محمد فاریابی

The river and groundwater are significant components of hydrological cycle, and the interaction between these two water resources attracted a great attention recently. Over the years, several methods have been used for the study of the water exchanges between these resources. In this research, a combined approach including hydraulic head measurements, hydrochemistry, and water balance calculations is applied to the assessment of the river–aquifer interactions. The study area is located in the north part of the Dezful–Andimeshk district in the southwest of Iran. The Dez River is the major surface water body that interacts with groundwater in this area. The Dez dam has been constructed on this river in the northern part of the study area. In this study, a series of water measurements including river water stages and discharge monitoring at Dez dam site and Dezful hydrometric station, groundwater table measurement in the piezometric network, and chemical analysis of river and groundwater were carried out for the evaluation of river–aquifer interaction. In order to monitor river and groundwater in the study area, a monitoring network including a hydrometric station (near the Dezful city), 38 piezometers, and 23 water quality monitoring wells have been established by the KhuzestanWater and Power Authority (KWPA). Data of the monitoring network were used for the evaluation of temporal variation of river and groundwater interaction in this research. The discharge measurements of the Dez dam site and Dezful hydrometric station in a 47-year period (1964–2011) shows that the water volume is decreased between these two stations. In addition, examining the time series of river stage and groundwater fluctuations in the study area shows that the groundwater table and river water stage variations have similar patterns. This similar pattern is an observant indication of groundwater and surface water interactions that is confirmed by the interpretation of groundwater potentiometric