Assessment of groundwater level fluctuations in and around Ranchi district, Jharkhand using geospatial datasets and methods

Groundwater is a precious resource, particularly in places that are dependent on rain-fed rivers. Mapping and visualizing the fluctuation of the water table surface is thus an important exercise that shows the overall recharge and extraction induced changes in its form. This can help identify places where over-exploitation of the groundwater is occurring. This small study examines the fluctuation of the depth to water table parameter in Ranchi district in eastern India, based on readings from a large number of stations distributed throughout the district. These trends are mapped for each location and GIS methods are used to visualize the fluctuations in detail. 3D mapping of the withdrawal versus recharge zones are done, together with some estimations of the volume of groundwater change over the examined period. Pockets of over-use of this precious resource are succinctly identified. The simple methods presented here can also be applied to other locations for analysis and display of such datasets.