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by (160 points)


I am trying to create a 2D computation model in RiverGis, however, I have issues in creating my 2D mesh. The total area of my DTM is 2.5x3.7 km2 and I defined a computational cell size of 5x5m. My computer takes so long time in no responding. Someone knows if there is a limitation on the 2D mesh size?

Thank you,

Best regards,


1 Answer

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by (3.8k points)
There should be no limit for mesh cells number.

Have you tried to generate your mesh with a much bigger cell size, say 100x100? If not, try that and see if it is possible to work with your input data.
You are right that there should be no limit to the number of mesh cells, however, one of the key things about HEC-RAS 5's mesh is that it captures volume and cell face shape, so it shouldn't be necessary to have such small cells. As long as the cells capture the important aspects of your topography (ridges, especially), and are sufficiently small to get the information you need about the flow field, you should be able to increase the cells size a lot, compared to other 2D models, and still have a good model.
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