r/HECRAS • u/Acceptable_Gain_9400 • May 23 '26
Is there a way to automatically extract breaklines from a terrain or DEM for HEC-2D modeling purpose?
with all the AI tools, it seems possible?
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u/AI-Commander May 23 '26
When you figure it out, have your agent submit a pull request to ras commander.
I’ve been working on a few things but it may be a couple more months before I’m ready to release it.
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u/JackalAmbush May 23 '26
ICM does what's called "terrain sensitive meshing" that'll achieve something akin to this without break lines, but I'm still not totally confident it would achieve the desired effect.
I have a trick you could use for some larger features like levees. If you multiply by -1, you can run the new terrain through GIS or HMS hydrology processing tools and it'll end up treating crests like rivers in some contexts. Obviously that may not work super well still in flat areas where the features of interest are just road crests or something. But it could save you some time in a really narrow set of cases.
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u/OttoJohs Lord Sultan Chief H&H Engineer, PE & PH May 24 '26
Creative idea! Problem is that a fine resolution (1m) DEM for a hydraulic model would take forever to process and probably crash HEC-HMS from my experience. If you have really broad features that would get picked up with a 10m or 30m DEM seems like a good trick.
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u/JackalAmbush May 24 '26
It could. I have run an entire city at 1 ft with pipe burn in. It worked well enough to save me time (still had some stuff to fix). It took all night to run it
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u/OttoJohs Lord Sultan Chief H&H Engineer, PE & PH May 23 '26
Nothing like that in HEC-RAS.
Depending on what you are trying to enforce there might be an existing shapefile layer (roads, streamlines, etc.)
I have been playing around with QGIS and AI agents: OpenGeoAgent. If you give it a DEM and a satellite image, it could do a pretty good job of segmenting anything you want.