Management of an aquifer with an emphasis on the interaction of the aquifer and river using MODFLOW model in Gotvand-Aghili plain, Khuzestan, Iran

In recent years, mathematical models are used as efficient tools in the study and management of water resources. Quantitative perception of groundwater flow and knowing the interaction between surface water and groundwater are among the important parameters in water resources management. In this regard, the quantitative model of Gotvand-Aghili Plain groundwater located in Khuzestan Province, in the southwestern part of Iran, has been prepared due to its importance in the agriculture of the region. This study aims to simulate groundwater flow in Gotvand-Aghili Plain using the MODFLOW model to the management of the aquifer and investigates the relationship between the river and aquifer by the Zone Budget method. After the steady-state simulation, the model was calibrated from October 2007 to September 2008 in the unsteady state. After validation of the model, it was used as a management tool to study the different management scenarios and interactions of aquifer-river including the rise and decline of the river water level. The results showed that the riverbank in the north and south of the region is suitable for construction of new wells. The Karun River reach in the study area was divided into seven zones and water balance was assessed in each of them. Results indicate that the river is draining the aquifer in the northern and especially central parts of the plain and recharging it in the southern zones. Aquifer-river exchanges are mostly affected by the river water level fluctuations.