Hydrologic connectivity at the hillslope scale through intra‐snowpack flow paths during snowmelt
Hydrologic connectivity at the hillslope scale through intra‐snowpack flow paths during snowmelt
复制标题
融雪期间通过积雪内部流动路径实现山坡尺度的水文连通性
作者：
R. Webb;O. Wigmore;K. Jennings;M. Fend;N. Molotch
季节性融雪期是许多山区水文循环的关键组成部分。由于物理水文流动路径（如纵向积雪内流动路径）导致的融雪时间和速率的变化可能对融水在径流、地下水补给和土壤水分储存之间的分配产生强烈影响。然而，积雪内的流动路径在空间和时间上都是高度可变的，因此很难观察。这项研究利用新的方法来非破坏性地观察雪中液态水含量的时空变化，并结合小区实验来解决研究问题：积雪内流动路径对融化过程中液态水在海拔梯度上的下坡运动的影响程度是什么？这项研究在北方科罗拉多进行，研究地块从雨雪过渡区到高山。结果表明，随着海拔的升高，积雪内流动路径的影响范围越来越大，显示出较高的山坡连通性，产生较大的积雪内融水积累贡献区域，量化为从融化速率估计产生液态水含量变化所需的上坡贡献区域。对于树线上方、树线附近和树线下方地块，累积液态水的总有效积雪内贡献面积分别为17、6和0 m2。染料示踪实验表明，毛细管和渗透性障碍导致在更高的海拔积雪内流动路径的数量和厚度增加。此外，我们还利用航空摄影测量结合探地雷达调查的作用，这个水文过程中的小流域尺度。这里的结果表明，内积雪流动路径的影响超出了地块规模，影响小流域尺度的积雪内液态水的储存和传输。
The seasonal snowmelt period is a critical component of the hydrologic cycle for many mountainous areas. Changes in the timing and rate of snowmelt as a result of physical hydrologic flow paths, such as longitudinal intra‐snowpack flow paths, can have strong implications on the partitioning of meltwater amongst streamflow, groundwater recharge, and soil moisture storage. However, intra‐snowpack flow paths are highly spatially and temporally variable and thus difficult to observe. This study utilizes new methods to non‐destructively observe spatio‐temporal changes in the liquid water content of snow in combination with plot experiments to address the research question: What is the scale of influence that intra‐snowpack flow paths have on the downslope movement of liquid water during snowmelt across an elevational gradient? This research took place in northern Colorado with study plots spanning from the rain‐snow transition zone up to the high alpine. Results indicate an increasing scale of influence from intra‐snowpack flow paths with elevation, showing higher hillslope connectivity producing larger intra‐snowpack contributing areas for meltwater accumulation, quantified as the upslope contributing area required to produce observed changes in liquid water content from melt rate estimates. The total effective intra‐snowpack contributing area of accumulating liquid water was found to be 17, 6, and 0 m2 for the above tree line, near tree line, and below tree line plots, respectively. Dye tracer experiments show capillary and permeability barriers result in increased number and thickness of intra‐snowpack flow paths at higher elevations. We additionally utilized aerial photogrammetry in combination with ground penetrating radar surveys to investigate the role of this hydrologic process at the small watershed scale. Results here indicate that intra‐snowpack flow paths have influence beyond the plot scale, impacting the storage and transmission of liquid water within the snowpack at the small watershed scale.
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DOI：
10.1002/2015jf003593
发表时间：
2015
期刊：
Journal of Geophysical Research: Earth Surface
影响因子：
--
作者：
Heilig;C. Mitterer;L. Schmid;N. Wever;J. Schweizer;H.-P. Marshall;O. Eisen
通讯作者：
O. Eisen
结合地面穿透雷达与地面激光雷达扫描来估计季节性积雪中液态水含量的空间分布
影响因子：
5.4
作者：
Webb, R. W.;Jennings, K. S.;Fend, M.;Molotch, N. P.
通讯作者：
Molotch, N. P.
影响因子：
5.2
作者：
Schmid, Lino;Koch, Franziska;Schweizer, Juerg
通讯作者：
Schweizer, Juerg
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.