Simulation and Assessment of management practices for reduction of nutrients discharge to the Zrebar Lake using SWAT model

In recent years, eutrophication is one of the main challenges in many water bodies, especially lakes and reservoirs. Zrebar Lake as a freshwater lakes in the country that is facing severe eutrophication problem. The main goal of this study is to find solutions to enhance the water quality using integrated simulation approach. For this purpose, Soil and Water Assessment Tool (SWAT) is used as a water resources and agricultural systems simulation model As well as interaction of lake Basin with the changes in lake water quality and quantity. In this study, the impact of the various management practices (BPMs) in critical areas in terms of how to influence them in improving water quality, yield crops and economic costs of their implementation were evaluated and finally the optimal solutions were selected using TOPSIS multi-criteria decision-making method. The results showed that, the filter strip, pollution control emissions in upstream (Qezelchesoo channel) and reduce fertilizer consumption up to 25%, respectively are the best management options in the basin.