Eco-hydrologic stability zonation of dams and power plants using the combined models of SMCE and CEQUALW2

Construction of dams has a significant impact on hydrological conditions of rivers. Eco-hydrology, as a sub-discipline of hydrology, focusses on ecological processes occurring within the hydrological cycle and strives to utilize them for enhancing the environmental sustainability. The aim of this study was to determine the stable and instable eco-hydrologic regions in the study area. First, the factors affecting the eco-hydrologic stability were selected according to field surveys. Afterwards, the layers related to each factor were prepared in geographic information system (GIS) and ArcGIS 10 software. These factors were also weighted using the analytic hierarchy process and pairwise comparisons. Ultimately, the final map was prepared by integrating and determining the homogenous units. The CEQUALW2 software, as a water quality and hydrodynamic model, was used to confirm the accuracy of the quality data and to perform the water quality simulation in the studied dam. According to the results, pollutant source and water quality were found to be the most important factors. The final map indicated that most of the areas had not a suitable condition in terms of stability at the downstream reaches.