Hi everybody,
My name is Nils and I am working as a hydrologist in Norway.
I would like to ask you some quite basic questions about cross section interpolations, for example how are you usually importing and interpolating cross sections?
I usually follow these steps:
– Create banks, river, flowpaths and cross sections in GeoHEC-RAS
– Import data in HEC-RAS
– Import bathymetry data as .csv files in HEC-RAS
– Merge cross section data and bathymetry data at every cross section
– Interpolate between cross sections with Cut Line GIS (linear)
The problem is that there are sometimes quite long distances between cross sections. And when I used “Linearly interpolate cut line from bounding XS’s….” the interpolation does not take into account of bank lines. Then I get this results : https://www.dropbox.com/s/rp80qtrqm47t46m/problem.JPG
What is the best way to go around this problem?
Should I define all the cross sections in GeoHEC-RAS? (but then I will only have elevation from the contour lines, and I will not have the possibility to interpolate in HEC-RAS in between cross sections with actual bathymetry data)
Second question:
– I am working now with a project where we only manage to get 15 cross sections for a 6 km long river. The river has a quite flat bed channel. I decided to add additional cross sections as a rectangular channel in the model. Will this cause high instabilities in low/middle flow studies (for unsteady)? Should I represent it as a parabolic channel to avoid this problem?
I hope I did not confuse everybody with my french/norwegian/english.
