HR: 16:15h
AN: H54B-02    [Abstracts]
TI: Nonlinear Modeling of Dam-Break Flood Wave Induced Sediment Transport and Morphological Evolution in Rivers
AU: * Tsai, C W
EM: ctsai4@eng.buffalo.edu
AF: State University of New York at Buffalo, 233 Jarvis Hall Department of Civil, Environmental and Structural Engineering, Buffalo, NY 14260 United States
AU: Kuai, K Z
EM: kzheng@buffalo.edu
AF: State University of New York at Buffalo, 233 Jarvis Hall Department of Civil, Environmental and Structural Engineering, Buffalo, NY 14260 United States
AU: Bursik, M
EM: mib@buffalo.edu
AF: State University of New York at Buffalo, 716 NSC Department of Geology, Buffalo, NY 14260 United States
AU: Hess, D
AF: State University of New York at Buffalo, 716 NSC Department of Geology, Buffalo, NY 14260 United States
AB: In this study, we focused on flood wave propagation over a mobile sediment bed after an instantaneous dam breach several characteristic lengths upstream. A nonlinear system of flow and sediment equations is coupled with two closure equations of the bedload transport and frictional channel slope. An exact solution for this water-sediment morphological problem can be obtained through the matched asymptotic perturbation method. The characteristic of both flood wave propagation and bed transients with respect to space and time can then be investigated. The time scale associated with the bed transition, typically believed to be very long compared with the time scale of the water wave, is shown to be close to that of the propagation of the dam-break flood. A clear sediment concentration profile can be found near the wave shock and its effect on the flood propagation will be explored. It is discovered that the sediment concentration and bed scouring reach their maximum values at the wave shock. The perturbations of these three properties (flow depth, sediment concentration, and bed elevation) are subject to dissipation during propagation.
DE: 4558 Sediment transport
DE: 3210 Modeling
DE: 1815 Erosion and sedimentation
DE: 1821 Floods
DE: 1824 Geomorphology (1625)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting