Path that hydrologically connects a point to the nearest element of the drainage netw

[violetmambavioletmamba]

Hey there,

I'm working with a DEM and I need to determine the length of the path that hydrologically connects any cell of the DEM to the nearest element of the drainage network, but cannot find any tools that would be sufficient for this purpose.
I've also looked all over for suggestions online, and the only thing that comes remotely close is the Flow Lenght tool, but it gives the distance between any point in the watershed to the watershed outlet, not the nearest element of the drainage network.

Does anyone have any advice or infofor me?

Thanks, Caterina

[MarkBoucher]

Caterina,

You need to make a hydrologically correct DEM and then create a flow direction grid. After that there are tools for finding what you want. You will need Spatial Analyst.

Arc Hydro (loads with installation of HEC-GeoRAS) has the tools for this, but there are some tools under the Spatial Analyst Tools.tbx\Hydrology.  Maybe the Spatial Analyst Tools.tbx\Hydrology\Flow Length tool would give you what you want.

If you need the trace or length to stop a the drainage network, and you have the drainage network in a polyline format, you can use those polylines to set the direction of the flow direction grid to 255. I believe this will "stop" the distances at the drainage network. I think 255 is  the number for a "sink".

I created this post to "collect" comments on Arc Hydro.
http://forums.arcgis.com/threads/48100-ArcHydro-Problem-Solvers

This post can be found there and has details for the Arc Hydro process. You probably don't need to go past the flow direction step.
http://forums.arcgis.com/threads/53316-Why-can-t-I-define-a-stream-network

Mark