HR: 08:00h
AN: H11G-01 INVITED    [Abstracts]
TI: Physics-Based Continuous Simulation of Long-Term Near-Surface Hydrologic Response for the Coos Bay Experimental Catchment
AU: * Ebel, B A
EM: bebel32@stanford.edu
AF: Stanford University, Department of Geological and Environmental Sciences, Stanford, CA 94305-2115, United States
AU: Loague, K
EM: keith@pangea.stanford.edu
AF: Stanford University, Department of Geological and Environmental Sciences, Stanford, CA 94305-2115, United States
AU: Montgomery, D R
EM: dave@ess.washington.edu
AF: University of Washington, Department of Earth and Space Sciences, Seattle, WA 98195- 1310, United States
AU: Dietrich, W E
EM: bill@eps.berkeley.edu
AF: University of California Berkeley, Department of Earth and Planetary Science, Berkeley, CA 94720-4767, United States
AB: The study reported here employed the physics-based InHM to simulate continuous hydrologic response from 1990 through 1996 for the Coos Bay (CB1) experimental catchment. InHM dynamically simulates 3D variably- saturated subsurface flow using Richards equation and 2D surface and open channel flow using the diffusion- wave approximation to the depth-integrated shallow-water equations. The uniqueness of the boundary-value problem (BVP) used in a previous study to successfully simulate three sprinkling experiments was assessed, via model performance evaluation against piezometric and discharge data, for 33 events extracted from the seven- year continuous record. The simulations conducted in this effort suggest the potential for interaction between the deeper water table and near-surface hydrologic response, which is in agreement with the detailed field observations made during the CB1 sprinkling experiments. The InHM simulations could not adequately reproduce the observed pore-water pressures, suggesting that detailed characterization of the locations and connectivities of bedrock fractures would be necessary to simulate distributed hydrologic response at locations where bedrock fracture flow is important. The results from this study suggest that uniqueness is a problem for physics-based models when employing a BVP used successfully for smaller magnitude storms to simulate larger storms. The long-term simulations conducted here, combined with previous event-based hydrologic- response simulations and field-based observations, highlight the challenges in characterizing / simulating fractured bedrock flow at small catchments like CB1.
DE: 1804 Catchment
DE: 1826 Geomorphology: hillslope (1625)
DE: 1846 Model calibration (3333)
DE: 1847 Modeling
DE: 1875 Vadose zone
SC: Hydrology [H]
MN: 2007 Fall Meeting