River Aquifer Interaction Modeling for the Waterlogged Aquifer and Sustainable Groundwater Irrigation along River Flood Plain

The river aquifer interaction model was developed for the waterlogged-alluvial aquifer to address the issues of the lower river leakage and higher aquifer discharge in the waterlogged groundwater system. The developed model was simulated and calibrated for the 15 years simulation period (2006-2020). From the model study, it is observed that river aquifer interaction changes seasonally, river leakages to the aquifer in the monsoon period and aquifer discharges to the river in the rest period. From the analysis, it is visualized that the monthly variation in river aquifer interaction majorly depends on the river stage. From the analysis, it also concluded that the value of river leakage is low as compared to aquifer discharge caused due to aquifer waterlogging. The model was further applied to reduce the waterlogged area to a certain degree by introducing sustainable groundwater irrigation from the waterlogged aquifer during the dry/Rabi season. Thus, the fraction of uncultivated land near the river flood plain converted as agricultural land. Sustainability is achieved by considering the three scenarios to unaltering the river aquifer interaction seasonally. The three scenarios are introducing groundwater irrigation to convert (i) 25%, (ii) 50% and (iii) 75% of the uncultivated land to agricultural land. It is revealed from the study that the sustainable proposed scenario is where the agricultural land equals to 75% of uncultivated land. The proposed methodology' has been illustrated in the alluvial flood plain of the Barak river in Cachar, Assam, India.