Coupled modeling of groundwater-surface water interaction for water abstraction management in the Zayandeh Rud river basin

Optimal operation of water resource systems requires understanding the interaction between the surface water and groundwater in the region of interest. This research focuses on linking the FEFLOW modeling with a coupled Mike ۱۱ model in Zayandeh Rud basin in Iran. In this basin, the excessive extraction of groundwater in the past has caused a severe drop in the groundwater level and intensified the penetration of surface water into the groundwater. Since the interaction between surface and groundwater is a complex issue, groundwater modeling was therefore taken into consideration. The aim of the groundwater model is to describe the volume of surface water leakage caused by groundwater extraction in the area of Zayandeh Rud River. The results showed that the model could predict groundwater level and its variations in comparison to the observed values. The calibrated and validated model was then used to set up different scenarios to analyze the impact of decreasing groundwater extraction of legal wells in the basin. In a scenario defined for the irrigation networks of Nekouabad left and right in downstream of the dam, reduction of the groundwater extraction by ۴۰% showed a great impact on the simulated groundwater level in the basin. However, this reduction does lead to a decrease in the return flow from irrigation fields due to less water available for irrigation purposes. As part of any research project, many limitations have been documented in the research, such as the quality of data (e.g. hydrological input data) and the quantity of data (WWTP). Suggestions have been made for the long simulation period of the coupled model to assure practicality in the scenario analysis.

Keywords:

groundwater modelling , groundwater management , scenario definition , FEFLOW , Mike۱۱