The HEC-RAS Export Format is used to export the geometry and structure of a river network to HEC-RAS River Analysis Software. The exported file has a "GEO" extension. More information about the HEC-RAS import format can be found at the US Army Corps of Engineers site (https://www.hec.usace.army.mil/software/hec-ras/)
The exported file includes:
a) Stream Geometry as representated by a series of reaches. Each reach is a 3D terrain feature. It is important that the points in the feature are in downstream ascending order (ie. point i+1 is downstream of point i).
b) Cross Sections Each cross section is a 3D terrain feature. The cross sections are oriented from left - to right (looking downstream). The cross sections exported from upstream to downstream.
NOTE: The cross section feature name is used as a station identifier; it must be numeric only ("100" is a good feature name, "sec 100" is not). It may correspond to stationing along the channel, mile points or any numbering system. HEC-RAS assumes that higher numbers are upstream and lower numbers are downstream.
c) Bank Positions and Reach Lengths Bank positions can be automatically calculated by Terrain, if bank features are included.
Reaches:
Add button
Select a feature to add as a new reach. Feature should be oriented from upstream to downstream (see note above).
Delete button
Delete a reach.
Reach ID
Enter a unique ID for the reach. The default is the feature name.
Stream ID
Enter a unique ID for the stream.
Left Bank
Choose a left bank feature. This feature is used to calculate the bank positionn and reach lengths. If blank the end point of the cross section isused.
Right Bank
Choose a right bank feature. This feature is used to calculate the bank positions and reach lengths. If blank the end point of the cross section isused.
Cross Sections:
Add button
Select one or more features to add as a new cross sections. Cross sections should be ordered from upstream to downstream and oriented from left to right looking downstream (see note above).
Delete button
Delete a cross section.
Station
Enter a unique station for the cross section. The default is the feature name. See not above for HEC-RAS station naming conventions.
