The 2D capability (as well as the 1D) can handle supercritical and subcritical flow, as well as the flow transitions from subcritical

Simplified to very detailed Levee Breach analyses.Simplified to very detailed Dam Breach analyses.Directly connect multiple 2D flow areas with hydraulic structures.Multiple 2D flow areas in the same geometry.Directly connect a 2D flow area to 1D Storage Area with a hydraulic structure.Directly connect 1D reaches into and out of 2D flow areas.Combined 1D channels with 2D flow areas behind levees.Combined 1D channels with 2D floodplain areas.Detailed 2D channel and floodplain modeling.The following are examples of how the 2D flow areas can be used to support modeling with HEC-RAS: The 2D flow areas in HEC-RAS can be used in number of ways.

Users can now perform one-dimensional (1D) unsteady-flow modeling, two-dimensional (2D) unsteady-flow modeling (full Saint Venant equations or Diffusion Wave equations), as well as combined 1D and 2D unsteady-flow routing. “HEC has added the ability to perform two-dimensional (2D) hydrodynamic flow routing within the unsteady flow analysis portion of HEC-RAS. You can get a free electronic copy of the HEC-RAS 2D Modeling User’s Manual here, or by clicking on the link on the side bar to the right. Brunner has done a fantastic job putting together this very well-written document with easy-to-understand instructions and guidance for setting up and running a 2D or combined 1D/2D model in HEC-RAS. If you plan to run a 2D or combined 1D/2D model in HEC-RAS, please read this manual. This manual contains updates to all of the information that was put out in the previous guidance document, “Combined 1D and 2D Modeling using HEC-RAS” as well as more discussion on developing your terrain, creating the 2D mesh, combining with 1D elements, and avoiding errors and instabilities. In advance of the final release of Version 5.0 (hoping for this summer), HEC has released its 2D Modeling User’s Manual, written by Gary Brunner, the HEC-RAS Team Leader.

Hec ras 2d manual