Detecting Appropriate Groundwater-Level Trends for Safe Groundwater Development

Computation of long-term linear trends of pre- and post-monsoon groundwater (GW) levels is important for the periodic categorization of regions in India according to their GW safety. For this purpose, a specific procedure has been recommended by the Groundwater Estimation Committee, 1997 (GEC'97), constituted by the Government of India. The present article points out the limitations of this procedure by providing statistical evidence from the long-term dataset in the case of Maharashtra. An improved method, having the same data requirements as the GEC'97 method and based on statistically significant recent linear trends is proposed as an alternative. Its suitability for administrative actions is demonstrated on the Maharashtra dataset. We specifically note the spatial patterns in recent linear trends obtained from our algorithm, which are otherwise difficult to detect.