Grantee Research Project Results
Hydrologic-Response Simulations for Caspar Creek: A Process-Based Characterization of Cumulative Watershed EffectsEPA Grant Number: U916176
Title: Hydrologic-Response Simulations for Caspar Creek: A Process-Based Characterization of Cumulative Watershed Effects
Investigators: Carr, Adrienne E.
Institution: Stanford University
EPA Project Officer: Boddie, Georgette
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $99,480
RFA: STAR Graduate Fellowships (2003)
Research Category: Fellowship - Geology , Academic Fellowships , Ecological Indicators/Assessment/Restoration
Forest management practices can give rise to cumulative watershed effects (CWEs). The hypothesis to be tested quantitatively in this research project is that timber harvesting can impact hydrologic response. To test this hypothesis, a physically based numerical simulation approach will be employed to characterize quantitatively surface and near-surface hydrologic response in a forested watershed. The overall objective of this research project is to evaluate the effects of improved logging practices on streamflow and sediment production in the second growth forest. The specific objectives of this research project are to: (1) add an interception/throughflow algorithm to the Integrated Hydrology Model (InHM); (2) conduct field measurements/experiments at Caspar Creek (CC) to support the proposed simulation effort; (3) conduct watershed- and catchment-scale simulations of hydrologic response for the North Fork (NF) of CC; and (4) conduct concept-development CWEs simulations of hydrologic response.Approach:
At the heart of this project are a state-of-the-art, physically based hydrologic-response model and a well-characterized experimental watershed that is the site of this ongoing CWE study. InHM simulates three-dimensional (3-D) variably saturated flow in porous media, 3-D variably saturated flow in macropores/fractures, and 2-D flow over the surface and in open channels. InHM is capable of simultaneously simulating Horton and Dunne overland flow, subsurface stormflow, and base flow (groundwater). The field area for this research project is the NF of the CC Experimental Watershed, located within the Jackson State Demonstration Forest in Mendocino County, California. The California Department of Forestry and Fire Protection and the U.S. Forest Service initiated a paired-watershed study at CC in 1962. The simulations will be rigorously evaluated with statistical and graphical criteria. Two important contributions expected from this project are: (1) quantitative assessment of the effects of spatial variability relative to streamflow generation; and (2) quantitative assessment of CWEs at the watershed scale. The numerical experiments will facilitate the quantitative characterization of data-worth relationships as they are related, for example, to future monitoring strategies designed to understand CWEs at the watershed scale.Supplemental Keywords:
fellowship, Caspar Creek, California, CA, cumulative watershed effects, CWEs, forest management practices, timber harvesting, Integrated Hydrology Model, InHM, logging practices, streamflow, sediment production, hydrologic response.