红水河龙滩水电站区间河系洪水预报方案研究

Study on River System Flood Forecasting Scheme for Longtan Hydropower Station Interval in Hongshui River

龙滩水电站是珠江流域防洪控制性工程,但目前缺乏较完整的河系洪水预报方案。为充分发挥龙滩水电站的防洪调蓄作用,选取了雷公滩、沫阳、平里河、平湖和仙人桥等支流控制站点,通过重要子区间分析确定重点关注区域,利用新安江三水源产流模型、三水源滞后演算汇流模型和马斯京根汇流演算法构建龙滩水电站区间河系洪水预报方案。研究结果表明:龙滩水电站最大入库洪水洪量占比通常为无控区间,其次为贵州区支流(蒙江、坝王河、曹渡河、六硐河),两者是洪水预报的关注重点;本研究构建的河系洪水预报方案整体洪峰流量、场次洪量的平均相对误差均为10%,平均确定性系数均在0.75以上,总体结果较好。因此,构建的龙滩水电站区间河系洪水预报方案能够应用于实时洪水作业预报中,也为进一步提升“四预”能力筑牢基础。

Longtan Hydropower Station is a flood control project in the Pearl River Basin,but there is currently a lack of a comprehensive river system flood forecasting scheme.In order to give full play to the flood control and storage function of Longtan Hydropower Station,tributary control stations such as Leigongtan,Moyang,Pinglihe,Pinghu,and Xianrenqiao are selected,and the key areas of concern are determined through the analysis of important sub-intervals.The river system flood forecasting scheme for the Longtan Hydropower Station interval is constructed by using the Xin an River three-source runoff generation model,three-source lag routing convergence model,and Maskingen convergence algorithm.The research results show that the proportion of the maximum inflow flood volume of Longtan Hydropower Station is usually in uncontrolled intervals,followed by the tributaries in Guizhou Province(Mengjiang River,Bawang River,Caodu River,and Liudong River),which are the focus of flood forecasting.The total average relative peak flow error and the average relative flood volume error in the river system flood forecasting scheme are both 10%,and the average deterministic coefficients are above 0.75.The overall results are relatively accurate.Therefore,the river system flood forecasting scheme for the Longtan Hydropower Station interval can be applied to real-time flood operation forecasting,and it lays a solid foundation for further improving the“forecast,early warning,rehearsal,and contingency plan”capability.