Assessment of groundwater and surface water interaction using mathematical model for Bogra district

Abstract

Groundwater and surface water play an important role in meeting the water demands. Domestic & irrigation water needs are being met in many parts of the world using groundwater. Depending on the hydrological conditions, the river aquifer interaction plays a significant role in the availability of water resources in an area. In this study the interaction process of the aquifer with the three main rivers of Bogra district is investigated. The study to understand the features of river-aquifer flow exchange has been conducted using MIKE 11 and MIKE-SHE modelling software which incorporates main features of the entire hydrological process as well as the river-aquifer flow exchange. The study area has been selected considering extensive use of GW and perennial flow of the rivers, thus an area for river Jamuna (39.5km), Bangali (83km) and Karatoya (73km) has been selected. All required data, particularly information on land and water use, aquifer properties, river-aquifer conductance etc. have been collected from available secondary sources. The model has been simulated within the period from 2005 to 2016. For the two rivers under the prevailing hydrological and water use condition, the inflow (flow from river to aquifer) period is higher than outflow period except Bangali river where the outflow period is higher than inflow period. In case of Karatoya river the inflow period is very high compared to the outflow period due to low groundwater level. For the options; Option-1 (25% reduction of flow) and Option-2 (50% reduction of flow), the inflow period decreases and outflow period increases. The inflow rate is higher compared to the outflow rate for the two rivers except Bangali river for base condition. Under the options the inflow rate decreases for all rivers for reduction of upstream flow. Jamuna river inflow has decreased to 45% for Option-2 (50% reduction of flow) and for Karatoya river inflow has decreased to 53% for Option-2 compared to base condition. The outflow rate under all options also increases for all rivers except Jamuna. The increase rate is high of 80% for Option-2 compared to base condition in case of Karatoya river which will affect the aquifer.