Multi-criteria decision analysis for delineation of groundwater potential zones in a tropical river basin using remote sensing, GIS and analytical hierarchy process (AHP)

Abstract

The present study emphasizes the effectiveness of the integration of remote sensing, GIS and analytical hierarchy process (AHP) techniques in groundwater management, specifically in the delineation of the groundwater potential zones (GWPZs). In this study, various geoenvironmental factors, such as lithology, geomorphology, land use/land cover, the density of lineaments and stream network, slope, and soil texture are used to identify the GWPZs and to classify the spatially distributed groundwater potential of the Manimala River Basin (MRB) - a tropical river basin of the southern Western Ghats (Kerala State, India). A multi-criteria decision analysis (MCDA) is performed in ArcGIS, using the weights of different themes generated by the AHP technique, for the delineation of the GWPZs of the basin. The results indicate that nearly 50% of the basin area (mostly across the highlands and the midlands physiographic zones of the basin) is characterized by moderate to poor groundwater potential, whereas the very good potential zones extend across 20% of the basin area. Among the different geoenvironmental factors, lithology, lineament density and geomorphology have decisive roles in the occurrence of groundwater of the basin. Validation of the delineation of the GWPZs of the basin using the groundwater yield data of a limited number of dug wells underscores the efficiency of the integrated approach as well as the suitability of the geoenvironmental factors (used in the study) for the identification of the groundwater potential of the region.