I'm working on a project that involves the calculation of the 50 year flood height so what I am trying to do is create the geometry data in GEO-RAS and export it to HEC-RAS to run the model with the flow I got for that return period. I also got the mean flow. The problem I am having is when I export the data in HEC-RAS everything seems to be right but when I compute the plan the results for the WS Elev doesn't make any sense. I also notice that sometimes HEC-RAS deforms my cross sections not the shape but the length and altitude. It's really weird because if I put a really low flow the floodplain is completely full. Someone could shed light on this? what am I missing? I would much appreciate any help, it's driving me crazy. Attached is the profile of my river with a flow of 18.4 m3/s if it helps.
Many thanks in advance.