Research On Flood Season Staging And Adjustment Of Limited Water Level On Longtan Reservoir

On the basis of longtan valley storm floods seasonal change rule, the theme of this paper are reasonable division of the flood seasonal phases and adjustment of staged limited water level of Longtan reservoir. Feasibility and necessity of flood season staging, reasonable division of flood season, obtaining of the stage design flood, adjustment of staged limited water level, stage risk and benefit analysis are researched. Make the reservoir scheduling operation meet flood characteristics of Longtan valley. On the premise of not increase the risk of flood control, limited water level is selected reasonablly and scientificly, and water storage is timely increased in order to realize the flood resources utilization and remission of the contradictions of during dry water shortages.Staring form the definition of flood season in this paper, the flood season of Longtan reservoir are detennined.Rainfall and runoff indicators are adopted, the flood season staging of Longtan reservoir are calculated by fractal analysis method. The last based on demanded of longtan reservoir, relatively accurate and reasonable flood season staging is obtained:the pre-flood season is from April 12 to May 31, the main flood season is from June 1 to August 31, and the post-flood season is from September 1 to November 9.Based on the scheme of flood season staging, flood stage design flood are ascertained by Installment of the maximum cross-sampling methods and P-Ⅲ type curve line method. Based on the design flood results of flood season staging, Flood regulating calculation is preceded, and the reservoir limited water level which only considering the Longtan reservoir flood control requirements is detennined according to Longtan preliminary design scheduling rules and river basin flood control target. The downstream of river basin flood control demand for Longtan flood control capacity in different flood season stages is considered comprehensively, the final reservoir limited water level of each installment are obtained, flood limit water level of the main flood season which is from June 1 to July 15 is 361.87 meters, flood limit water level of the main flood season which is July 16 to August 31 is 368.40 meters, flood limit water level of post-flood season is 378.45 meters. Finally,risk and benefit of limited water level of reservoir stage is analyzed and evaluated, It is concluded that the adjustment of limited water level does not increase the risk of the reservoir flood control,but can increase the corresponding power generation benefit of ￥228 million and water supply of 1.047 billion m3, proved the feasibility of the limited water level by adjusting scheme.