Project Generation Problem

[Anonymous User]

Original User: USAFAORCapstone

Howdy,
I�??m working towards the creation of a HEC-HMS model for a watershed coming off the Waldo Canyon Burn Scar in Colorado Springs, CO.

We�??ve gone through all of terrain pre-processing but have hit a road block in specifying an outlet point for the project before generating the project. When selecting an outlet point far enough upstream, the contributing area is correctly highlighted but HEC-GeoHMS does not appropriately select the entirety of the upstream area past a certain stream junction (see attached images).

I�??ve read that the issue may be the user-defined threshold was set too high during the stream definition step during pre-processing. Alternatively would it be easiest (or even possible) to use Basin merge to combine the highlighted area?

Please forgive my relative ignorance �?? I�??m an undergraduate Operations Research major with no hydrology of GIS experience.

Thanks!

[MarkBoucher]

When I've seen this happen in other processing, it is the processing extent that gets messed up. I can't tell you how it gets messed up, but you can fix it by going through the Arc Map menus of "Geoprocessing>Environments>Process Extents". Here you choose a layer that has the North/South/East/West extents that you want to make the processing work withing. Either that or put in the N/S/E/W values. The larger the extents, the more time the processing would take, so just use a shape file or raster that defines the area you are working in.

See link below my signature for more tips on using Arc Hydro.