HR: 0800h
AN: GC41A-0102    [Abstracts]
TI: Modeling the effects of topographic shading on snow-fed runoff with warmer temperatures
AU: * Lott, F
EM: lottf@u.washington.edu
AF: University of Washington, Department of Civil and Environmental Engineering Box 352700, Seattle, WA 98195-2700, United States
AU: Lundquist, J
EM: jdlund@u.washington.edu
AF: University of Washington, Department of Civil and Environmental Engineering Box 352700, Seattle, WA 98195-2700, United States
AB: Discharge in small, tributary streams affects water table heights, riparian vegetation, and habitat in subalpine meadows. Because of this, meadows are very sensitive to the dates when the ephemeral streams go dry. The Distributed Hydrology Soil Vegetation Model (DHSVM) is used in conjunction with a high density hydroclimate monitoring network in the Tuolumne River basin of Yosemite National Park, California to investigate how high elevation sub-basins with different aspects and elevations respond to warmer temperatures. Specifically, this project investigates how topographic shading affects the advance of snowmelt onset and the date snow disappears as temperatures warm. Observations show that in years where the temperature warms earlier in the season, south-facing sub-basins start melting over a week earlier than north-facing basins. Thus, meadow areas fed by sub-basins with southern aspects are expected to be much more sensitive to warming temperatures than areas fed by sub-basins with northern aspects. Traditionally, most future hydrologic simulations are run for large basins and these effects would not be captured. DHSVM is used to test if high- resolution (150 m) modeling with a complete topographic shading component can represent these observed differences and be used to simulate how warmer temperatures will differentially affect various sub-basins and meadow regions.
DE: 1637 Regional climate change
DE: 1813 Eco-hydrology
DE: 1847 Modeling
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting