احسان پورحسن

Effectiveness and proper spatial distribution of catchment management measures to achieve the desired level of water quality standards is of particular importance. In line with the purpose of this research, the development of a framework to provide the characteristics and optimal location of the best management measures (BMP) and the development of pollution load allocation plan at the catchment area has been pursued. For this purpose, a simulation-optimization approach in the form of SWAT-MOPSO was developed with the aim of reducing the costs of implementation and operation of BMP and pointsource pollutants and reducing the phosphorus load in the catchment area of Seymareh Dam. In this regard, the SWAT model was calibrated and validated based on data from 2002 to 2018 for flow, sediment, total nitrogen and total phosphorus data. The results of the calibration process were eva‎luated by statistical indices of correlation coefficient (R2) and Nash-Sutcliffe coefficient (NS) in 9 hydrometric stations of the study area. In most stations, these statistical indices were more than 0.6, which indicates the good performance of the SWAT model simulation in the desired period. The best management practice and pollutant load allocation were defined in four scenarios: 1- Reducing the use of fertilizers and pesticides, 2- Implementing plant filter strips, 3- Implementing water retention ponds and 4- Purifying point pollution loads ,in critical sub-basins. BMPs techniques, point source pollutants included in the pollution load allocation program, and critical sub-basins based on the results and sensitivity analysis of multiple point and non-point load management options were nominated in the SWAT model. The simulation-optimization approach developed in this research provided several optimal options in the form of BMPs and phosphorous pollution load allocation program to planners and managers. Analysis of the results presented in the Pareto front shows that in the best economic option and the best option for improving the quality of water resources, the amount of phosphorus pollution will be reduced by 38.4% and 63%, respectively, compared to the current scenario. The economic costs corresponding to these option were 505.66 and 4691.15 million dollars, respectively. In the best economic option from the Pareto front, plant filter strips were selected by the optimization algorithm due to their lower cost and greater effectiveness in critical sub-basin affected by this technique. Also, due to the lower cost of wastewater treatment compared to other pointsource pollutants, Kermanshah municipal wastewater and aquaculture of Islamabad were presented in the optimal pollution load allocation program in the optimal economic option of Pareto front by the optimization algorithm. The scenario of full implementation of BMPs and allocation of pollution load with maximum selective capacities reduces the phosphorus pollution load by only 0.57% compared to the most favorable water resources quality conditions fromt the Pareto front, while increasing the economic cost of implementing resource management programs at the basin level by 10.6% .

بهترين اقدامات مديريتي , الگوريتم بهينه‌سازي چندهدفه , تغذيه گرايي , مديريت حوضه آبريز , كيفيت آب , تخصيص بار آلودگي

Best management practice , Multi-objective optimization algorithm , Eutrophication , Basin management , Water quality , Waste load allocation

Ehsan Pourhasan

Dr. Motahareh Saadatpour