Authors: Jani Fathima Jamal, Shivakumar Balachandran, Ezzat Elalfy, Jasim Imran, Enrica Viparelli, Hanif Chaudhry, Erfan Goharian– University of South Carolina
Title: Incorporating an efficient dynamic routing model for rivers to predict dam break flows during floods
Abstract: The hydraulic module of the National Water Model (NWM) uses a one-dimensional diffusion wave formulation, or Muskingham routing method, for simulating flood flows in a river network. Dynamic modeling, however, is crucial for accurate predictions of flood flows and flow interaction with hydraulic structures in real-life problems. This need is even stronger in the presence of dam break and/or levee breach within the network, when embankment failure exacerbates flooding. One- or two-dimensional unsteady flow models can be suitably chosen to simulate flow features in river networks. The modeling approach is chosen according to the complexity of the network, river bathymetry, and flow conditions. In the next generation model framework, a 1D dynamic modelling approach will be adopted for flood routing. The proposed 1D model will solve the Saint-Venant equations using the four-point Preissmann implicit finite difference scheme. An iterative prediction and correction algorithm based on water stages at channel junctions will be implemented for efficient solution of flow hydraulics, considering the back water effect at the junctions. Data available from the literature will be used for model validation. Model extension to explicitly account for impacts of embankment failure will be done by integrating the 1D model with suitable dam-break and levee breach models.