I have a vector layer containing the potential drainage lines that have been computed from a DEM. I want to be able to click on any point and identify all the lines that are connected to my point of interest. In effect, this means identifying all the streams that contribute water to the point.

I am sure this is not a novel problem. It would be similar to identifying all electric lines/houses that get power from a particular sub-station and other real life problems. I just can't seem to phrase my problem just right to get the correct response from Google.

I understand that a simple identification of all connected lines would not take care of upstream and downstream drainages. I guess that will have to figured out later.

  • What software would you like to do this in? – Nathan W Aug 14 '13 at 6:12
  • Network analysis is the word you are looking for. – Nathan W Aug 14 '13 at 6:13
  • I would preferably like it to work with ArcGIS. I am trying to get this to work in a web application through ArcGIS Server 9.3. I looked 'Network Analysis' tools in ArcGIS up, but I can't find a tool that might help me with my problem – Gaurav K Aug 14 '13 at 6:30

If you use ArcHydro tools (assuming you have access to Arcmap) and follow one of the suggested (partial) workflows here, you should be able to use the button Point delineation. That will give you the catchment area that contributes to any point in the DEM.

A Select by location should then get you the relevant drainage lines.

| improve this answer | |
  • Thanks for your response. The drainages have been created from the DEM following exactly the same procedure. Identifying the catchment area from DEM is realistic for a small watershed but I want it to be available as an online tool for a very large area. Ergo my need for just identifying the connected drainages. – Gaurav K Aug 14 '13 at 6:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.