Drainage Line Processing with ArcHydro

[UliSchmidt1]

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.

[MarkBoucher]

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

[UliSchmidt1]

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.

[MarkBoucher]

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.

[UliSchmidt1]

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?

[DanPatterson_Retired]

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

[UliSchmidt1]

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.

[DanPatterson_Retired]

mysterious... perhaps naming caught up with you