Use Survey Data in HEC-GeoRas

[hecfan]

Hello Everyone,

I created geometric data from ArcGIS (or more precisely, Hec-GeoRAS). The elevation model is based on the data with an accuracy of 10 meter in elevation, which is apparently not sufficient for a channel of maximum 15 meters. So our survey crew conducted a survey using total station. Therefore all are geo-referenced.

I got a shape file containing all the survey points. I want to using the survey data to build x-sections while planning to do flood mapping in ArcGIS. My question is whether I should modify the x-sections after importing the geometry data from Hec-GeoRAS or should I modify the digital elevation model (DEM) in ArcGIS first then build the geometry model using the updated DEM. For the first option, I am concerned with the compatiblity of the two elevation data. As I modify the elevation data in Hec-RAS, can I import the modified data back to ArcGIS with no serious problem? For the later option, I want to know how to update the DEM at the local area where the accurate survey data is available.

Any suggestion or insight is appreicated!

Sincerely,

HECFAN