potential zone. GWPZ map prepared through this method can be useful to GMC for comprehensive evaluation of groundwater exploration, development, and water resource management for future planning.