Delineating the Groundwater Potential Zone in Tirunelveli Taluk, South Tamil Nadu, India, Using Remote Sensing, Geographical Information System (GIS) and Analytic Hierarchy Process (AHP) Techniques

Abstract

The water present in the subsurface is considered as a high treasured water source. The present study deals with the delineation of groundwater potential zone in Tirunelveli Taluk, Tamil Nadu, South India. The study area lies between longitude 77°32′16″ to 77°48′8″E and latitude 8°40′12″ to 8°56′34″N with an area of 558.42 km2. The groundwater potential zone of the Tirunelveli Taluk was inferred by the following layers, namely geology, geomorphology, lineament density, drainage density, rainfall, slope, soil and land use/land cover. These layers are digitized with the scale of 1:50,000 in GIS environment from the spatial data sources such as SOI topographic maps, GSI geology map, LANDSAT 8 satellite image, SRTM DEM, Tamil Nadu Agricultural Department daily rainfall data and available existing maps. The weights of the feature layers and ranking of each feature classes arrive from the pairwise comparison techniques of AHP technique. The prepared thematic maps are reclassified based on the influence of the layers feature classes on the groundwater availability. Finally, the reclassified layers are overlaid using weighted overlay tool to prepare groundwater prospect map. The finally this study resulted that 5.76 km2 of the study area is identified as very high groundwater potential. The high potential area covers 382.9 km2, and medium potential zone covers 169.72 km2.