Using Near-Surface Geophysical Methods to Parameterize a Two-Dimensional, Surface-Subsurface Water Flow Model for Mountain Hillslopes
Abstract
Throughout most of the mountain west, snowmelt represents the largest flux of water into local ecosystems in the water year. This snowmelt pulse recharges soil water storage and mountain groundwater systems, provides water for evapotranspiration from local plants, and is transported to larger valley aquifers, rivers, and reservoirs where it is available for many uses. Physically based subsurface water flow models have long been used to predict the timing, magnitude, and routing of this snowmelt pulse into and out of mountain hillslopes and catchments. However, the design and parameterization of such models remains difficult due to the variable nature of the subsurface in mountain environments and the impracticality of direct measurements of subsurface properties at high spatial resolutions. On the other hand, near-surface geophysical methods are non-invasive techniques that can provide continuous, spatially distributed descriptions of subsurface properties. These methods are currently being used to study the geometry, structure, and water dynamics of the shallow subsurface in mountain environments and provide a level of detail not often available with typical hydrogeological methods (e.g. soil pits, boreholes, moisture probes, etc.). In this work, we used the results of shallow seismic refraction and time-lapse electrical resistivity tomography surveys at six headwater catchments in the mountain west with differing geologies to help parameterize and calibrate a physically based, two-dimensional, surface-subsurface water flow model. This model will be used to better understand the geologic controls on hydrologic partitioning of snowmelt at the hillslope scale, identify the dominant flow paths of water at these sites, and determine the necessary model complexity to capture the relevant hydrological processes.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H21H1811P
- Keywords:
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- 1829 Groundwater hydrology;
- HYDROLOGY;
- 1835 Hydrogeophysics;
- HYDROLOGY;
- 1865 Soils;
- HYDROLOGY;
- 1899 General or miscellaneous;
- HYDROLOGY