SMS:HEC-RAS

The Hydrologic Engineering Center's (CEIWR-HEC) River Analysis System (HEC-RAS) is a one- and two-dimensional model for computing water surface profiles for steady state or gradually varied flow. HEC-RAS supports networks of channels and is capable of modeling subcritical, supercritical, and mixed flow regime profiles. HEC-RAS is able to model obstructions in the flow path.

The SMS interface to HEC-RAS includes tools for setting up the river networks and cross-sections as well as post-processing capabilities. SMS reads and writes the HEC-GeoRAS GIS import format.

HEC-RAS Simulation

Starting in SMS 12.2, HEC-RAS uses a simulation process. SMS can run multiple HEC-RAS simulations using the same components. To create a new simulation, right-click in the Project Explorer and select New Simulation | HEC-RAS. Components can then be linked to the simulations by dragging the components under the simulation.

Components for the HEC-RAS simulation include the following:

• 2D Mesh

HEC-RAS Simulation Menu

Right-clicking on a HEC-RAS simulation provides a menu with the standard simulation menu commands and the following commands specific to HEC-RAS:

• Model Check – Launches the model checker to look for problems with the simulation setup.
• Export HEC-RAS – Exports the *.rasgeo file containing the mesh information that will be converted during the simulation run.
• Launch HEC-RAS – Brings up the HEC-RAS model wrapper and starts the simulation run. At the end of the simulation run, HEC-RAS will have created a number of output files for use in the HEC-RAS program.
• Save, Export, and Launch HEC-RAS – Completes the processes of saving the SMS project, exporting the HEC-RAS files, and launching the HEC-RAS simulation run.

HEC-RAS Files

A HEC-RAS simulation in SMS can generate a number of files for use in the HEC-RAS program. For following files are generated:

• *.rasgeo – Contains the mesh data generated in SMS. This file is used to generate the other files and must be created before running the HEC-RAC simulation.
• *.g01 – HEC-RAS geometry file.
• *.g01.hdf
• *.prj – The HEC-RAS projection file. For post-processsing, open this file in the HEC-RAS software.

HEC-RAS RASGEO File Example

The RASGEO file contains unit, element, and node information from the mesh component in the HEC-RAS simulation.

RASGEOM_FROM_SMS 10
GridUnit "METER"
Elem 1 2 4 1
Elem 2 2 5 4
Elem 3 4 6 3
Elem 4 4 7 6
Elem 5 7 4 5
Elem 6 6 7 19
Elem 7 6 19 9
Elem 8 7 8 19
Elem 9 20 8 10
Elem 10 8 20 19
Elem 11 22 9 21
...
Node 1 412266.749188 2048559.109411 0.000000
Node 2 412293.104804 2048577.696988 0.000000
Node 3 412206.837470 2048630.299699 0.000000
Node 4 412235.340370 2048594.711214 0.000000
Node 5 412292.972567 2048627.616721 0.000000
Node 6 412234.872220 2048666.466041 0.000000
Node 7 412264.180764 2048663.798224 0.000000
Node 8 412281.643700 2048705.121722 0.000000
Node 9 412214.903435 2048704.060367 0.000000
...

HEC-RAS Troubleshooting

Starting in SMS 12.2, HEC-RAS uses the dynamic model interface. If HEC-RAS was purchased through Aquaveo, the DMI file and HEC-RAS library was included in the installation and should be available for use when starting SMS.

If installing HEC-RAS to an existing version of SMS 12.2 or later, the XML file must be placed in the DynamicXml directory inside the SMS program directory. HEC-RAS also requires a translator. The RAS2D_translator folder should be placed in the Models directory inside the SMS program directory.

SMS needs to know the location of the HEC-RAS executable. If an error appears stating the executable cannot be found, go to Edit | Preferences to open the Preferences dialog. In the File Locations tab, set the HECRAS Translate item to point to the "_runRunGeneric.bat" file in the RAS2D_tranlator.

Related Topics

• SMS Models
• HEC-RAS in WMS

External Links

• HEC-RAS website