topic Re: Gaps in watershed after watershed delineation in ArcGIS Spatial Analyst Questions

Gaps in watershed after watershed delineation

HMort — Mon, 16 Oct 2023 10:53:33 GMT

Hi,

I've been doing a watershed delineation in ArcGIS Pro 3.1.4 from a 50cm DEM. I've done this according to the following workflow: DEM fill, Flow direction (D8), Flow accumulation (D8), placing outlet points and running the watershed tool. Unfortunately, the watersheds that the tool is outputting leaves a couple of gaps where there is no watershed data (and where there is data in the DEM). I can't link an image, but basically it looks like a group of coloured shapes together, where one chunk is missing and you can see whatever's underneath the layer.

Any ideas why this could be and how to deal with it?

Re: Gaps in watershed after watershed delineation

kathy71jones — Tue, 24 Oct 2023 12:51:45 GMT

Sorry, I don't. I'm hoping an expert in this area will help us all out.
Kathy

Re: Gaps in watershed after watershed delineation

HMort — Mon, 22 Jul 2024 11:03:37 GMT

To update this, I basically found that the resolution was too high. This was too computationally expensive for the system I was using to run, causing a lot of noise and the aforementioned gaps.