HR: 1340h
AN: H13B-0405    [Abstracts]
TI: Simulated Streamflow Sensitivity due to Input and Parametric Uncertainty: Spatial Scaling
AU: Georgakakos, K P
EM: KGeorgakakos@hrc-lab.org
AF: Hydrologic Research Center, 12780 High Bluff Drive Suite 250, San Diego, CA 92130 United States
AU: Georgakakos, K P
EM: KGeorgakakos@hrc-lab.org
AF: Scripps Inst Oceanography University of California, San Diego, 9500 Gilman Drive , San Diego, CA 92093 United States
AU: * Carpenter, T M
EM: TCarpenter@hrc-lab.org
AF: Hydrologic Research Center, 12780 High Bluff Drive Suite 250, San Diego, CA 92130 United States
AU: * Carpenter, T M
EM: TCarpenter@hrc-lab.org
AF: Scripps Inst Oceanography University of California, San Diego, 9500 Gilman Drive , San Diego, CA 92093 United States
AB: The influence of rainfall input and parametric uncertainty on the character of the flow simulation uncertainty is examined through ensemble simulations using a validated distributed hydrologic model. The study examines the sensitivity of ensemble flow simulations produced by the distributed model HRCDHM to uncertainty in parametric and radar rainfall input for two study watersheds in the southern Central Plains of the United States. The watersheds were included in the Distributed Model Intercomparison Project (DMIP) organized by the US National Weather Service Office of Hydrologic Development, and HRCDHM validated well in DMIP for both watersheds. Several scales of watershed resolution were employed for both study watersheds, and uncertainty scenarios included parametric uncertainty involving multiple soil model parameters simultaneously, and radar-rainfall uncertainty based on radar-pixel scale uncertainty scale to the subcatchment scale. Flow sensitivities were summarized in terms of a relative measure of the dispersion in the flow ensembles computed for selected events between May 1993 and July 1999. The results consistently show that the flow simulation uncertainty is strongly dependent on catchment scales, with significantly reduced flow sensitivity for larger watershed scales. The consistency of this result for the selected watershed locations may allow for the development of scaling relationships between catchment size and the flow uncertainty measure. Such a relationship potentially may be used to infer pronounced small-scale simulation uncertainties in distributed hydrologic model applications.
DE: 1800 HYDROLOGY
DE: 1854 Precipitation (3354)
DE: 1860 Runoff and streamflow
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting