近50年青海省风蚀气候侵蚀力时空演变趋势

Tendency of Spatiotemporal Evolution of Wind Erosion Climatic Erosivity in Qinghai Province in Recent 50 Years

利用青海省43个气象站1961-2010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,计算了青海省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值得分布范围为-12.9～160.1,整个青海省的平均值为32.4;从空间分布来看,C值由西北部向东南部呈减小趋势,最大值出现在柴达木盆地的茫崖;风蚀气候因子指数具有显著的月际和季节变化,春季最大,冬季次之,夏季最小;近50 a来风蚀气候因子指数总体上呈现减小趋势,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制约,与降水和沙尘暴日数的关系不显著.

By making use of calculation method of wind erosion climatic erosivity factor index developed by FAO and observation data from 43 meteorological stations during 1961 to 2010 in Qinghai Province, we analyzed the basic features of wind erosion climatic erosivity. The results showed that the range of wind erosion climatic erosivity factor index of C value varied from -- 12.9 to 160.1 ; the average of C value was 32.4 in Qinghai Province. Spatially, C value displayed the decrease trend from northwest to southeast and the maximum of C value appeared at Mangai in the Qaidam Basin. Wind erosion climatic erosivity factor had seasonal and inter-monthly variation, the highest value showed in spring, the second one in winter and the lowest one in summer. Wind erosion climatic erosivity factor had the decrease tendency in recent 50 years which revealed that wind erosion climatic erosivity was reducing. Wind speed was main restricting factors of wind erosion climatic erosivity. The relationship between wind erosion climatic erosivity, precipitation and sandstorm days was not significant.