1960-2017年阿拉善高原风蚀气候侵蚀力时空演变

根据阿拉善高原8个气象站观测资料，利用联合国粮农组织公式计算风蚀气候因子指数值（C值），分析气候侵蚀力时空演变特征。结果表明：① 阿拉善高原C值为15.0~160.0，平均为67.7。② 从空间分布来看，C值由拐子湖分别向东南、西南减小；拐子湖站高达156.1，而阿拉善高原东南部的腾格里沙漠南缘C值为20~30；西南部合黎山一带C值下降至30~35。③ 季节变化明显，春季最大，夏季次之，秋季最小；春季和夏季的C值之和约占全年的62.6%。Mann-Kendall（M-K）检验分析表明，风蚀气候侵蚀力在1990年发生突变。拐子湖站年C值增加趋势显著，其余各站年C值均显著下降。风速是阿拉善高原风蚀气候侵蚀力的决定性气象因子。

Spatio-temporal Evolution of Wind Erosion Climatic Erosivity in the Alxa Plateau During 1960-2017

Based on the meteorological data from 8 weather stations in the Alxa Plateau, the wind erosion climatic factor index (C factor) was calculated using the function given by the UN Food and Agriculture Organization, and the spatio-temporal variation of wind erosion climatic erosivity was analyzed. The results showed that the C factor of Alxa Plateau ranged from 15.0 to 160.0 and the average was 67.7. On the spatial, C factor decreased from Guaizi Lake to Southeast and southwest respectively; the C-factor, at Guaizi Lake station was 156, while the C factor, on the southern edge of Tengger Desert in the southeast of Alxa Plateau was 20-30 and that of Heli Mountain in the southwest was 30-35. The seasonal variation of C factor was distinct. On the whole, the largest value was in spring, the second in summer and the smallest in autumn. The sum of C factor in spring and summer accounted for 62.6% of the whole year. Mann Kendall (M-K) test showed that the wind erosion climatic erosivity had abrupt change in 1990. The annual C factor of Guaizi Lake station increased markedly, while other stations decreased significantly. Wind speed was the decisive factor of wind erosion climate erosivity in the Alxa Plateau.