Regional groundwater drought mapping for sustainable management.

Groundwater is one of India's most important natural resources. Overexploitation of groundwater takes place during the period of scarcity and droughts in order to meet the irrigation demand and other requirements. Classifying the region according to the risk level is the first step in a process to bring groundwater to a sustainable level of management. The Palar Basin located in Tami Nadu State, India, is selected as the study area. Thirty years of groundwater level data from 80 observation wells located within the basin are used for the analysis. A statistical method developed by Herbst is used to estimate groundwater drought intensity during dry periods. The drought risk index was estimated for each well and a groundwater risk area map was generated using GIS. This map will be useful for decision making in pursuit of sustainable development and management of groundwater.