The Presence of Hydraulic Barriers in Layered Snowpacks: TOUGH2 Simulations and Estimated Diversion Lengths
The Presence of Hydraulic Barriers in Layered Snowpacks: TOUGH2 Simulations and Estimated Diversion Lengths
复制标题
分层积雪中水力屏障的存在：TOUGH2 模拟和估计导流长度
作者：
R. Webb;S. Fassnacht;M. Gooseff;S. Webb
雪在景观中的分布是许多山区流域水文循环的重要组成部分。以雪为主的溪流将根据积雪融化的时间和融化的水到达溪流的滞后时间而在高峰流量上有所不同。当积雪在冬季积聚时，具有不同水力特性的可变层可以形成水力屏障。本研究使用位于科罗拉多州斯普林克里克密集研究区(NASA CLPX数据集的一部分)的三个雪坑的数据来模拟水力屏障。选择了北、南和相对平坦的坡度数据来表示在不同条件下发生的可变变质作用。使用TOUGH2的EOS9模块在0.1、1.0和5.0 mm/h的稳态入渗率下进行了模拟。利用现有的毛细管屏障土壤物理近似计算了额外的分流长度估计。结果表明，分层积雪内存在产生多个渗透性和毛细屏障的条件，尽管毛细屏障仅在北面积雪的模拟中被识别。毛细屏障的导流长度从1.0米到大于25米，渗透性屏障的长度从2.5到9.5米。此外，在界面上方的层中，颗粒尺寸为0.6毫米或更小才能产生毛细屏障。这些结果表明，在融雪过程中，水在渗入地表之前有很高的向下重新分配的潜力。更好地理解积雪作为多孔介质将改进未来的水文模拟。
The distribution of snow across a landscape is an important component in the hydrologic cycle of many mountainous watersheds. Snow-dominated streams will vary in timing and volume of peak flow depending on when the snow melts and the lag time for the meltwater to reach the stream. As a snowpack accumulates during winter months, variable layers with different hydraulic properties can form hydraulic barriers. Hydraulic barriers were simulated in this study using data from three snow pits located in the Spring Creek Intensive Study Area (part of the NASA CLPX dataset) of Colorado. Data for north, south, and relatively flat aspect slopes were chosen to represent the variable metamorphism that occurs under different conditions. Simulations were conducted at steady-state infiltration rates of 0.1, 1.0, and 5.0 mm/h using the EOS9 module of TOUGH2. Additional diversion length estimates were calculated using existing soil physics approximations for capillary barriers. Results demonstrate that conditions are present within a layered snowpack to produce multiple permeability and capillary barriers, though capillary barriers were only identified in simulations on the north aspect snowpack. Diversion lengths of capillary barriers ranged from 1.0 m to greater than 25 m, and permeability barriers ranged from 2.5 to 9.5 m. Furthermore, a grain size of 0.6 mm or less in the layer above an interface is necessary to produce a capillary barrier. These results suggest that during snowmelt water has high potential to be redistributed downslope prior to infiltrating the ground surface. A better understanding of a snowpack as porous media will improve future hydrologic modeling.
融水流动路径的空间和时间变化：来自 100 多个雪蒸渗仪网格的见解
影响因子：
5.4
作者：
Webb, R. W.;Williams, M. W.;Erickson, T. A.
通讯作者：
Erickson, T. A.