降水预报在水库汛限水位动态控制中的可用性研究

利用降水短期预报和实况资料,分析预报某一量级降水条件下实况降水量级的概率分布。从防洪安全角度出发,重点分析某一量级降水预报条件下漏报各量级降水的可能性。并采用适线法,求解与经验点据拟合最优的水文频率曲线统计参数,估算各量级降水预报条件下实况降水的概率分布。分析结果显示,不同量级降水预报的可信度不同,各量级降水预报均表现出漏报率小、空报率大的特征;结合水文频率曲线,讨论了在汛限水位动态控制中如何应用各量级降水预报的问题。

Usability of Precipitation Prediction in Dynamical Controlling of Flood Control Limit for Reservoirs

The probability distribution of observed precipitation grades under a certain precipitation grade is analyzed and predicted on the basis of precipitation predictions and observations in Tianjin.From the viewpoint of flood control,the emphasis is put on the possibility of underestimated precipitation events.Adopting the curve fitting method and determining the empirical statistic parameter from the hydrological frequency distribution curve,the precipitation distributions corresponding to the precipitation prediction of each grade are estimated.Results show that the reliabilities of precipitation predictions are different,and the possibility of underestimated events is bigger than that of overestimated ones for the precipitation predictions of all grades.The procedure to use precipitation predictions for controlling the water level of the reservoir during the flooding season is presented.