مهندسی عمران شریف (Aug 2021)
Multi-Objective Optimization of Operation of Water Resources Systems for Supplying Demands of Aquatic Ecosystems
Abstract
Irregular withdrawals from water resources, unprincipled agriculture at the upstream of Shadegan wetland, and the drainage of agricultural drains and municipal effluents have severely reduced the quality of water entering the wetland. Also, the construction of the Marun and Jarreh dams on the rivers supplying the wetland demand has led to severe hydrological changes in the river and eventually, its environmental demands have not been met in some years. Common water resources operation methods focus on maximizing socio-economic benefits and pay little attention to meeting ecosystem demands. The aim of this paper is to investigate the performance of meta-exploratory algorithms in planning and proper allocation management to resource and uses at the upstream of Shadegan Wetland and the determination of the ecosystem demand of the downstream so that in addition to maximizing the percentage of the basin demand supply during the operation period, this algorithm attempts to reduce the salinity of the inflow to Shadegan Wetland. Due to the importance of the wetland as a seasonal habitat for birds and also one of the important tourist attractions and the importance of protecting its ecosystem, the development of a quantitative-qualitative optimization model for optimal use of available water resources is the purpose of this study. Initially, based on current conditions, the prepared model entitled "reference scenario" is developed for a future 30-year period (2021 to 2050). To achieve the best system response in terms of qualitative and quantitative criteria, the efficiencies of the MOICA and MOPSO algorithms as the optimal scenario are compared. The results indicate that the MOICA algorithm has a better performance in supplying various demands as well as decreasing the salinity of the inflow to Shadegan Wetland more than the MOPSO. With the implementation of the optimal solution obtained by the MOICA, in addition to supplying demands with high reliability in the whole system, the amount of river salinity at the entrance to Shadegan Wetland, especially in low water months, is reduced by about 55%. The coupling model proposed in this research is applicable for other study areas with a quantitative-qualitative operation approach and is able to calculate the environmental demands of the river as well as the downstream ecosystem by taking into account all uses.
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