How to burn storm drain network into DEM as part of hydroconditioning?
Hi All,
Looking for guidance on developing a processing workflow that will allow me to leverage Arc Hydro network tools to hydrocondition a DEM using storm drain infrastructure data.
I have a limited understanding of network analysis in general, so any references or explanations there are appreciated - however, I'm really hoping to get specific suggestions for the following use case:
I have a recent and accurate DEM, and layers of storm drain infrastructure - nodes, pipes, and surface channels. However, many of the surface channels in the layer are creeks and streams, and they are old enough that the lines are not very accurate.
I want to use the DEM to derive new surface channels, as based on preliminary testing those channels are much more accurate - except for where they run into culverts or other stormwater infrastructure features that the DEM doesn't "know" about; then the DEM-derived surface channels go predictably haywire.
For each storm drain network, I want to burn the pipes into the DEM such that DEM-derived channels will follow the network from inlet(s) to outlet. I am struggling with the logic (and processing) of where to get the elevation values I will need to assign to each segment of pipe within a network.
If I understand correctly, Create Breach Lines in not appropriate for this use case as it would create straight lines between points which may not actually follow the storm drain pipes.
Burn Lines into DEM is the tool I have been considering as the most likely candidate, but I have the challenge that some of the intermediate nodes in the storm drain networks are buried nodes, thus (especially in the case of culverts) pulling an elevation value from the DEM for that intermediate node might in fact provide a value higher than the elevation at the top/from/inlet node, preventing the correct flow direction.
I was able to create an Arc Hydro network from my storm drain infrastructure layers, and while there are lots of Midspan Connectivity errors I need to fix, basic Network Tracing seems to work on networks without errors. Are there ways to use network tracing to assign the elevation of the bottom/to/outlet node to the "higher" nodes in the network, so that Burn Lines into DEM can be run to the desired effect? Or to force intermediate nodes to take an elevation value between their upstream and downstream nodes?
Would a different approach be more effective to get my desired outcome?
Thanks in advance for any suggestions, examples, clarifications. Please let me know if the question is not clear!
Examples attached of simple and more complex networks I need to run this on:
