Study on the Effects of Water Supply and Flushing Sediments through Reservoir Operational Rules

• Main Authors: Kao, Lih-Shan, 高力山
• Other Authors: Fi-John Chang
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/37739052577490165519

碩士 === 國立臺灣大學 === 農業工程學系研究所 === 86 === Recently, the development of water resource is an urgent task for the government due to the stong water demands in Taiwan. One of the effective methods to store surface water is to build a dam and form a reservoir. However, there will be many difficulties in building a dam such as lack of suitable dam sites, high cost of dam construction, related environmental impacts. On the other hand, reservoir sedimentation problems are serious in Taiwan because of the high sediment supply from its watershed. Therefore, to restore and sustain the useful lift of the reservoir is the most important issue for reservoir operation and management. To achieve the goal of preserving long-term reservoir capacity, the feasibility of flushing sediments through a reservoir will be investigated in this study. Based on the water supply and the water usage to flushing operations, the operational rules of reservoir is adjusted and evaluated. Genetic algorithms employed in operational simulation model is used to optimize the reservoir operational rules. The sediment flushing model is established to estimate outflow sediment discharge. The sediments flushing model consists of the water surface profile calculation and bed elevation calculation. Meanwhile, the outflow sediment discharge calculated is used to construct the updated line for the reservoir operators when flushing operations are performed. reservoir elevation-storage curve. The operational simulation model is then combined with the flushing sediment model for simulating operational rule curve which is optimized by the genetic algorithm. From the simulated results based on the shortage index (SI), it is found that the best flushing sediment timing is in May or in June every year. The operational rule obtained by the model can be a guideline for the reservoir operators when flushing operations are performed.