Water Stewardship Information Sources

ID 1782
Citation Thyer, M, Beckers, J, Spittlehouse, D, Alila, Y and Winkler, R. 2004. Diagnosing a distributed hydrologic model for two high-elevation forested catchments based on detailed stand- and basin-scale data. Water Resources Research 40, W01103, doi:10.1029/2003WR002414.
Organization FLNRO
URL http://onlinelibrary.wiley.com/doi/10.1029/2003WR002414/pdf
Abstract/Description or Keywords This study evaluates the performance and internal structure of the distributed
hydrology soil vegetation model (DHSVM) using 1998-2001 data collected at Upper
Penticton Creek, British Columbia, Canada. It is shown that clear-cut snowmelt rates
calculated using data-derived snow albedo curves are in agreement with observed
lysimeter outflow. Measurements in a forest stand with 50% air crown closure suggest that
the fraction of shortwave radiation transmitted through the canopy is 0.18-0.28 while the
hemispherical canopy view factor controlling longwave radiation fluxes to the forest
snowpack is estimated at 0.81 ᄆ 0.07. DHSVM overestimates shortwave transmittance
(0.50) and underestimates the view factor (0.50). An alternative forest radiation balance is
formulated that is consistent with the measurements. This new formulation improves
model efficiency in simulating streamflow from 0.84 to 0.91 due to greater early season
melt that results from the enhanced importance of longwave radiation below the canopy.
The model captures differences in canopy rainfall interception between small and large
storms, tree transpiration measured over a 6-day summer period, and differences in
soil moisture between a dry and a wet summer. While the model was calibrated to 1999
snow water equivalent (SWE) and hydrograph data for the untreated control basin, it
successfully simulates forest and clear-cut SWE and streamflow for the 3 other years and
4 years of preharvesting and postharvesting streamflow for the second basin. Comparison
of model states with the large array of observations suggests that the modified model
provides a reliable tool for assessing forest management impacts in the region. INDEX
TERMS: 1803 Hydrology: Anthropogenic effects; 1818 Hydrology: Evapotranspiration; 1860 Hydrology:
Runoff and streamflow; 1863 Hydrology: Snow and ice (1827); 1866 Hydrology: Soil moisture; KEYWORDS:
snow, radiation, evaporation, soil moisture, streamflow, DHSVM
Information Type article
Regional Watershed Okanagan
Sub-watershed if known Penticton Creek
Aquifer #
Comments
Project status complete
Contact Name Younes Alila
Contact Email [email protected]