Web-Based, Automated Two-Dimensional Dam and Levee Failure Flood Modeling and Mapping

DSS-WISE™ Web is a secure, web-based system with graphical user interface and map server designed to provide automated two-dimensional dam/levee break/breaching modeling and mapping using DSS-WISE™ Lite. This standalone system was developed by the National Center for Computational Hydroscience and Engineering (NCCHE) at the University of Mississippi (UM) with funding provided by the Federal Emergency Management Agency (FEMA) through a sole-source contract. A graphical user interface (GUI) with a map server allows quick and intuitive simulation setup in 12 easy steps that keeps user input to a minimum. All user input is validated in real-time to avoid errors and inconsistencies. The preparation of the input data for the numerical model is fully automated. The computational domain is a DEM, which is cut automatically from the USGS NED with 1/3 arc-second resolution with the user specified cell size that can range from 20 ft to 200 ft. The levees from the National Levee Data database are burned into the DEM at the specified cell size. The Manning’s roughness coefficients are assigned based on the classified land use/cover available from NLCD 2011. The new DSS-WISE™ Lite includes an option to propagate user-specified breach hydrograph over the natural terrain. This option can be used to simulate wet-day dam-break floods (without modeling the reservoir) and levee-breach floods. The finite-volume method is used to numerically solve full dynamic shallow water equations over natural topography, represented by a DEM, using a shock capturing, first-order upwind scheme that handles wetting and drying, captures shocks, and allows mixed regime flows. During the simulation, the inundation extent is displayed at regular intervals on the map server to allow the user to monitor the propagation of the flood. The final results package includes a PDF report, the DEM, raster files of maximum flood depth and arrival time, shape files of inundation extent and simulation setup, csv files of hydrographs at selected cross sections and a KMZ file of the inundation extent. Exceptional computational performance makes DSS-WISE™ Lite an ideal tool for real-time simulation-based emergency response planning. The paper presents the new DSS-WISE™ Lite capability and discusses its computational performance. 19 pp.