HR: 0800h
AN: H11F-0373    [Abstracts]
TI: Use of 2d Hydraulic Models to Predict Stage-Discharge Relationships in Urban Channels
AU: * Ballantine, M R
EM: mballa2@umbc.edu
AF: Department of Geography and Environmental Systems, UMBC, 1000 Hilltop Circle, Baltimore, MD 21250 United States
AU: Miller, A J
EM: miller@umbc.edu
AF: Department of Geography and Environmental Systems, UMBC, 1000 Hilltop Circle, Baltimore, MD 21250 United States
AU: Smith, J A
EM: jsmith@princeton.edu
AF: Department of Civil and Environmental Engineering, Princeton University, E-209 Engineering Quad, Princeton, NJ 08544 United States
AU: Baeck, M L
EM: mlbaeck@princeton.edu
AF: Department of Civil and Environmental Engineering, Princeton University, E-209 Engineering Quad, Princeton, NJ 08544 United States
AB: Small urban watersheds (1-15 km$^{2}$) in the Baltimore metropolitan area with high percent impervious area and extensive storm sewer networks may have very short response time during thunderstorms, with lag to peak as short as 15 minutes for a drainage area of 9.1 km$^{2}$. Under these circumstances it is difficult to establish accurate stage-discharge relationships for stream gages; a field crew may not be able to reach the site in time to make a discharge measurement at high stage, and stage changes so rapidly that a complete measurement at a single stage often is not possible . In order to measure discharge accurately in small urban streams, it is necessary to develop stage-discharge relationships by supplementing direct discharge measurements with hydraulic modeling results for higher flows. In this study a 2d depth-averaged unsteady flow model (TELEMAC-2D; with k-epsilon turbulence closure as recommended by Wilson, et al, 2002) is used in combination with direct discharge measurements to develop stage-discharge rating curves at a series of monitoring sites in the Dead Run watershed. A preliminary working hypothesis suggests that the rating curves are not necessarily single-valued and sometimes exhibit looped or hysteretic behavior that is at least partly dependent on the shape and time base of the hydrograph. Sensitivity of the rating curve to other boundary conditions is also explored.
DE: 1803 Anthropogenic effects
DE: 1821 Floods
DE: 1860 Runoff and streamflow
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting