Chapter 12 - Assessing groundwater potential zone of Ong river basin using geospatial technology

Abstract

Groundwater is one of the major sources to cater to the domestic and irrigation needs of the majority of the population. However, the overexploitation of groundwater resources and varying climatic conditions have badly impacted the groundwater table across the country over the years. The present study aims to delineate the groundwater potential zone (GWPZ) of the Ong river sub-basin using a multi-criteria decision analysis (MCDA) and analytical hierarchy process (AHP)-based approach. The satellite data derived thematic layers on land use land cover (LULC), topography, rainfall, surface water, and lineament density were integrated with other thematic layers such as geomorphology, geology, soil, and lithology in a geographic information system (GIS) environment. The relative importance of the various proxy layers was estimated using AHP which was used in MCDA. The maximum weight was assigned to the surface water followed by geomorphology and lineament density and the least weight to LULC. Only ∼13.91% area consists of good and very good GWP zones mostly observed in the northern and eastern parts of the study area. The majority of the sub-basin falls under the moderate GWP zone which consists ∼41% of the total area followed by the poor ∼25.59% and very poor ∼19.44% zones. The GWPZ map was validated with groundwater level data accessed for 31 dug wells. The outcome of the study provides baseline information to support better decision making for sustained utilization of water resources in the Ong sub-basin.