Idea for Enhancement to Flow Direction

[StevenLevine]

Saw a presentation (virtually) by Emma Rosenthal at the UC where she was mapping potential flow of lava. In the presentation, she set points and then clicked on one to give angle of flow at that point, or something like that. I used to work in Emergency Management and can see where this could be extremely useful to demonstrating to higher-ups the potential of aerial, or even flash flooding based on flood modeling. The enhancement I have (I contacted Emma after the conference and she doesn't think this is currently possible) is that, when you click to set each point, such as the low areas on a topographical map, that ArcGIS should be able to automatically calculate the flow direction from one point to the next so the map creator doesn't have to enter that information manually after entering the points... or even create a tool such as "Set Flow Direction" where you can either click existing points or set points and it calculates automatically. Especially if flow animation can be added, choosing like "Water", "Lava", "Toxic Gas" or "Oil" for example. Maybe this already exists in flood modeling capabilities? Not sure, but would make what she demonstrated be a bit easier IMHO. Thank you for the consideration! - Steve Levine

[KoryKramer]

You could run the https://pro.arcgis.com/en/pro-app/latest/tool-reference/spatial-analyst/derive-stream-as-line.htm tool on your DEM to give you the flow lines. If the ultimate goal is for something like flood modeling, note that in the ArcGIS Pro Roadmap we have "simulation modeling" -Simulate complex phenomena like airflow and fluid dynamics in 3D/4D based on physical models. This of course will go far beyond dropping a point on a map to show the direction water would flow at a single point.

Here's a quick example of running the Derive Stream as Line tool and symbolizing the output lines with arrow markers. Maybe that helps?