短期降雨预报失误对安康水库防洪预报调度的影响

Impact of Short-term Rainfall Forecast Error on the Flood Dispatching for Ankang Reservoir

针对应用短期降雨预报信息实施水库防洪调度问题,研究降雨预报失误对水库调度的影响。以安康水库为例,分析了未来24 h短期降雨预报精度及分布规律,利用贝叶斯定理,计算考虑降雨预报信息的防洪调度风险发生事件寄予各个量级降雨预报失误造成的概率。结果显示:在当前的降雨预报水平下,安康水库利用不同量级降雨预报信息实施防洪调度时,Ⅰ量级(预报无雨)降雨预报失误对水库调度影响不大,可用于指导水库优化调度;Ⅱ量级("预报小雨")降雨预报失误对小洪水调度影响较大;Ⅲ量级(预报中雨及以上)降雨预报失误对大洪水调度影响较大,可作为汛期水库优化调度的参考指标。

In order to study the influence of rainfall forecast error on flood control operation,the short-term rainfall forecast accuracy and distribution for the next 24 hours in Ankang reservoir were analyzed.The probability of flood control operation risk event owing to short-term rainfall forecast error was calculated based on Bayes theorem.Results show that,as for flood operation based on rainfall forecast information of different levels under the current rainfall forecast level,the forecast error at level I（forecasting＂no rain＂） has little effect on flood operation,hence can be used to guide optimal operation for reservoir;the error at level II（forecasting ＂light rain＂） has great impact on small flood operation and the error at level III（forecasting＂no less than moderate rain＂） has great impact on large flood control operation,thus can be taken as reference index in the flood optimal operation.