Numerical analysis of a deltaic aquifer system for sustainable management of groundwater

Abstract

In recent years, groundwater simulation models have emerged as a preferred tool of water resources managers for addressing questions about the impacts of groundwater development and the effects of human activities on ground water. The present study refers to the development of a groundwater flow simulation model along with sensitivity and scenario analysis for a deltaic aquifer in Eastern India using finite difference-based numerical model named Visual MODFLOW. The study area is a river island located in the Mahanadi delta of Odisha and is surrounded by Kathajodi River and its branch Surua. Calibration and then validation of the flow model was performed satisfactorily with a mean r value of 0.958, mean RMSE value of 0.632 and mean NSE value of 0.914. The sensitivity analysis of the model showed that groundwater level was more sensitive to river stage followed by recharge and hydraulic conductivity whereas it was least sensitive to changes in specific storage. Using the calibrated and validated numerical model, scenario analyses were done to study the aquifer response to different stress conditions. The scenario analysis indicated that there will be no significant change in the groundwater level of the study area even after 15 years of pumping at the present rate under existing conditions. The developed model can serve as an effective tool for developing strategies for sustainable water management under changing climatic and socio-economic conditions.