Multiobjective Optimization For Reservoirs Operation Incorporating Interbasin Water Transfer In Korea

Although the philosophy and methodology toward sustainable water resources management have been consistently progressed, it is still significant but controversial issue for the society and ecosystem. Currently the circumstance and situation pursuing water resources development and utilization is getting even worse due to global climate change, temporal and spatial imbalance of water resources distribution, social consciousness for the conservation of environment and ecology and conflicts among many stakeholders.Andong, Imha and Youngcheon reservoir which are located in central eastern part of Korea and Nakdong river system, have undertaken important roles for their own region, however their basins, water supply system, inflow trends vary. To supply additional water into Hyungsan river basin and Keumho river basin, the water from Imha is being transferred to Youngchen reservoir. And for securing the water resources which was spilled during flood season, Andong and Imha reservoir tunnel to transfer the water bidirectionally is recently completed.In the context of three reservoirs connected and interbasin water transfer, this paper focuses on optimal water allocation strategy, sensitivity analysis corresponding inflow homogeneity and evaluating performance of water transfer system.Statistically analyzed historical inflow series of each reservoir, and identified inflow homogeneity between reservoirs employing several measures, carried goodness of fit test of various probability distributions for inflow data, and generated the inflow scenario using Monte Carlo simulation method based on aforementioned analysis.Established multiobjective optimization model for conjunctive and multipurpose reservoir operation, especially took bidirectional and gravitationalwater transferinto consideration as a constraint.It adopted GAMS software and nonlinear programming as a solver.Solved the optimization problem adopting weighted sum method and nondimensionalization for converting various single objectives to one multiobjective problem,described non-inferior solutions and Pareto frontier between conflicting objectives for better decision making. Proposed optimal reservoir operation and conveyancescheduling scheme, and analyzed the outcomes depending on varied inflow homogeneity scenarios. Finally, quantitatively appraised the effects of water transfer network in terms of contributing to net benefit and reliability of water resources management.It is expected that these water transfer measure enable three reservoirs to have its distinctive system, and facilitate their storage to transfer another reservoirs, enhance the benefit and efficiency regarding water resources utilization.