Groundwater Potential of a Fastly Urbanizing Watershed in Kerala, India: A Geospatial Approach

The 6th order watershed, which hosts Thiruvananthapuram, the capitol city of Kerala State, India, has been studied in terms of groundwater potential, employing Geospatial Technologies. The watershed receives an average annual rainfall of 2600 mm. Geologically, the major part of the watershed is characterized by Khondalites, Charnockites and Migmatites of Archaean age, and the remaining by Tertiary sedimentaries, Miocene and Holocene formations. All these rocks are extensively lateritised. Geomorphology, geology, drainage, fracture systems in hard rocks and the slope of the terrain play a significant role on the accumulation and movement of groundwater in the watershed. The integration of these datasets has been accomplished through Geospatial technology. The basin area has been categorised into four zones, namely, Very high, High, Moderate and Low in terms of groundwater potential. It is estimated that about 35% of the watershed, comes under the very high to high category in terms of groundwater potential and is confined to the less inhabited upstream reaches. Low groundwater potential category dominates in the watershed which covers 40% of the area characterized by Built up Area, evidently due to the urbanization.