Submitted to: Environmental Protection Agency
Publication Type: Proceedings
Publication Acceptance Date: 1/29/1998
Publication Date: N/A
Interpretive Summary: The quality, quantity and timing of runoff from semi-arid rangeland and forested watersheds are crucial for water supply and affect agriculture, fisheries, recreation and hydropower. This project addresses interacting watershed processes over a range of scales in Reynolds Creek Experimental Watershed (RCEW), southwest Idaho, through a spatially distributed modeling framework that accounts for spatial variability in topography, vegetation, and soils to quantify the complete water balance at a range of spatial scales. Model development is proceeding in parallel with the acquisition and processing of remotely sensed data from six aircraft overflights and Landsat. Field data include streamflow, meteorological data, soil moisture and groundwater data, and evapotranspiration flux. Parameterization of snow subgrid variability has focused on causes for this variability and how to model it. A parameterization linking snow-covered area to basin average snow water equivalent shows promise as a tool in scaling the energy balance up model to larger model elements. Different approaches for using remotely sensed imagery to map the spatial distribution of the critical vegetative communities within the watershed are being tested, to allow incorporation of vegetative dynamics into the surface energy flux modeling.
Technical Abstract: Semi-arid rangeland and forested watersheds comprise a large portion of the Western United States. The quality, quantity, and timing of runoff from these watersheds is crucial for water supply and affects agriculture, fisheries, recreation, and hydropower. The purpose of this project is to understand interacting watershed processes over a range of scales in the Reynolds Creek Experimental Watershed (RCEW) in southwest Idaho. The investigators are developing a spatially distributed modeling framework that accounts for spatial variability in topography, vegetation, and soils to quantify the complete water balance at a range of spatial scales. This will provide a framework within which to test hypotheses regarding the hydrology and water balance at Reynolds Creek. This project will lead to a better understanding of the spatial variability and scale dependence of hydrologic processes in RCEW. Because this work is aimed at gaining a better understanding of the physical processes and their interactions, results will be generalizable to other watersheds in the semiarid mountainous Western United States.