Hi Martin.
I have succeeded in doing something like that.
Please see http://dx.doi.org/10.1016/j.mcm.2009.05.021.
I used GRASS for the computation of the non-euclidean distances and
modified the geoR library in order to be able to estimate de variograms
and perform kriging prediction with those "customized" distances.
Both the GRASS script for computing distances and the modified geoR
library are open source and available at
http://www.geeitema.org/guenmap/index.jsp?opcion=resultados
I hope it helps.
ƒacu.-
Martin Renner escribió:
Hi All,
I want to kirg fish and seabird densities within an estuary which has several
arms. Since neither organisms cross land, the appropriate distances would not
be euclidian but over-water (as fish swim). There are several papers,
describing this problem and how to deal with it (see below), but I have not
found an easily accessible implementation. Is anybody aware of a solution in R?
Best,
Martin
@article{Rathbun:1998aa,
Author = {Rathbun, Stephen L.},
Journal = {Environmetrics},
Number = {2},
Pages = {109--129},
Title = {Spatial modelling in irregularly shaped regions: kriging
estuaries},
Volume = {9},
Year = {1998}}
@article{Little:1997aa,
Author = {Little, Laurie S. and Edwards, Don and Porter, Dwayne E.},
Journal = {Journal of Experimental Marine Biology and Ecology},
Number = {1},
Pages = {1--11},
Title = {Kriging in estuaries: as the crow flies, or as the fish
swims?},
Volume = {213},
Year = {1997}}
Martin Renner
US Geological Survey
Alaska Science Center
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