flow exist in profile plot but depth doesn’t. + best way to generate flood boundary

[Anonymous]

Hi every one
I have 2 questions
1) as you can see at the picture (see link below) i have water at down face of cell. But when i create profile line and plot water depth there is nothing (0 m), on the flow time series there is some flow visible. Is it because of small depth (0-0.1m)? Or is it a bug?

2) what is the best way to generat flood boundary polygon for situation like this (see second picture – link below). There must be continous flood area, but instead of that, there are cells whit small portion of water (i tried all the renderer options – results are very similar). Is the reducing of the cell size only solution or is there some trick for that?
I think HEC-RAS is perfect solution for me, but this render problem drive me crazy.

thanks for your response. Have a nice day.
pic. 1: https://drive.google.com/file/d/0BzWkBKnv4-QcbVVxMU5FYlFnclE/view?usp=sharing
pic. 2: https://drive.google.com/file/d/0BzWkBKnv4-QcTXZhMmlOdVYwQ2c/view?usp=sharing

[cameron]

Did you look at the table outputs? My guess is the depth is very shallow. Since each cell face is a cross-section, any low spots will allow water to flow into the next cell.

You are correct that the best way to fix the issue for item 2 is to reduce the cell size in this area. You could add some breaklines or do it manually by adding points. There is also other software (SMS as one) that help generate the mesh. The render options don’t change the results and is only for display inside of HEC-RAS.

[Anonymous]

Thanks Cameron. For question 1 >>> yes i looked at the table, there is no value as well. I think water depth value is computing directly from map and flow values is computing for mesh cell during simulation. So there is some differences.

[Author]

Posts