[R-sig-Geo] Kriging

[Robert Helber]

I am attempting to krige a very large 2D region using the geoR package 
(http://cran.ssds.ucdavis.edu/).  The geoR kriging works well for 
regions that have stationary data.  My big region has areas where the 
trend and possibly the variogram changes.  Because of this I am trying 
to split up the big region into smaller regions that have more 
stationary data so that I can krige each region separately.  The problem 
I'm having is that sub-regions that are too small have too little data 
to make a good variogram.  I need to choose the correct size sub-region. 
  My total region is very big and need to automate the process.  Is 
there R software out there that will help with this?  Is there a way to 
choose the size of the subregion in a systematic and logical way?

Thanks.