Hi Ultrich, Facundo Muñoz apparently made a GRASS function to derive distances along streams:
https://stat.ethz.ch/pipermail/r-sig-geo/2009-November/006851.html 17 observations only? That is really tight for any geostatistical analysis (on top, you want to do 3 dimensions!). I would instead consider fitting a smooth surface (splines) / simulating the flow processes. all the best, T. Hengl http://home.medewerker.uva.nl/t.hengl/ > -----Original Message----- > From: r-sig-geo-boun...@stat.math.ethz.ch > [mailto:r-sig-geo-boun...@stat.math.ethz.ch] On Behalf > Of Ulrich Leopold > Sent: Tuesday, November 17, 2009 10:53 AM > To: R-sig-geo list; grass-u...@lists.osgeo.org > Subject: [R-sig-Geo] Spatial interpolation of river network observations > > Dear all, > > I would like to interpolate 17 pollution observations in a storage lake > in 3 dimensions (x,y,z). > > As I understand variogram analysis and kriging are not straightforward > as we are dealing with non-euclidean (hydrologic) distances and > down-stream direction. > > Could someone point me to some algorithms which can roughly estimate the > 3d pollution body accounting for hydrologic distances? > > Attached is a file which shows the sampling locations and the storage lake. > > Thanks very much. > > Best regards, > Ulrich > > > -- > ______________________________________________________________________ > > Ulrich Leopold > > Resource Centre for Environmental Technologies, Public Research Centre > Henri Tudor, Technoport Schlassgoart, 66 rue de Luxembourg, P.O. BOX > 144, L-4002 Esch-sur-Alzette, Luxembourg > > tel: +352 42 5591 618 > fax: +352 42 5591 555 > mobile: +352 691 304813 > http://www.crte.lu , http://www.tudor.lu _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo