Application of Geoinformatics for the Delineation of Groundwater Prospects Zones- A Case Study for Melattur Grama Panchayat in Kerala, India☆

Abstract Delineation of groundwater prospect zones has been carried out using RS and GIS for Melattur Grama Panchayat in Malappuram district of Kerala. The spatial and non spatial database on various terrain features were generated using RS imageries, SOI toposheets, etc. Groundwater prospect zones were delineated through the integration of the reclassified raster map layers of geomorphology, slope percent, drainage buffer, geology, landuse/land cover and soil texture using the weighted overlay analysis in Arc-GIS. The groundwater prospects in the study area were grouped into five classes and their distribution are; ‘very good/ excellent’ (2.49%), ‘good’ (29.72%), ‘moderate’ (47.09%), ‘poor’ (13.64%) and ‘very poor/nil’ (0.47%). The result shows that the groundwater prospect ‘very good/ excellent’ is confined to only 2.49% of the study area, falls in valleys close to the higher order perennial streams. Major portion of the study area falls in the category ‘moderate’ followed by ‘good’. The study results have been verified with field data, the pre monsoon thickness of water column in wells. The overlay analysis of the spatial map of the pre monsoon thickness of water column in wells on groundwater prospect map shows a positive correlation, i.e. the pre monsoon thickness of water column in wells is found to be high in groundwater prospect zones ‘very good/excellent and good’, whereas it is very minimal or nil in ‘poor and very poor’ zones. The Groundwater prospect map of Melattur Grama Panchayat will be served as a base for further exploration using geophysical methods to locate potential well sites for the implementation of rural water supply schemes.