topic Re: Drainage Line Processing with ArcHydro in Water Resources Questions

Drainage Line Processing with ArcHydro

UliSchmidt1 — Wed, 13 Jan 2016 14:06:26 GMT

I have to do a flood study for my bachelor thesis with ArcHydro.

And I have a problem using "Drainage Line Processing" after "Stream Segmentation". It doesn't work an the error " Attempted to read or write protected memory. This is often an indication that other memory is corrupt." appears.

Does somebody know what that means and what I can do about it?

Could it be that I have to much Stream Segments, because there are a lot?

Hope someone knows what to do.

Re: Drainage Line Processing with ArcHydro

DanPatterson_Retired — Wed, 13 Jan 2016 14:55:46 GMT

What happens when you use a subset rather than the full set?

Re: Drainage Line Processing with ArcHydro

UliSchmidt1 — Wed, 13 Jan 2016 15:45:14 GMT

What exactly do you mean with subset?

Re: Drainage Line Processing with ArcHydro

MarkBoucher — Wed, 13 Jan 2016 15:51:16 GMT

Uli,

If I were to run into the error you are describing, I would first reboot my PC. If your .mxd is on a network server, I would also move the .mxd and project to a folder with a short simple name onto the local drive (PC or laptop). The move to the local drive reduces errors that might be due to data transfers over the network. The short names (without spaces) reduces errors too, maybe related to some older codes that were made for shorter name strings (couldn't tell you for sure). On the local drive the processing also becomes much faster.

If you haven't check out ArcHydro Problem Solvers, you may find several tips like the ones above to be helpful. I started that thread and others have contributed their questions and answers. You can contribute there too if you find a solution to your problem. You just have to post a link to this thread.

Good luck!

Mark

Re: Drainage Line Processing with ArcHydro

MarkBoucher — Wed, 13 Jan 2016 15:57:04 GMT

Uli,

I think what Dan Patterson means is that you could reduce the number of stream segments. This can be done be increasing the number of cells used to define the streams (part of the stream definition tool). I think the assumption is that this will reduce the processing memory needs and maybe you will get past the error.

Best,

Mark

Re: Drainage Line Processing with ArcHydro

ChadKopplin — Wed, 13 Jan 2016 16:05:24 GMT

Take a look at your task manager to see how much available memory you have before you run the process, then leave it open to see what happens when you try to process, I suspect that you do not have enough memory.

Re: Drainage Line Processing with ArcHydro

UliSchmidt1 — Thu, 14 Jan 2016 10:03:35 GMT

Thank you Mark.

I didn't mind to restart my PC, but unfortunatly it didn't help either.

All my data and the .mxd are already on my local Drive. Maybe the names are too long, i will try it with shorter names.

Thank you, I already checked out "Arc Hydro Problem Solvers". Not just for this problem but for others too.

Thanks

Uli

Re: Drainage Line Processing with ArcHydro

UliSchmidt1 — Thu, 14 Jan 2016 10:07:22 GMT

ok, that was what I thought, bit I wasn't sure.

I tried it with a reduced number of cells, but it didn't work. I had about 90 stream segments.

I will try the suggestion from Chad Bartman

Re: Drainage Line Processing with ArcHydro

UliSchmidt1 — Thu, 14 Jan 2016 10:16:09 GMT

Thanks for the idea. I ran the process while looking at the task manager. But the memory were at 50 % before the process and not much higher during it. I have 3 GB RAM.

Re: Drainage Line Processing with ArcHydro

UliSchmidt1 — Thu, 14 Jan 2016 10:21:06 GMT

I tried with a very high number of cells in stream definition. So there were only 19 Stream Segments. But it didn't help. The same error appeared.

Re: Drainage Line Processing with ArcHydro

MarkBoucher — Thu, 14 Jan 2016 16:14:51 GMT

Uli,

I sounds like the suggested solutions aren't working.

The "Attempted to read or write protected memory" error could mean that you are trying to re-run a process and ArcHydro can't overwrite a certain data file. Have you deleted everything that is created by the ArcHydro process and started fresh? I do this often when I can't determine why the ArcHydro "hits a wall".

Get out of Arc Hydro
Go to the project folders and delete anything the ArcHydro created (geodatabase, raster folder, etc.) - don't delete your agreestream, rawdem, inner/outerwalls, batch points (I export batch points to a shape so I don't have to recreate them: have done that a few times 😕 )
Delete the temp files.

Does this get you past the problem?

Mark

Re: Drainage Line Processing with ArcHydro

UliSchmidt1 — Fri, 15 Jan 2016 09:25:18 GMT

Mark,

what do you mean with "get out of ArcHydro? Close ArcGis? Or must I do something else?

Is deleting anything ArcHydro created the same like starting a whole new project? I already created a new folder and new .mxd and only took the raw data - raw dem and agreestream ( I don't have inner/outerwalls or batch points). But the same error appears. And I already tried the same on another PC, but nothing changed.

Re: Drainage Line Processing with ArcHydro

UliSchmidt1 — Mon, 18 Jan 2016 09:08:43 GMT

I just found out that the name of the Output Drainage Line File must not begin with a number. I named it "_7Drainage" instead of "7_Drainage" and it worked.

But I don't understand why. I started the name of the previous Output files with an number and there wasn't any problem. Can anybody explain that?

Re: Drainage Line Processing with ArcHydro

DanPatterson_Retired — Mon, 18 Jan 2016 11:45:07 GMT

if it was an esri grid.. grid names cannot (shouldn't) begin with numbers and they must be less than 10 (or 13) characters in length and saved to paths without spaces

Re: Drainage Line Processing with ArcHydro

UliSchmidt1 — Mon, 18 Jan 2016 12:48:21 GMT

mhm... the input file was a grid, but the Output from "Drainage Line Processing" should be a vector-file.

The lenght of the name and the paths were correct.

And the names of the previous grids I created with ArcHydro-functions began all with a number. And there wasn't any error like this.

Re: Drainage Line Processing with ArcHydro

DanPatterson_Retired — Mon, 18 Jan 2016 15:31:42 GMT

mysterious... perhaps naming caught up with you

Re: Drainage Line Processing with ArcHydro

MarkBoucher — Wed, 20 Jan 2016 05:24:40 GMT

Sorry. Yes, "get out of Arc Hydro" = "Close ArcGis".

You don't have to create the folders and geodatabases. Arc Hydro will create them. It will also set up other things automatically and this avoids errors. After a while I succumbed to the Arc Hydro default names to save time.