Re: [ai-geostats] problem of spatial continuity of groundwater head

2004-11-23 Thread Isobel Clark
Kai

I would suggest you take a look at:

Introduction to Geostatistics: Applications in
Hydrogeology (Stanford-Cambridge Program)  
P. K. Kitanidis 

which is a great base to work from.

Isobel
http:///geoecosse.bizland.com

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RE: [ai-geostats] problem of spatial continuity of groundwater head

2004-11-23 Thread Colin Daly
Title: problem of spatial continuity of groundwater head





 Kai
 
There has been some work in this area
 
there are some references at the Ecole des Mines, Centre de Geostatistique 
website  see the papers by Anne Dong and Chris Roth to start with
 
http://www.bib.ensmp.fr/cgi-bin/pubinterro?mots=geostatistique
 
Not all of these are published outside the center - but some are .for 
example Anne's 1988 paper (in English) was in the Avignon Geostats 
Conference and the reference is given at the site above
 
Interesting area ...good luck!
 
 
Regards
 
Colin

  -Original Message- From: 
  [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
  Sent: Tue 11/23/2004 12:16 PM To: [EMAIL PROTECTED] 
  Cc: Subject: [ai-geostats] problem of spatial continuity 
  of groundwater head
  Hello list, 
  A few days ago I had a discussion about spatial 
  continuity of hydraulic heads and the following question: Is it allowed to use 
  a krging technique for this variable?
  First Opinion: there are different processes which 
  influence the groundwater heads, e.g.: 
      - gravity (hydraulic gradient) 
      - 
  grounwater recharge     
  - anthropogenic influence (pumping/injection) 
  So there is a global trend which is overlayed from 
  different additional trends like groundwater recharge and anthropogenic 
  influence (pumping/injection) and you canÂt seperate these processes. These 
  are the reasons that you get problems with the 
  ergodicity and it is not possible to use kriging techniques, because you 
  havenÂt a spatial continuity which is based on 
  one process.
  Second Opinion: There is a basic process for the 
  groundwater heads (the movement based on the Darcy law and thatÂs it) . There 
  exist a global trend (but you can handle it with Universal kriging) and the 
  differences depend on the other processes maybe give you another trend by 
  large scale problems (and then you have problems with the ergodicity and have 
  to use moving window statistics to divide you working area). So you have a 
  spatial continuity which is not necesseraly influenced by problems with 
  ergodicity and you can use kriging techniques. Maybe the anthropogenic 
  influence could be a process which disturb the spatial continuity.
  I know itÂs quite a hydrogeology problem but anyway 
  I would like to hear your opinion or experiences on that topic. 
  Looking forward to the answers, 
  Kai 
  Dipl. Kai ZoÃeder Bayerisches Geologisches Landesamt HeÃstr. 128 D-80797 MÃnchen Tel.: 089-9214 
  2655 
  http://www.bayern.de/gla 
  http://www.bis.bayern.de 
  


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[ai-geostats] problem of spatial continuity of groundwater head

2004-11-23 Thread Kai.Zosseder
Title: problem of spatial continuity of groundwater head






Hello list,


A few days ago I had a discussion about spatial continuity of hydraulic heads and the following question: Is it allowed to use a krging technique for this variable?

First Opinion: there are different processes which influence the groundwater heads, e.g.: 

    - gravity (hydraulic gradient)

    - grounwater recharge

    - anthropogenic influence (pumping/injection)

So there is a global trend which is overlayed from different additional trends like groundwater recharge and anthropogenic influence (pumping/injection) and you can´t seperate these processes. These are the reasons that you get problems with the ergodicity and it is not possible to use kriging techniques, because you haven´t a spatial continuity which is based on one process.

Second Opinion: There is a basic process for the groundwater heads (the movement based on the Darcy law and that´s it) . There exist a global trend (but you can handle it with Universal kriging) and the differences depend on the other processes maybe give you another trend by large scale problems (and then you have problems with the ergodicity and have to use moving window statistics to divide you working area). So you have a spatial continuity which is not necesseraly influenced by problems with ergodicity and you can use kriging techniques. Maybe the anthropogenic influence could be a process which disturb the spatial continuity.

I know it´s quite a hydrogeology problem but anyway I would like to hear your opinion or experiences on that topic.


Looking forward to the answers,


Kai


Dipl. Kai Zoßeder

Bayerisches Geologisches Landesamt

Heßstr. 128

D-80797 München

Tel.: 089-9214 2655


http://www.bayern.de/gla

http://www.bis.bayern.de






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