Terri L Arnold/WRD/USGS/DOI
05/20/2008 01:26 PM	To
Michael J Moran/WRD/USGS/DOI@USGS
cc

bcc

Subject
Re: selection of ps loc in NE
	
		
		yeah - I didn't see any obvious reason why I would have screwed up that 
selection. I did it the first time in Arc Workstation, this time I did it 
in ArcGIS.  I selected the wells by PRAQ code again and double checked 
each step against your spreadsheet (which I should have done the first 
time) -- I got them all this time.  I appologize for not getting it right 
the first time. I'll have results for you soon.
		
		-Terri
		
		
---------------------------------------------------------------------------
------------------------
Terri L. Arnold, GIS Specialist
U.S. Geological Survey
National Water-Quality Assessment Program
1201 West University Ave., Suite 100
Urbana, Illinois 61801-2347

tlarnold@usgs.gov, (217) 328-9702

Expressed opinions are my own and not those of the U.S. Geological Survey
		
		
		Michael J Moran/WRD/USGS/DOI
05/20/2008 01:05 PM	
To
Terri L Arnold/WRD/USGS/DOI@USGS
cc

Subject
Re: selection of ps loc in NE
	

	


Terri:

Just a quick note to let you know that I checked my Excel file and 
couldn't find any miss-spellings of the Principal Aquifer field.  Don't 
know what could have happened - maybe something got changed in the import 
into Arc.


Mike


Michael Moran
National Water-Quality Assessment Program
U.S. Geological Survey
1608 Mountain View Road
Rapid City, SD 57702
(605) 394-3244


Terri L Arnold/WRD/USGS/DOI 
05/20/2008 09:40 AM	
To
Michael J Moran/WRD/USGS/DOI@USGS
cc

Subject
selection of ps loc in NE
	

	

Hi Mike.

Ok I experimented a lot with this yesterday.  I can not see any way to get 
30 sites for the aquifers using the equal area option for the site 
selection.  The points are clustered in the aquifers. Dividing the 
aquifers into 30 equal-area cells necessarily means some cells will never 
have any points in them because the cells don't have any wells that could 
be selected. 

I tried using selection with iterating grids but there is a software bug 
in that process that would take me some time to work through. It may be 
possible to get more sites with this process than with the equal area 
method, but I couldn't get the program to complete so I don't know for 
sure.

I can get 30 (or more) sites in each aquifer using the simple random 
selection method and asking that the program exclude wells within a 
certain distance of each other.  I tried an exclusion radius of 500-m 
(since this generally is used for the NAWQA gw networks) and was able to 
get the 30 primary wells and 2 alternates for each primary well. We can 
play with this a little and get more than 30 sites if you want.  If you 
want to try to get enough sites to compare in and out of RFG areas, I 
suggest increasing the number of randomly selected sites for NYNE and 
Glacial (and maybe NACP).   I see 134 of 198 sites in RFG areas for NYNE; 
396/413 for NACP; and 132/152 for Glacial. All wells in the Piedmont and 
Early Mesozoic are in RFG areas so you wouldn't be able to make a 
comparison there.

For the random selection I just tried: For each aquifer there are--
Glacial: 25/30 primary and secondary sites; and 26/30 tertiary sites in 
RFG areas
NACP: 29/30 primary and secondary sites; and 30/30 tertiary sites in RFG 
areas
NYNE: 17/30 primary; 19/30 secondary; and 22/30 tertiary sites in RFG 
areas.

If you want to look at this together on an impromptu webex, we can set one 
up and talk about it while we look.  If you just want to go with this 
method and set of sites, I can send you all the data for the selected 
sites again.

Here are a couple maps to think about:

[attachment "ps_pied.jpg" deleted by Michael J Moran/WRD/USGS/DOI] 
[attachment "ps_nyne.jpg" deleted by Michael J Moran/WRD/USGS/DOI] 
[attachment "ps_nacp.jpg" deleted by Michael J Moran/WRD/USGS/DOI] 
[attachment "ps_meso.jpg" deleted by Michael J Moran/WRD/USGS/DOI] 
[attachment "ps_glac.jpg" deleted by Michael J Moran/WRD/USGS/DOI] 

Here are the selection files from the sample.aml
[attachment "pied_pied.rpt" deleted by Michael J Moran/WRD/USGS/DOI] 
[attachment "nyne_nyne.rpt" deleted by Michael J Moran/WRD/USGS/DOI] 
[attachment "nacp_nacp.rpt" deleted by Michael J Moran/WRD/USGS/DOI] 
[attachment "glac_glac.rpt" deleted by Michael J Moran/WRD/USGS/DOI] 
[attachment "emeso_meso.rpt" deleted by Michael J Moran/WRD/USGS/DOI] 

-Terri

---------------------------------------------------------------------------
------------------------
Terri L. Arnold, GIS Specialist
U.S. Geological Survey
National Water-Quality Assessment Program
1201 West University Ave., Suite 100
Urbana, Illinois 61801-2347

tlarnold@usgs.gov, (217) 328-9702

Expressed opinions are my own and not those of the U.S. Geological Survey

