Demarcation of Groundwater Prospective Zones in Humid Tropical River Basin: A Geospatial Approach

Groundwater, being a vital resource, needs to be developed with proper understanding about its occurrence in time and space. Unscientific sand mining is a dominant environmental issue in this humid tropical river basin namely Bharathapuzha river basin geographically on central part of Kerala state, southwest part of India. The sandy layers along the river course declines its water holding capacity due to indiscriminate sand mining throughout the river basin. For a sustainable development of water resources, it is imperative to make a quantitative estimation of the available water resources. The purpose of the study is to identify the groundwater potential zones in the Bharathapuzha river basin in Kerala state, India based on Remote Sensing and GIS technology. Thematic layers considered in the study are geomorphology, land use, and lineament derived from IRS P6 LISS IV digital data; drainage network contour and slope maps are generated using toposheets; geology from GSI geology maps, with the help of Arc GIS Software and Erdas Software. Storativity and transmissivity of the study area was prepared using pumping test data. The thematic layers were over layered by weighted overlay method using Arc GIS. Four groundwater potential zones were identified in the study area represented as very good, good, moderate and poor potential zones.