青藏高原冻融侵蚀敏感性评价与分析

冻融侵蚀是我国仅次于水蚀和风蚀的土壤侵蚀类型。青藏高原由于其海拔高、辐射强、气温低的特点，是我国冻融侵蚀较严重的区域。选择影响冻融侵蚀的5个主要因子：气温年较差、降水量、坡度、坡向、植被覆盖度进行定量研究，分析青藏高原冻融侵蚀敏感性强度及空间分布特征。结果表明：（1）青藏高原冻融侵蚀区面积为149.02×10⁴ km²，占青藏高原总面积的62.20%；冻融侵蚀敏感区的面积为56.80×10⁴ km²，中度及以上敏感区面积为27.39×10⁴ km²，占冻融侵蚀敏感区面积的48.22%；（2）冻融侵蚀敏感性空间分布差异明显，中度以上敏感区主要分布在青藏高原南部和东南部、喀喇昆仑山、祁连山、横断山区等地区。

Assessment and analysis of the freeze-thaw erosion sensitivity on the Tibetan Plateau

Following the water erosion and wind erosion,freeze-thaw erosion is the third strong soil erosion in China.The Tibetan Plateau is a severe freeze-thaw erosion area owing to its high altitude,strong radiation and low temperature.Five indices are chosen to assess freeze-thaw erosion.They are annual range of temperature,annual precipitation,slope,slope aspect and vegetation coverage.The results show:(1) The distribution of freeze-thaw erosion is very extensive in the Tibetan Plateau,with the freeze-thaw erosion area of 149.02 × 104 km2,accounting for 62.20％ of the total area of the Tibetan Plateau.Freeze-thaw erosion sensitive area is 56.80 × 104 km2,among which moderate and more sensitive area is 27.39 × 104 km2,accounting for 48.22％ of the total freeze-thaw erosion sensitive area in the Tibetan Plateau;(2) The regional differentiation of freeze-thaw erosion sensitivity is obvious.Different intensities of freeze-thaw erosion sensitivity appear in different regions.The sensitivity is heavy in south and southeast of the plateau,Karakoram Mountains,Qilian Mountains,and Hengduan Mountains.