Résumé
In most parts of India, and particularly in South India, groundwater levels are hazardously declining, which entails drought and inherent water-quality problems. The need of the hour is to adapt the exploitation of groundwater to its availability. To find sustainable solutions, it is indispensable that the policy makers be equipped with suitable predictive tools to better guide their future actions. The Indo-French Centre for Groundwater Research (NGRI, Hyderabad) has developed a decision support tool (DST) designed for groundwater scenarios under variable agro-climatic conditions, which focuses on the impact of changing cropping pattern and artificial recharge on groundwater levels. DST is based on the well-known water table fluctuation method, a well-adapted method in the hard-rock and semi-arid context. The method has been implemented in a small pilot watershed (53 sq. km, Maheshwaram, Ranga Reddy District, Andhra Pradesh, India), a representative South Indian catchment in terms of geology, overexploitation of aquifers, climate (semi-arid), cropping pattern, rural socio-economic context, etc. The results show that if no solution is found quickly, groundwater decline will entail the loss of about 50% of the pumping borewells by around 2010, with all the accompanying serious socio-economic consequences. However, even if the groundwater situation follows a slippery slope, DST foresees some sustainable solutions. DST is placed between the policy makers, experts (for calibration and model validation) and the endusers, i.e. farmers. DST has been developed under an Excel software interface, which makes it a user-friendly single tool for all those involved in groundwater management.