Delineation of Groundwater Potential Zones in a Tropical River Basin Using Geospatial Techniques and Analytical Hierarchy Process

Abstract

The need for sustainable groundwater resource management increases with demand of clean water across the planet for industrial, agriculture, and domestic uses. In the present study, an attempt has been made to delineate the groundwater potential zones (GWPZ) in a tropical river basin, viz. Achankovil river basin (ARB), using GIS and analytical hierarchy process (AHP) techniques. For this, a total of eight geo-environmental variables such as lithology, geomorphic features, land use/land cover, soil texture, lineament density, drainage density, topographic wetness index, and mean annual rainfall were used to identify the GWPZ, and limited number dug well yield data published by the Central Ground Water Board (CGWB) is used to validate the model. The result indicates that nearly 50% of the basin is characterized by good to very good groundwater potential, whereas poor GWPZ accounts nearly 25% of the basin. Among the different thematic factors’ geology, geomorphic features and slope angle have significant control over the occurrence of groundwater in the study area. The linear relation between well yield data and groundwater potential zones is assessed, and a R2 value of 0.790 indicates that the predicted model is trustworthy and can be used for groundwater resources management in the study area. The integrated approach used in the study is reliable and can be replicated anywhere in the tropical region.