Flow accumulation

[KarynNoyes]

Hi,
I'm running ArcGIS 10, and am trying to create watersheds using newly available LiDAR for my area.  I have a flow direction raster that I've clipped to reduce the size (520MB), and have attempted to create a flow accumulation grid.  I have let it process for days, and the banner at the bottom still scrolls Flow Accumulation...Flow Accumulation...  There is no indication of progress (%).   I don't know if it's actually processing or not.  I have tried this several times now.  Any suggestions?  This is the first of a dozen similar size or larger areas I'll be trying to run.

Thank you,
Karyn
Homer, AK

[KarynNoyes]

After 54 hours, the processing was complete - so now I know that even when there is no indication of the progress in terms of %, it really is working.  I'd delete this thread if I knew how.

[ChristopherBlinn]

Karyn,

Working with the hydrology tools requires a lot of processing.  I had a similar case where I was working with a DEM for the entire state of Kentucky.  I had similar results in terms of processing time.  😞

[PatrickTaurman]

Hi Karyn,

I have heard of a couple reports of it taking a long time for Flow Accumulation.  In ArcMap or ArcCatalog (wherever you are running the Flow Accumulation tool from) you can go to Geoprocessing > Geoprocessing Options and uncheck Enable for Background Processing.  This will cause the tools to use the old dialog box, instead of processing in the background.  I am curious if turning this off allows the Flow Accumulation to process quicker (it should also give you a % complete).

Patrick

[CarlosCanas]

Hi all,
about flow accumulation processing: is it possible to take more than a weekend to process a raster 66 Mb?
I'm having a similar problem since a couple of weeks ago: I do not know the % progress of the flow accumulation tool, it is taking more than what I've worked before for similar areas (Amazon), and I do not know whether to stop it and try it again, or to wait.
Is it ok when the processing is ongoing that arcmap says "NOT RESPONDING"? that is, was is supposed not to be able to make any other work while this tool is running?

please, all help will be appreciated.
thanks!

[CharlesWentzel]

I began processing a flow direction grid of just under 500megs early yesterday afternoon and over 18 hours later it was still running when I got into work this morning (to my surprise since I have a brand new, souped up machine).  I was going to terminate the process but then thought I'd check around first to see if others had the same problem.  After read this, I'm just going to let the process run all weekend (thankfully it is Friday).  I'm going to be turning off all auto-updates right now so I don't get auto-rebooted right out of the process and have to start over.  I'll post after the weekend how it went.

[CharlesWentzel]

I began processing a flow direction grid of just under 500megs early yesterday afternoon and over 18 hours later it was still running when I got into work this morning (to my surprise since I have a brand new, souped up machine).  I was going to terminate the process but then thought I'd check around first to see if others had the same problem.  After read this, I'm just going to let the process run all weekend (thankfully it is Friday).  I'm going to be turning off all auto-updates right now so I don't get auto-rebooted right out of the process and have to start over.  I'll post after the weekend how it went.

I let the process run for over a week before I terminated it.  I'm not sure it was working or not, but I got tired of waiting.  I really wish there were some sort of progress bars for these time consuming processes in Arc so one could tell if it was actually working or not.

[LornaMurison]

Using ArcGIS 9.3.1 I've had to create flow accumulation grids from flow direction grids ranging from 150ish to 230ish megs.  The processing time for these was measured in days or weeks, never hours.
This is using ArcHydro.

[TadGoetz]

edit: data was incorrect.  Sorry.