Modeling Spatial Differences in Snowmelt Runoff Timing

TitleModeling Spatial Differences in Snowmelt Runoff Timing
Publication TypeConference Proceedings
Year of Conference2008
AuthorsLott, F. C., and Lundquist J. D.
Conference Name76th Annual Western Snow Conference
Series TitleProceedings of the 76th Annual Western Snow Conference
Date PublishedApril 2008
PublisherWestern Snow Conference
Conference LocationHood River, OR
KeywordsSubalpine meadows, Yosemite, Tuolumne River, DHSVM, runoff timing, topographic shading

Discharge in small, tributary streams affects water table heights, riparian vegetation, and habitat in subalpine meadows. This project investigates how topographic shading affects the advance of snowmelt onset and the date snow disappears as temperatures warm in Yosemite National Park, California. 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. The Distributed Hydrology Soil Vegetation Model (DHSVM) is used to test if high-resolution (150m) modeling containing a topographic shading component can represent these observed differences in various sub-basins and meadow regions. The findings help define the model complexity needed to properly represent the effects of shading in mountainous terrain.