东北低山丘陵区季节性积雪特性研究

为探究东北低山丘陵区冬季积雪物理特性变化过程,利用超声雪深监测仪和Snow Fork雪特性分析仪采集积雪物理特性(积雪深度、积雪密度、液态含水率)数据,分析积雪深度、密度和液态含水率随时间的变化特征及其在垂直剖面上的变化过程。结果表明:主要积雪期为11月下旬至翌年2月中下旬,积雪深度与雪层温度、气温呈显著负相关关系,与降雪量呈正相关关系。积雪消融主要集中在10:00—18:00之间,且积雪消融相对于气温表现出滞后性,滞后时间约为4h。积雪初(12月1日观测),雪底层密度为0.198g/cm~3,表层为0.126g/cm~3,从底层至表层呈逐渐减小趋势。随着雪底层形成深霜,中间层5—10cm的积雪密度大于表层和底层。积雪0—5,5—10,10—15cm层平均液态含水率分别为0.308%,0.319%和0.205%,中间层最高,整体表现为单峰型。积雪液态含水率与积雪密度呈显著正相关关系(r=0.866,p0.05)。研究结果将为融雪径流形成、融雪侵蚀防治以及季节性积雪区生态系统功能评估提供基础数据。

Research on the Characteristic of Seasonal Snow at Low Hill Area in Northeast

In this study, we aimed to investigate the characteristic of seasonal snow at low hill area in Northeast. The time serials of snow parameters (snow depth, snow density and liquid water content) were discussed, based on the date collected by Snow Fork and ultrasonic snow deep sensor. The results showed that: The main period of snow cover was from November to February, and the correlative analysis showed that snow depth had a negative correlation with snow temperature and air temperature, while there was a positive correlation between it and snowfall. Most part of snow was melting at the period of 10:00 to 18:00. The snow depth had distinct positive relation to the snow temperature four hours ahead. At the beginning of snow covering (December 1st), the snow density of the bottom layer and the surface layer was 0.198 g/cm3 and 0.126 g/cm3 respectively. It decreased gradually from the bottom layer to the surface one, and the snow cover density of middle 5-10 cm layer was greater than the surface and bottom ones when the depth hoar was appeared within bottom snow layer. The average of snow liquid water content within 0-5 cm, 5-10 cm and 10-15 cm layer was 0.308%, 0.319% and 0.205% respectively. The liquid water content of snow cover, which showed a single-peak type with the variation of depth in each snow cover layer, within middle 5-10 cm layer was greater than that at the surface and bottom ones. There was a positive correlation between the liquid water content of snow cover and its density (r=0.866, p<0.05). This study could provide fundamental data for the?generation?of?snowmelt?runoff, snowmelt erosion prevention and the assessment?of ecosystem fuction in the area of seasonal snow cover.