Research On Reservoir Staging Operation In Flood Season And Effect Evaluation

Exploiting the seasonal variation of flood as the breakthrough point and aiming at flood resource utilization, this thesis conducted studies in the aspects of division of flood season, ratiocination of stage design flood, determination of limited water level, and effect evaluation of reservoir flood season division. Significant research outcome has been achieved through a practical engineering analysis of Chengbihe reservoir.This thesis gives a comprehensive analysis of the case of Chengbihe reservoir from1963to2011, considering factors including the inflow, surplus water, fill storage ratio, engineering condition of the reservoir dam, need of water supply of the neighboring area and the need of local social development, so as to demonstrate the necessity and feasibility of reservoir flood season staging scheduling. The time spans of flood season and non-flood season were determined by analyzing the average daily rainfall on the reservoir. The flood season lasted202days from Apr.13th to Oct.31st, while the non-flood lasted from Nov.1st to Apr.12th of the next year, with a total duration of163days.The thesis use fractal theory to calculate and analyze the data of the average daily rainfall series, the maximum annual rainfall series, the average daily runoff series and the maximum daily runoff series collected over decades. As a result, the time spans of the pre-flood season, the major flood season and the latter flood season were finally determined as from Apr.13th to Jun.6th, from Jun.7th to Sept.9th, and from Sept.10th to Oct.31st, respectively.After the application of correlation analysis and theoretical frequency curve analysis for the purpose of calculating the staging design flood, cubic spline interpolation function was implemented in the simulation of flood routing. Ultimately, at the premise that the principle of no lowering of the flood control standard must be obeyed and the reality and relevant regulations must be considered, the flood control level of the reservoir in each season the flood control level of the reservoir in each season were established as:185m for the pre-flood season and major flood season and185m～187.5m for the latter flood season.Based on benefit and risk analysis theory, this thesis carried on an effect evaluation about reservoir flood season staging scheduling. The results showed that the measure could bring an annual average benefit ranging from88to162million RMB. While the corresponding average annual expected risk was226350RMB. The benefit was much higher than the risk, which proved that properly raising the flood control level of latter flood season is reasonable and feasible.