HR: 09:15h
AN: H21B-05    [PDF]
TI: Affect of Temporal Rainfall Variability and the Width Function on the Peak-Flow Scaling Exponent in the Goodwin Creek Basin
AU: * Furey, P R
EM: furey@cires.colorado.edu
AF: University of Colorado, Cooperative Institute for Research in Environmental Sciences, CB 216, Boulder, CO 80309 United States
AU: Gupta, V K
EM: gupta@cires.colorado.edu
AF: University of Colorado, Cooperative Institute for Research in Environmental Sciences, CB 216, Boulder, CO 80309 United States
AB: Observations show that peak-streamflow scaling exponents change from one rainfall event to another in the Goodwin Creek basin, MS. We develop a space-time equation for streamflows to investigate this phenomenon. The equation is formulated by assuming that rainfall is uniform in space and that the mean rainfall time series for an event is non-stationary. Observations of rainfall from Goodwin Creek support these assumptions. We also assume that channel velocity is constant throughout a basin, meaning there is no channel storage, and that Hortonian overland flow is the only mechanism of runoff generation. It is observed to be the dominant runoff process in Goodwin Creek. Finally, we use the observation that the mean of the width-function maxima are related to spatial scale as a Power Law. With these assumptions, equations are developed for streamflow $Q(n,t)$ and peak streamflow $Q_{p}(n)$, where $t$ is time and $n$ is the number of river network links in a basin and represents spatial scale. The peak flow equation is tested against observed scaling exponents for more than forty rainfall events. Tests show that the equation makes excellent first-order predictions of the observed variability in the peak-flow scaling exponents.
DE: 1821 Floods
DE: 1848 Networks
DE: 1860 Runoff and streamflow
SC: Hydrology [H]
MN: 2003 Fall Meeting