不同遮蔽条件下季节性积融雪过程差异规律对比研究

寒旱区季节性积雪融雪水文过程对气候与环境变化高度敏感,研究影响季节性积雪积累与融雪过程的关键因素并进行适应性调控,对维护变化环境下流域水安全与水资源可持续利用具有重要意义。通过对新疆天山北坡乌鲁木齐河流域试验区2017年12月-2018年3月不同遮蔽条件下(林冠下、开阔地)季节性积雪层分层物理特性进行试验观测,分别分析积雪期、融雪期雪层分层物理特性及差异特征。结果表明:积融雪期内,林冠下积雪平均深度略小于开阔地,分层积雪中深霜层与粗粒雪层深度比重较大;积雪期内,开阔地分层积雪液态含水率呈单峰型变化,林冠下分层积雪液态含水率自上而下呈均匀递增趋势,融雪期不同遮蔽条件下雪层液态含水率均随雪深垂直廓线变化呈单峰型,峰值集中在细粒雪层;积融雪期分层积雪密度垂直廓线变化特征基本一致,均呈单峰型。

Comparative study on the difference law of seasonal snowmelt process under different shading conditions

Seasonal snow melting hydrological process in cold and arid regions is highly sensitive to climate and environmental changes. It is of great significance to study the key factors affecting seasonal snow accumulation and snow melting process and to adjust and control them adaptively for maintaining water security and sustainable utilization of water resources in the basin under changing environment. The physical characteristics of seasonal snow layers under different shelter conditions (under canopy and open land) in the Urumqi River Basin experimental area on the northern slope of Tianshan Mountains, Xinjiang from December 2017 to March 2018, were observed and tested. The physical characteristics and differences of snow layers during snow accumulation and melting periods were analyzed respectively. The results showed that during snow accumulation and melting period, the average depth of snow under canopy was less than that of open land, and the proportion of deep frost layer and coarse snow layers were larger than that of the other layers in stratified snow. During snow accumulation period, the liquid water content of snow cover in open land layer changed in a single peak pattern, and the liquid water content of snow cover under canopy layer increased uniformly from top to bottom. The liquid water content of snow layers changed in a single peak pattern with the vertical profile of snow depth in different shelter conditions in snowmelt period, and the peak value concentrated in fine snow layer. The variation characteristics of vertical profile of stratified snow density during snow accumulation and melting period were basically the same, showing a single peak pattern.