Abstract: Climate change plays an important role in dynamic changes of snow cover and soil moisture content. A warming weather in last decades had resulted in the shortening of snow cover season, reduction of water storage in snowpack and earlier snowmelt in spring, and these affected the spatiotemporal distribution of soil moisture content. In this study, a temperature increase experiment was performed at the Tianshan Station for Snow Cover and Avalanche Research during snowmelt season with a temperature increase system based on the principle of TFACE. The field experiment was conducted under three treatments: natural status, temperature increase treatment Ⅰ (air temperature was increased by about 2 ℃) and temperature increase treatment Ⅱ (air temperature was increased by about 4 ℃). The results indicated that snowmelt rate was significantly increased under both cases of temperature increase and more dust adhering to snow surface due to strong air convection caused by local warmer air. Snow cover disappeared 19 and 25 days earlier under the treatment Ⅰ and treatment Ⅱ than that under nature conditions, respectively. Corresponding to the change of snow cover status, soil moisture content was increased in varying degrees at different soil depth. Maximum soil moisture content occurred 13 and 22 days earlier, which revealed that stream flow peak might come earlier under climate change in the future in the watersheds where snowmelt water is an important water source. The field experiment provided an evidence to prove that global warming will bring a farreaching effect on the spatiotemporal distribution of regional water resources.  

Key words: climate change, snow cover, soil moisture content, temperature, snowmelt rate, Ili