流域水电站群风险效益综合规划理论及应用

Risk-Benefit Comprehensive Planning Theory for Hydropower Station Group in a Basin and Its Application

对单个水电站和流域水电站群的风险评价理论进行研究,构建流域水电站群风险效益综合规划理论框架,在简化假设条件下,提出了参数意义明确、物理量易于得到的概化数学模型。大渡河流域已建的梯级水电站风险效益分析可知,发电效益高、风险小的发电为主的水电站不一定优于发电效益相对较低、风险也相对较大但调蓄能力强的综合水利枢纽;在经济发达、人口密集的地区及其上游附近进行水电开发时,应更多考虑调蓄能力建设,或建低水头电站以降低溃坝洪水风险;流域风险关键梯级是拥有大型水库的梯级,流域风险限制梯级是拥有大调节库容的电站,流域风险放大梯级是位于高坝大库下游附近的调蓄能力相对不足、挡水建筑物为超载能力弱的土石坝的电站。

By the research of risk assessment theory from single hydropower station to hydropower station group in a basin,a theoretical framework of risk-benefit comprehensive plan for hydropower station group in a basin is firstly established.Then,under simplifying assumptions,a generalized mathematical model with clear parameter meaning and easily accessible physical quantity is proposed.Based on the risk and benefit analysis of the existing cascade hydropower stations in Dadu River basin,the conclusions are as follows:(a)the hydropower stations with higher power generation benefit and lower risk are not necessarily superior to those with lower power generation benefit and higher risk but large regulated storage capacity;(b)when the hydropower development is implemented in economically developed and densely populated areas or near the upstream areas,more consideration should be given to the construction of regulated storage capacity,or consider low-head power stations to reduce the risk of dam-break flooding;and(c)the critical cascade of basin risk is the cascade with large reservoirs,the limiting cascade of basin risk is the power station with large regulated storage capacity,and the magnifying cascade of basin risk is the power station with relatively insufficient storage capacity and water retaining structure of earth-rockfill dam near the downstream of high dam and large reservoir.