Assessing spatio-temporal variations of groundwater level in the Damodar River basin, India using MODFLOW

The global demand for groundwater is expected to increase due to changing hydrological and population patterns. Hence, spatio-temporal characterization of groundwater is crucial for its sustainable management options. This study introduces a fully distributed groundwater simulation model, based on the MODFLOW framework, to understand the fluctuations in the groundwater table and basin-scale hydrological dynamics of the Damodar River basin (DRB) in India. Monthly simulations were conducted over a 5-year period (2015–2020) to quantify changes in groundwater head and interactions between the river aquifer and the watershed. Real field abstraction data were used to represent pumping components of water use in the MODFLOW model. Parameter Estimation Test (PEST) based calibration and validation were performed to estimate the unknown hydraulic conductivity and recharge. The model outcomes reasonably align with heads at the observation wells, thereby improving our understanding of the water table in large river basins. The findings highlight the influence of monsoon precipitation and the overall changes observed in DRB. Furthermore, the study combined the tributary stream network and PEST-calibrated recharge, which further enhanced the physical representation and accuracy of the model despite the additional data requirements. Decline in groundwater level was observed, which potentially highlights unsustainable water management practices in the river basin. The results underscore the significance of numerical groundwater models, which are crucial for informed decision-making in robust groundwater planning interventions.

 

Keywords: Groundwater, MODFLOW, PEST, recharge, river basin