CS17A - Concurrent Session 17A: 2D Dam Breach Modeling Best Practices and Troubleshooting

Abstract Description: Dam breach modeling is a common exercise to assist in developing emergency action plans, defining hazard classification, and quantifying risk for dams. HEC-RAS is one of the most popular software applications worldwide for performing dam breach modeling and two-dimensional (2D) methods have become increasingly used (over 1D models) in the industry over the last 10 years. Many modelers run into difficulties when performing 2D dam breach modeling due to inexperience with the software, unfamiliarity with best practices, and not knowing what to do when the model doesn’t behave. At worst, results can be wildly inaccurate and at best, it can be a frustrating and time-consuming endeavor to troubleshoot the modeling issues that are prevalent in 2D dam breach models. In this presentation, the author presents best practices for setting up and executing 2D HEC-RAS dam breach models and provides tips and tricks for troubleshooting through some of the more common problems.

A wide range of practical topics covered in this presentation include determining cell size and orientation, tracking Courant Numbers for optimal time steps, setting up your dam with SA-2D connections, solving initial conditions and submergence issues, determining which shallow water equation set to use, understanding turbulence and when to use it, and using best practices for setting the computation options and tolerances.