SLAMM Forum

General Category => Using SLAMM => Topic started by: Dean on August 24, 2009, 03:09:11 PM

Title: impervious data and dryland class
Post by: Dean on August 24, 2009, 03:09:11 PM
I understand that the impervious input is used to define developed (>25%) vs undeveloped dryland (<25%).  However, I can't tell if this is happening from the model outputs, b/c there are no statistics in the Excel output for changes in these.  I would expect some undeveloped dryland (2) to be lost.  I am running the model with Protect Developed checked ON.

Do I understand it correctly that the NWI input file should have no category 1 or 2, but that they are derived from the imp.txt file?  How can I be sure this is working?  I'm using impervious data from the Georgia Land Use Trends, b/c it's from 2005. My cell size matches the DEM, and is in integer form (though I've tried floating point and integer). 

Does the file name matter?  I've tried both filename_imp.txt and filenameimp.txt?

Any suggestions or hints would be great.

Thanks!
Dean
Title: Re: impervious data and dryland class
Post by: Jonathan S. Clough on August 24, 2009, 03:18:04 PM
The NWI input file actually needs to have category "1" or "2" to determine where the upland (dry-land) and wetland boundary exists.  If you know the developed and undeveloped boundaries, the model can be input with spatially variable "1"s and "2"s depending on what is developed or undeveloped.  Otherwise you can input all 1s and all 2s and use an _imp.txt file to produce the developed, non-developed boundaries.

The file name may matter, (at one point I made it accept either form but I don't know if that's part of the latest distributed executable or not).  Try filename_imp.txt first.  You should see a map that has bright red for undeveloped land and dark maroon red for developed land. 

Good luck and let me know if you have further questions.  -- J