Influence of Hydrogeologic Structure on the Hillslope Groundwater Dynamics in a Mountainous Watershed
Abstract
Groundwater flow in mountainous watersheds plays a critical role in water resources, controlling streamflow throughout dry periods, geochemical dynamics, and water quality. Given the lack of direct borehole measurements, assumptions about the spatial variability of flow properties must be employed when modeling groundwater flow. Some assumptions, such as exponentially decaying permeability, are often used to parameterize but may not be hydrogeologically realistic, leading to inaccurate models. On the other hand, detailed subsurface characterization aided by geologic and geophysical data may improve model accuracy but can be prohibitively costly. In this work, we evaluate several hydrogeologic representations and parameterizations by quantifying how accurately they can reproduce hydrological and geophysical data simultaneously. We demonstrate this approach using water level and electrical resistivity tomography data collected in a mountainous watershed in western Colorado. We organize the subsurface parameterizations by how hydrogeologically realistic they are, and use Bayesian methods to discuss how much geological reality is required to fit hydrological observations, while honoring the geophysical data. This type of analysis will provide insights on what degree of subsurface characterization is needed to accurately predict groundwater dynamics.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H32A..05M