1998-07-06云南境内金沙江流域暴雨泥石流的气象成因

The Meteorological Causes for Rainfall Debris Flow in Jinsha River Basin of Yunnan Province on July 6,1998

1998-07-06昭通地区发生了不同程度泥石流灾害,以此为例,应用气象资料及其带通滤波方法,分析了引发此次暴雨泥石流的天气成因。结果表明:此次暴雨泥石流发生的引发因素除了地面因素和前期降水使地面达到饱和外,中尺度辐合天气系统———西南涡以及充分的水汽输送是直接造成此次暴雨泥石流灾害的天气系统。

Debris flow calamity broke out in Zhaotong area on July 6,1998, take it as example. Applied meteorological data and scale separated method, the synoptic causes for the rainfall debris flow is studied. The result indicated that climatic features, mesoscalesynoptic system-southwest China vortex and water vapor transportation is the mainmeteorological causes besides the geological and the former rainfall causes. The rainfall days are much more on July, andconnectivity rainfall more than 15 days. The west pacific subtropichigh was strong at 00BST July 6, there was the upper trough in the between Yunnan and Sichuan, the debris flow before this upper trough. At this day when the debris flow broke out, weapplied the meteorological and scale separated a low disturbances system, and in this system neighbor was high disturbances area. Which lead to cold and warm air convergence to low area, and finally The Zhaotong area had heavy rainfall.