topic Re: River Slope Errors in Water Resources Questions

River Slope Errors

Eng_A_SH — Wed, 14 Jul 2021 23:56:33 GMT

Greetings.

I'm using a Geographic Coordinate System ( WGS84 ). And i've used an SRTM DEM while using the hecgeo HMS extension on ArcMap. I've got all the way to [ Characteristics ] > [ River Slope ] and it showed me this error.

I tried fixing it by adding a Z factor of 1 - Which is the default - by using [ 3D analyst ] > [ Slope ].

I named the result WatershedFactor1

This error showed up :

Would appreciate the help.

Thank you.

Re: River Slope Errors

Anonymous User — Thu, 15 Jul 2021 00:52:44 GMT

Hi @Eng_A_SH ,

you can disable the back-end process and run the processes in the foreground of ArcGIS Map,

Here is a link that can help you with the disabling process.

ArcGIS Help 10.1 - Foreground and background processing

Re: River Slope Errors

Eng_A_SH — Thu, 15 Jul 2021 01:20:49 GMT

Hi @Anonymous User .
Thanks for the response. Unfortunately this did not work out.
The following error screen appears :

Re: River Slope Errors

Anonymous User — Thu, 15 Jul 2021 01:33:05 GMT

Hi @Eng_A_SH ,

Can you have a look at what the DEM Georefence is, is it referenced?

Re: River Slope Errors

Eng_A_SH — Thu, 15 Jul 2021 01:52:21 GMT

Hi @Anonymous User .

These are the properties of the RawDEM layer

Re: River Slope Errors

DeanDjokic — Thu, 15 Jul 2021 05:54:55 GMT

Unfortunately, GeoHMS tools do not manage data in GCS. While most tools will work with it (e.g. terrain preprocessing and subbasin delineation), once you get into calculation of stream and watershed characteristics, GCS is not supported. There are workarounds, but you are better off projecting the DEM and starting from scratch (you cannot just project all raster derivatives).

Re: River Slope Errors

rcepol — Mon, 16 Mar 2026 19:17:12 GMT

I have same problem. Was it already solved? I already projected the dem and stream, but still i get error in river slope. anybody can help