New Approaches to Address Scaling Issues of Water Flow through Snow
Abstract
The dynamic processes that occur during snowmelt create a complex hydrologic environment, where the lateral flow of water has been shown to be significant, but difficult to model. To model this process accurately, representation of snowpack properties and processes at appropriate scales is necessary. This study utilizes new approaches to observe the liquid water content of a snowpack at the plot and hillslope spatial scales, and at sub-daily timescales, to observe the rapid changes that occur during the melt season. This project combined multiple methods including: ground penetrating radar (GPR), LiDAR, lysimeters, and dye tracer experiments. These observations were used to inform the development of a two-dimensional numerical model to simulate the flow of liquid water through the snowpack at the plot scale. Field observations and simulations were collected at three sites in the Colorado Front Range. The sites span a range of elevations and snowpack conditions, including the rain-snow transition zone, treeline, and high alpine environments.
Results of this study show the high spatial and temporal variability in liquid water content of snow that occurs near peak accumulation. Analyzing the multiple approaches displays the correlation between the storage of liquid water in a snowpack and areas of high discharge at the plot scale. Lysimeter results indicate a representative elementary area of 100 m2 at treeline. GPR and LiDAR surveys show similar results at treeline with an increase in area for the high alpine environment by a factor of three. Dye tracer experiments offer insights into the formation of preferential flowpaths in the snowpack, directing meltwater downslope prior to being released. Results of this project display the increased scale of influence that the lateral flow of liquid water has at higher elevations. Two-dimensional simulations of meltwater flow highlight the ability of models to show these differences across elevations, but also the need for improved in situ parameterization of the hydraulic properties of snow layers. Results from this project offer insights towards improving methods of observing snowmelt processes and scaling up efforts to the watershed scale for future investigations.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C41B..04W
- Keywords:
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- 0736 Snow;
- CRYOSPHEREDE: 0740 Snowmelt;
- CRYOSPHEREDE: 0798 Modeling;
- CRYOSPHERE