天山北坡季节性积雪消融对浅层土壤水热变化影响研究

Influence of seasonal accumulated snow melting on the moisture and heat of shallow soil layer in northern slope of Tianshan Mountain

融雪期,浅层土壤水热变化影响融雪水下渗及积雪产流过程,是融雪产流模拟及汇流计算的重要参数。本研究以天山北坡军塘湖流域为研究区,从积雪消融角度来分析浅层土壤水热变化情况,通过分析积雪消融期土壤剖面水分、温度的变化规律确定二者之间的定量关系。结果表明,气温对土壤温度的影响随着土壤深度增加减弱,积雪越厚,土壤温度越高;土壤水分受地温影响较大,雪水入渗能在一定程度上补给土壤水,但消融后期剧烈的蒸发引起土壤表层10cm内水分损失较多。阴阳坡土壤水分均随时间呈中等变异(除阳坡60cm),在30-60cm土壤层土壤水热间表现出显著的相关性。此结果为该区域农业生产、春季融雪洪水预警进一步研究提供参考。

In snow-melting period,the hydrothermal change of shallow soil layer has impact on snowmelt water infiltration and accumulated snow runoff generation,so it is an important parameter of snow melting runoff generation simulation and flow concentration calculation. In this research,the Juntang Lake basin at the northern slope of Tianshan Mountain was taken as the study area,the hydrothermal change of shallow soil layer was analyzed from the perspective of accumulated snow melting,and the quantitative relation between the soil profile moisture and temperature during snow-melting period was determined by analyzing the change rule of these two. The results indicate that the influence of air temperature on soil temperature reduces as soil depth increases,as the thicker the accumulated snow is,the higher the soil temperature becomes; earth temperature has a larger impact on the soil moisture,and snow water infiltration can supply soil water to some extent,while the acute evaporation during the later snow melting period causes more moisture loss to surface soil within 10 cm. Soil moisture of both sunny slope and shady slope shows a medium variation（ except the soil within surface 60 cm of the sunny slope）over time and the soil moisture and heat in soil layer of 30-60 cm show a significant correlation. This result provides reference for further studies on agricultural production,spring snowmelt flood warning for this region.