致洪暴雨预报模型应用研究

Prediction Models of Flooding Rainstorm and Their Application

通过普查、分析黄河花园口站洪峰流量大于等于4000m3/s的黄河中游8次洪水过程,着重分析了洪水过程中小花间区域致洪暴雨发生前的天气学特征,归纳出造成小花间洪水过程的天气形势主要有鞍型场和台风倒槽两大类型,并建立了相应的500、700hPa高度场模型和热力、水汽条件诊断模型及动力条件物理量诊断模型,并采用相似离度进行入型判别。该预报模型在2003年预报业务试验中,对黄河秋汛期间发生在小花间区域的致洪暴雨过程进行了较为成功的预报。

An analysis was made of the weather patterns before the flooding rainstorms corresponding to the flooding processes in the middle reaches of the Yellow River above the forecast standard （peak discharge ≥4000 m^3/s at Huayuankou Station）. It was concluded that there were two types of weather patterns caused floods over the Xiaolangdi-Huayuankou region： saddle field and inverted typhoon trough. The corresponding height field forecast models for 500 and 700 hPa and the diagnosing models for thermal, moisture and dynamic conditions were developed, and the pattern identification was conducted by means of analog deviation. The models were put to trial operational use in the autumn flooding season of the Yellow River in 2003. The flooding rainstorm process occurred in the Xiaolangdi-Huayuankou region was predicted successfully.