新疆天山西部巩乃斯河谷积雪与森林/草地 覆盖条件下季节冻土特征分析

不同的覆盖条件下，季节冻土的特征会存在差异。为了分析积雪与森林/草地覆盖条件下季节冻土的特征，在新疆天山西部巩乃斯河上游的中国科学院天山积雪雪崩研究站的实验场地监测了森林-积雪，草地-积雪，以及草地覆盖条件下季节冻土的冻结深度，并对有无积雪覆盖条件下季节冻土发育过程中的土壤温度和土壤含水量进行了跟踪测量。结果表明：森林-积雪覆盖条件下季节冻土的冻结深度最浅，草地-积雪覆盖条件下次之，草地覆盖条件下最深。积雪的存在可以改变季节冻土的冻结深度，还会影响土壤温度和土壤含水量变化。在季节冻土的发育阶段，积雪的隔热作用使得有积雪覆盖条件下土壤温度和土壤含水量较高；在积雪消融阶段，由于积雪融水的补给，土壤含水量也相应地增加，积雪消失后由于蒸发的存在导致土壤含水量减少。

Analyses on the characteristics of seasonally frozen ground under snow cover and forest/grassland in Kunes Valley,western Tianshan,Xinjiang

The characteristics of seasonally frozen ground are different under snow cover, forest and grassland. In order to analyze the differences of seasonally frozen ground under snow cover, forest and grassland, in this study, the seasonally frozen ground depth under forest and snow cover, grass and snow cover, and grassland were observed in Tianshan Station for Snow Cover and Avalanche Research, Chinese Academy of Sciences, in the upstream of Kunes River, western Tianshan, Xinjiang. The variations of soil temperature and soil moisture were observed under grassland & snow cover and grassland conditions. The results indicated that the frozen depth under grassland was the deepest while that under forest and snow cover condition was the shallowest. Snow cover influences not only the frozen depth, but also the soil temperature and soil moisture. In the seasonally frozen ground development period, the soil temperature and soil moisture increased due to the insulation effect of snow cover. During the thawing period, the soil moisture increased due to supply of snow melt water firstly and then decreased due to evaporation.