Geo-reference HEC-2 Model 1

[HouEng]

I am trying to bring in an older HEC-2 model into RAS and would like to geo-reference the model at the same time. Has anyone done this before, and if so what steps did you take? Also, how close where you able to get the cross section locations to match the model? I have full ArcInfo capabilities at the office and have aerials and other public data to work off of. Any help would be appreciated.

 

[RWF7437]

http://el.erdc.usace.army.mil/elpubs/pdf/smart04-2.pdf

 

[froude]

HouEng,

IF you have the original topographic/hydraulic workmap, you can scale it in CAD (or georectify it in GIS). Once you do this, you will have (very nearly) the geospatial locations of the cross-sections. the coordinates (northing/easting) of each point on the cross section can then be put into the HEC-RAS GIS data editor.

this is just one way of doing it...but may be useless if you don't have the original topographic workmap.

 

[HouEng]

Froude,

I have done exactly that before with another project and worked fairly well for me. The project I am working on now, I do not have the workmap.

 

[froude]

that was my fear! the only other way i could even imagine would be to find some known point, then attempt to measure off the reach lengths, then draw in cross-sections perpendicular to the topo. i can't imagine it would be close, though. good luck! (probably my best advice)

 

[HouEng]

Just to let you’ll know how I located Cross Section Locations. I used the reach lengths to locate cross sections along the stream and vetted the locations based off aerials and structure locations. To find the points in GIS here are the steps I took

1. Digitized Streamline based off DTM and aerials
2. Created a temporary point file to locate point
along the streamline at 1’ intervals (this
took awhile to process for a 8000’ segment stream)
3. Cross Section Locations were pulled from the ID
number for the point. Ex If I needed station 4542 I
would open the point file and find the point ID
4542 This would be the location

This process gave me good results. If anyone has any better ideas please share.