Groundwater modeling to simulate groundwater levels due to interlinking of rivers in Varada river basin, India

Using a two-dimensional Gelarkin finite element model, the present study characterizes groundwater flow in a Varada basin, a semi humid area of Karnataka, India. The model characterization involved taking field data by conducting pump tests describing an aquifer system. Geological geometry and the number of aquifers have been analyzed based on a large amount of geological, hydrogeological and topographical data. The aquifer properties are then transformed into input variables that the model code uses to solve governing equations of flow. The results of the field experiments showed that Varada basin is predominantly confined aquifer. For calibrating the numerical groundwater model, the groundwater flow was simulated in steady state. Results of study demonstrate a moderately high correlation between the observed and simulated groundwater level. In addition, the groundwater level and trend in the transient state has also been elucidated. The validated numerical groundwater model was used to predict the groundwater levels due to impact of recharge from the interlinking of rivers in the basin. The model result provides an excellent visual representation of groundwater levels, presenting resource managers and decision makers with a clear understanding of the nature of the interaction of groundwater levels with the proposed interlinking project. Results build a base for further analysis under different future scenarios for implementation.