HR: 1340h
AN: H33C-0480    [Abstracts]
TI: Distributed snow modeling suitable for use with operational data for the American River watershed.
AU: * Shamir, E
EM: eshamir@hrc-lab.org
AF: Hydrologic Research Ceenter, 12780 High Bluff Drive, Suite 250 , San Diego, CA 92130
AU: Georgakakos, K P
EM: KGeorgakakos@hrc-lab.org
AF: Hydrologic Research Ceenter, 12780 High Bluff Drive, Suite 250 , San Diego, CA 92130
AB: The mountainous terrain of the American River watershed (~4300 km2) at the Western slope of the Northern Sierra Nevada is subject to significant variability in the atmospheric forcing that controls the snow accumulation and ablations processes (i.e., precipitation, surface temperature, and radiation). For a hydrologic model that attempts to predict both short- and long-term streamflow discharges, a plausible description of the seasonal and intermittent winter snow pack accumulation and ablation is crucial. At present the NWS-CNRFC operational snow model is implemented in a semi distributed manner (modeling unit of about 100-1000 km2) and therefore lump distinct spatial variability of snow processes. In this study we attempt to account for the precipitation, temperature, and radiation spatial variability by constructing a distributed snow accumulation and melting model suitable for use with commonly available sparse data. An adaptation of the NWS-Snow17 energy and mass balance that is used operationally at the NWS River Forecast Centers is implemented at 1 km2 grid cells with distributed input and model parameters. The input to the model (i.e., precipitation and surface temperature) is interpolated from observed point data. The surface temperature was interpolated over the basin based on adiabatic lapse rates using topographic information whereas the precipitation was interpolated based on maps of climatic mean annual rainfall distribution acquired from PRISM. The model parameters that control the melting rate due to radiation were interpolated based on aspect. The study was conducted for the entire American basin for the snow seasons of 1999-2000. Validation of the Snow Water Equivalent (SWE) prediction is done by comparing to observation from 12 snow Sensors. The Snow Cover Area (SCA) prediction was evaluated by comparing to remotely sensed 500m daily snow cover derived from MODIS. The results that the distribution of snow over the area is well captured and the quantity compared to the snow gauges are well estimated in the high elevation.
DE: 1821 Floods
DE: 1833 Hydroclimatology
DE: 1860 Runoff and streamflow
DE: 1863 Snow and ice (1827)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting