青藏高原冻融侵蚀敏感性评价与分析

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

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× 10~4km^2,占青藏高原总面积的62.20%;冻融侵蚀敏感区的面积为56.80× 10~4km^2,中度及以上敏感区面积为27.39× 10~4km^2,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。

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.