Research On Flood Control Operation Of Reservoir Based On Flood Forecast

During the period of flood season, the majority of reservoirs in our country operate under fixed flood control levels at present, and some under different flood control levels by stages. In order to get the most benefits from reservoir, flood of different frequencies should be controlled under different flood control levels by use of forecast information, which is available in reservoir operation. After reading lots of relevant research results, author uses the principle of reservoir operation and risk benefit analysis to research different flood control levels of Wangkuai reservoir based on different forecast information, which can provide a scientific way for pre-store and pre-discharge based on forecast. The main content and results in this paper are:(1) As one of large reservoirs in Daqinghe valley, Wangkuai reservoir's the precision of forecast system, which is available, has reached the first class. So, in order to get more comprehensive benefits from the reservoir, it's necessary to make pre-store and pre-discharge based on forecast.(2) Since flood control level is decided based on the flood of little frequency, it's necessary for a small flood to make pre-store based on forecast so as to utilize flood enough. The model of flood loss and benefit, which includes the loss at reservoir area and downstream area and the benefit on the water supply and power generation, has been proposed to demonstrate the best scheme. The optimum flood control level of Wangkuai reservoir is 193.5 meter when flood occurred once less than 10 years was predicted.(3) Schemes of pre-discharge based on forecast are shaped on the ground of predictable time of rainfall, the time of runoff and the limited flux of Wangkuai reservoir. Indexes system has been used in the assessment of schemes of pre-discharge based on forecast. With the forecast information of Wangkuai reservoir, index probable values of different schemes are calculated by Monte-Carlo simulation. Then, a comprehensive fuzzy model of assessment is established to demonstrate the optimum schemes. As a result, the optimum schemes are 24 h/800 m3/s, 48 h/400 m3/s and 60 h/200 m3/s for predictable flood occurred once 20 years, and for predictable flood occurred once 50 years, the counterparts are 36 h/600 m3/s, 48 h/400 m3/s and 36 h/400 m3/s.