1961～2015年雅鲁藏布江流域风蚀气候侵蚀力变化

Variations of Wind Erosion Climatic Erosivity in the Yarlung Zangbo River Basin During 1961-2015

根据雅鲁藏布江流域13个气象站观测资料,利用联合国粮农组织给出的公式计算雅鲁藏布江流域风蚀气候因子指数值,分析雅江风蚀气候侵蚀力基本特征。结果表明,雅江流域风蚀气候因子指数分布范围为4.2～31.9,平均值为14.7。从空间分布来看,风蚀气候因子指数由西向东呈减小趋势,西部可达40,东部加查-米林段降到了5左右。风蚀气候因子指数具有显著的季节变化,春季最大为8.5,冬季次之为5.2,夏季、秋季都很小。雅江流域风蚀气候因子指数年、春季、秋季、冬季下降趋势显著,夏季上升趋势不显著。通过Mann-Kendall(M-K)检验分析可知,风蚀气候因子指数在1987年发生突变。

Based meteorological data from 13 weather stations in the Yarlung Zangbo River Basin, the wind erosion climatic factor index was calculated using function given by the UN Food and Agriculture Organization and the basic features of wind erosion climatic erosivity were analyzed. The results showed that Yarlung Zangbo River wind erosion climatic factor indexes were in range of 4.2-31.9 and the average value was 14.7. On the spatial, wind erosion climatic factor indexes decreases from the west to the east. Wind erosion climatic factor indexes can reach to 40 in the west and reduced to about 5 in the eastern part of Gyaca-Mainling section. The wind erosion climate factor index has a significant seasonal variation. The largest value is in spring with the value of 8.5 and the second large value in winter with the value of 5.2. Summer and autumn show very small value. The trend of wind erosion climate factor index decreased significantly in Yarlung Zangbo River Basin on annual, spring, autumn and winter, while that of summer uptrend is not significantly. Analysis using MannKendall test method shows that the wind erosion climatic factor index has abrupt change in 1987.