[R-sig-Geo] Spatial interpolation of river network observations

[Facundo Muñoz]

Hi Ultrich,

unfortunately, the approach Tom mentioned accounts for non-Euclidean 
distances, but not for downstream direction, as it asumes stationarity 
and *isotropy* with respect to the hydrologic distances.

In the line of Tom's suggestion, you might be interested in looking at 
the 'soap' R package for smooth interpolation in funny regions.

Bests
ƒacu.-

El 17/11/09 12:45, Tomislav Hengl escribió:
> 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-bounces at stat.math.ethz.ch [mailto:r-sig-geo-bounces at stat.math.ethz.ch] On Behalf
>> Of Ulrich Leopold
>> Sent: Tuesday, November 17, 2009 10:53 AM
>> To: R-sig-geo list; grass-user at 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
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