Watershed for a linear feature

[JyotiRohodia]

Hi All,

Is it possible to create a watershed for a linear feature instead of pour points.

MAIN GOAL:

The purpose is the identify primary and secondary watershed/basins along important road lines.

MY WORKFLOW:

I thought to create primary watershed using the pour points  along the roadline and then erase these watershed features from the watershed created along the entire roadline to get secondary watershed/basin.

I don't know if my logic is making sense. If any one has any idea about creating primary and secondary basins, it would be highly appreciated.

Thanks,

Jyoti

[MarkBoucher]

Here is a possible process. I won't detail how to do every step here, but they should be doable.

1. Use ArcHydro to create catchments with drainlines, etc.
2. Intersect the line represending the road with the DrainageLine layer (results would be points). Create a field in this point feature class called "Name". (For later coping the HydroID of the drain lines to the to the "Name" field in BatchPoint layer.)
3. Using the points extract the value of the flow accumulation (fac) raster to another field. The fac represent the number of upstream grid cells. Maybe calculate the watershed area that fac represents in another field (fac value x (grid cell dimention)^2)
4. Create one random BatchPoint (to be deleted later) to set up the BatchPoint feature class .
5. Select the points by the size of watershed (fac value x (grid cell dimention)^2) to reduce the number of points to include only those watersheds big enough to concern you.
6. Copy the selected points to that BatchPoint shape file. The"Name" field should be fill in with the values in the "Name" field of the points copied in.
7. In the attribute table, for BatchPoint, calculate the BatchDone, SnapOn, SrcType fields as needed (normally 0,1,0 and Outlet, respectively).
8. Use the BatchPoint layer to create watersheds for these key points along the road.
9. The "Name" should show up in the resulting Watershed layer.

Hopefully this process or something like it will work for you.

Mark