Demarcation of Prospective Groundwater Recharge Zones in Hard Rock Area from Southern India

In semi-arid regions, particularly in hard rock areas (Southern India), shallow aquifers are a major source of potable groundwater. These aquifers are indiscriminately exploited to meet the growing demand of water for domestic, irrigation as well as industrial uses. In order to achieve sustainable development, it is essential not only to delineate the groundwater potential zones but also suitable augmentation schemes which, in turn, require delineation of feasible recharge zones. Such zones are conventionally delineated through the application of various indirect methods, such as geological, hydro-geomorphological, geophysical, ¹⁴C-age dating, tracer, entropy method, and groundwater modeling. These methods are, in general, time consuming and may not be economical in the developing countries. A simple, efficient and cost-effective based on cross-correlation method, which takes into consideration the shallow aquifer response to rainfall, is presented to delineate groundwater recharge zones in hard rock areas. The zones so delineated were compared with the results obtained from remote sensing (RS) and GIS techniques and were further validated with the aid of estimated recharge values calculated using the modified water-table fluctuation (WTF) method