据1991年特大洪涝过程的物理分析试论江淮梅雨预测

An Essay of Meiyu Prediction in the Light of the Syno-Dynamical Study of Summer Monsoon Behavior during 1991 Flood in China

本文以１９９１年江淮梅雨为个例，通过对特大洪涝形成过程的物理分析，就梅雨预测问题提出了一些认识。分析表明，１９９１年江淮流域较长梅雨期内所发生的３场大暴雨是很有代表性的，它们是大气环流季节转变不同进程中的产物，因而具有不同的环流背景和降水性质，且在洪涝的形成中起着不同的作用。据此，我们提出了江淮梅雨的３个模型，指出应在由春夏之交到盛夏这个较长时期内分阶段地考虑梅雨预测。另外还指出，确定雨带的落区，不但应强调副高和东南季风活动对雨带南北进退的作用，而且也要注意西南季风的活动会导致雨带东西向的摆动。最后。

Based on the case study of Meiyu over Changjiang-Huaihe River basin (Jianghuai) in 1991, a better understanding of Meiyu prediction has been obtained Physical analysis of the process of excessively flood reveals that the three episodes of heavy rain of this Meiyu event are of most representative They result from unique atmospheric circulation patterns at different stages of its transition season Thus, with different synoptic backgrounds and precipitation natures, they play quite different roles in the formation of the flood With such understanding, three general conceptual models of Meiyu are put forward, which suggests that Meiyu prediction should be considered in time frame of a long period from spring to summer, and then it may be divided into several subperiods, thus Meiyu prediction being made stage by stage It is also pointed out that in order to determine the location of major seasonal rain belt, we should emphasize not only the activity of subtropical high in west Pacific Ocean and southeast monsoon which generally control the northward and southward movement of rain belt, but also the activity of southwest monsoon which may lead to the zonal movement of rain belt Finally, the significance of such diagnostic study for the physical process of flood and drought in the method of numerical prediction is discussed