青藏高原多年冻土活动层厚度对气候变化的响应

Responses of active layer thickness on the Qinghai-Tibet Plateau to climate change

活动层厚度变化将会对多年冻土区生态系统、地气间能水平衡和碳循环等产生重要影响。利用Stefan公式模拟了1981-2010年青藏高原多年冻土区活动层厚度的分布和空间变化特征。结果表明:多年冻土区活动层厚度平均为2.39 m,活动层厚度在羌塘盆地最小,在多年冻土区边缘、祁连山、西昆仑山、念青唐古拉山活动层厚度较大。在气候变化条件下,青藏高原多年冻土区活动层厚度呈整体增大趋势,在1981-2010年,活动层厚度的变化量为-1.54~2.24 m,变化率为-5.90~10.13 cm·a^(-1),平均每年变化1.29 cm。活动层增厚趋势与年平均气温增大的趋势基本一致,这说明气候变化对活动层厚度变化有很大的影响。

The change of active layer thickness has significant influence on the ecosystem, energy balance and carbon cycle between ground and atmosphere, therfore Stefan formula was used to simulate the distribution and spatial variation of active layer thickness on the Qinghai-Tibet Plateau from 1981 to 2010. It is found that the active layer thickness is 2.39 m in average in permafrost regions, which is the smallest in Qiangtang Basin and the largest in the marginal zones of permafrost regions. Active layer thickness is larger in the Qilian Mountains, the West Kunlun Mountains and the Nyainqentanglha Mountains. Owing to climate change, active layer thickness on the plateau has an increasing tendency; during the 30 years from 1981 to 2010, the active layer thickness had changed from -1.54 to 2.24 m, with a change rate of -5.90 to 10.13 cm·a-1 and an average rate of 1.29 cm·a-1. The change of active layer thickness is basically consistent with the change of mean annual air temperature, which indicate that climate change has a great impact on the active layer thickness.