topic Re: Flow accumulation stops at 75% in ArcGIS Spatial Analyst Questions

Flow accumulation stops at 75%

tgossmann — Sun, 06 Nov 2022 14:59:48 GMT

Hello,

I have been trying to create a Flow accumulation raster with input a flow direction raster. I follow the exact steps than provided by many tutorials, but it simply doesn't work. I have read about changing the parallel processing option, but also without success. I've also tried to resample my raster (as it is quite big) but also without success. The flow accumulation tool is running up to 75% in 10min but does never go beyond that even after letting run over 24hours. It's been a week of trial and continuous errors.

I'm working with ArcGIS Pro 2.8 and a DEM of size 58.28 MB.

Any help is much appreciated!
Thanks!

Re: Flow accumulation stops at 75%

DanPatterson — Sun, 06 Nov 2022 18:10:58 GMT

Flow Accumulation (Spatial Analyst)—ArcGIS Pro | Documentation

any loops readily identifiable?

If the input flow direction raster is not created with the Flow Direction tool, there is a chance that the defined flow could loop. If the flow direction contains a loop, Flow Accumulation will go into an endless cycle and never finish.

Re: Flow accumulation stops at 75%

tgossmann — Sun, 06 Nov 2022 18:29:45 GMT

Hi DanPatterson,

I did create the flow direction raster with the Flow Direction tool. How could I know that my flow direction raster contains a loop?

Re: Flow accumulation stops at 75%

DanPatterson — Sun, 06 Nov 2022 21:50:56 GMT

Did you pre-process you DEM? like filling sinks?

Sink (Spatial Analyst)—ArcGIS Pro | Documentation

Re: Flow accumulation stops at 75%

MarkBoucher — Mon, 07 Nov 2022 03:26:42 GMT

I have not worked with Pro. I have had Geoprocesses crash when the project is on a server. But when I put the project on a local drive, the crashing doesn’t happen.