THE BASIC CHARACTERISTICS OF HEAVY SNOWSTORM PROCESS AND SNOW DISASTER DISTRIBUTION IN EASTERN PASTORAL AREAS OF QINGHAI-XIZANG PLATEAU

The 26 weather stations in eastern pastoral areas of Qinghai Xizang Plateau have appeared 1 689 heavy snowstorm weather processes in the past 30 years. In terms of our standard, snow disaster occurred 410 times totally. By means of statistic analysis, we concluded some preliminary time space distribution characteristics of heavy snowstorm processes and snow disaster. The results show that Jiuzhi was the frequent center of heavy snowstorm processes and snow disaster, while Qingshuihe was the high value center of snow disaster and disaster forming. The probability of disaster forming reached to 80.3% in the later winter, but only 14.3% in the spring. As a result, tomake an impact on snow disaster is getting more and more serious because of the significant increment of heavy snowstorm processes and precipitation, particularly, it becomes more frequent since 1990's.