I’m having problems cutting cross sections using the HEC-GeoRAS extension with ArcGIS 10.0.
HEC-GeoRAS will generate “3D” cross sections based on user defined 2D cross sections and a surface tin (or grid) to be imported into HEC-RAS. The problem is that the 3D cross sections generated by HEC-GeoRAS do not follow the 2D cross section lines as one would expect – they (slightly) zigzag about the 2D cross section feature class. As a result, the generated 3D cross sections are longer in length than the actual 2D cross sections, falsely showing too much conveyance area in the HEC-RAS model.
I imported the surface and section lines into ArcGIS from AutoCAD Civil 3D. The surface was imported as a Land xml file.
Does anyone know how to fix this problem? Any help would be appreciated – many thanks!