塔里木盆地风蚀气候侵蚀力的计算与分析

利用塔里木盆地周边及腹地13个气象站1961～2007年的观测资料,选择联合国粮农组织给出的风蚀气候因子指数计算公式,计算了塔里木盆地风蚀气候因子指数值,以此阐述了风蚀气候侵蚀力的基本特征。结果表明,多年平均风蚀气候因子指数C值的分布范围为6.3～39.6,整个盆地的平均值为17.5;从空间分布来看,C值由盆地西部向东部呈增大趋势,最大值出现在盆地东南缘的若羌;风蚀气候因子指数具有显著的季节变化,春季最大,夏季次之,秋季再次之,冬季最小;近50 a来,风蚀气候因子指数总体上呈减小趋势,说明风蚀气候侵蚀力在降低;风蚀气候侵蚀力主要受风速的作用,与降水的关系不显著。

Calculation and Analysis on Wind Erosion Climatic Erosivity in the Tarim Basin

The wind erosion climatic factor index in the Tarim Basin of northwester China was calculated with the function given by the UN Food and Agriculture Organization and based on the meteorological data from 13 weather stations during 1961-2007.The basic features of the wind erosion climatic erosivity(C) in the Tarim Basin were then set forth.The average annual wind erosion climatic factor indexes were in range of 6.3~39.6 in the 13 weather stations,and the average value was 17.5.The C value appeared an increase trend from the west to the east of the basin,with the largest in Ruoqiang in the southeastern margin of the basin.As for seasonal variation,the C value appeared the largest in spring,followed by summer,autumn and winter in order.In the recent 50 years,the wind erosion climatic factor index exhibited a decreasing trend in the Tarim Basin,which showed that the wind erosion climatic erosivity decreased in this region.The wind erosion climatic erosivity is mainly restricted by wind speed in the Tarim Basin,and it has no significant relationship with precipitation.