HEC-RAS to TUFLOW

Introduction

This page contains a brief introduction to the methods of converting HEC-RAS model inputs into a format which compatible with TUFLOW. If you have any suggestions to be included in these pages, please email support@tuflow.com.

Model Geometry Conversion

The sdf_to_GIS.exe utility converts HEC-RAS geometric data data into TUFLOW compatible GIS and csv input format. The utility outputs include:

1. Centerline location data in GIS format
2. Cross-section locations in GIS format
3. Cross-section data in csv format

The steps required to use this utility are:

1. Export the HEC-RAS geometry data in sdf format
2. Create a GIS projection file for the conversion
3. Create a batch file to run the utility
4. Double click the batch file in windows explorer to execute the model conversion

Input Data Processing (HEC-RAS)

The HEC-RAS model inputs need to be in SDF format (HEC-RAS export format), and must be geo-referenced using a real world projection.

Export the HEC-RAS sdf file using: File >> Export GIS Data...

Select the following items within the GIS Export window:

• River (Stream) Centerlines
• User Defined Cross Sections
• Entire Cross Section
• Reach Lengths
• Bank Stations
• Levees
• Ineffective Areas
• Blocked Obstructions
• Manning's n

Utility Description

The utility requires GIS projection information to correctly translate the spatial dataset from SDF format to *mif or *.shp format. This is done by including either a projection or header file in the same folder directory as the SDF file. The utility will use the projection information from this file for the data conversion.

1. mif output: Projection.mif or Header.mif
2. shp output: Projection.prf or Header.prj

The following error message will be produced if projection information is not available:

ERROR - A Header.prj or Projection.prj file does not exist in folder

The utility is currently limited to being run using a batch file. To create a batch file, create a new text file in the same location as the sdf file. The name is arbitrary but the file must have the extension ".bat". For example the file name could be "run_sdf_to_GIS.bat". Enter the relevant command syntax to the (refer to the Input Flags table and examples provided below). Double click the batch file in windows explore to execute the model conversion.

Example Syntax (*.mif output)

Description: Convert HEC-RAS sdf data to mif format, trimming cross-section at levee markers (default trim option):

sdf_to_gis.exe -mif hecras_example.sdf

Description: Convert HEC-RAS sdf data to mif format, not trimming cross-section at levee markers:

sdf_to_gis.exe -mif -notrim hecras_example.sdf

Note The above listed syntax assumes that the sdf_to_gis.exe, hecras_example.sdf file and associated batch file are located within the same directory. If not the case, absolute filepath referencing will be required. For example:

C:\TUFLOW\Utilities\HECRAS\sdf_to_gis.exe -mif -notrim hecras_example.sdf

Example Syntax (*.shp output)

Description: Convert HEC-RAS sdf data to shp format, trimming cross-section at levee markers (default trim option):

sdf_to_gis.exe -shp hecras_example.sdf

Description: Convert HEC-RAS sdf data to shp format, not trimming cross-section at levee markers:

sdf_to_gis.exe -shp -notrim hecras_example.sdf

Note The above listed syntax assumes that the sdf_to_gis.exe, hecras_example.sdf file and associated batch file are located within the same directory. If not the case, absolute filepath referencing will be required. For example:

C:\TUFLOW\Utilities\HECRAS\sdf_to_gis.exe -shp -notrim hecras_example.sdf

Input Flags (switches)

A list of the input switches is provided below:

Switch	Description
"-mif"	The output format will be the MapInfo Interchange format (.mif/.mid) recognised by most GIS software
"-shp"	The output format will be the ArcGIS Shapefile format. This can be opened directly in ArcMap, QGIS or SAGA (and most GIS software)
"-notrim	This command will prevent the utility from trimming cross-section data at levee markers. This is a non-default option due to most users converting HEC-RAS creek cross-section data into a TUFLOW 1D compatible format, whilst the surrounding floodplain in 2D areas are modeled in 2D (not requiring HEC-RAS inputs)