青藏高原东南缘复杂地形条件下降水特征分析

针对青藏高原东南缘泥石流灾害活动频繁,但形成区缺乏较为准确的降水资料的现实需求,按照水系的分水岭将研究区分为6个区域,并利用区内60个气象观测站点1981~2010年年均降水量、海拔高度、坡向、坡度资料,结合GIS和统计分析,建立了各分区的降水垂直分布关系式,并以金沙江流域的拉哇沟、大渡河流域的江咀沟对该统计模型进行了初步验证。结果显示:针对不同的流域,该降水垂直分布关系式能够获取缺气象观测站点的山区降水数据,大体上适用于青藏高原东南缘降水测算,能为泥石流等山地灾害形成区的汇流计算提供参考。

Precipitation characteristics in complex terrains in southeast margin of Qinghai-Tibet Plateau

Mountain hazards such as debris flows are frequent in the southeastern margin of Qinghai-Tibet Plateau, but the area is lack of accurate precipitation data.In order to evaluate the rainfall in the data-lack area, we divide the study area into 6 regions according to its hydrographic watershed and provide a precipitation vertical distribution formula based on statistic data including average annual precipitation, altitude, slope aspect, gradient, etc.from 60 meteorological stations in the 6 regions between 1981 and 2010.It is founded that the annual rainfall is well related to the altitude, slope aspect and gradient.The formula is then verified with the data in Lawagou Watershed in the Jinsha River Bain and Jiangzuigou Watershed in the Dadu River Basin.The results show that the formula can obtain a clear vertical distribution of rainfall for the area lack of meteorological stations and is generally applicable to calculating precipitation in the southeastern margin of Qinghai-Tibet Plateau, which can provide references for the warning and prevention of the mountainous hazards.