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GEOSTATS: Impact on kriging variance ?

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  • Gregoire Dubois
    Dear all, I posted two months ago a question for which I didn t receive any answer. Was the answer too obvious or my question stupid ? Here is a second try. A
    Message 1 of 2 , Dec 8, 1905
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      Dear all,

      I posted two months ago a question for which I didn't
      receive any answer. Was the answer too obvious or my
      question stupid ? Here is a second try.

      A common practice in geostatistics is to use only
      a limited number of points to make the estimations
      in order to take more local effects into account. However,
      the modeling of the semivariogram is made on the
      whole data set. My question is: what is the impact
      of the use of a limited number of points on the kriging
      variance (which should be affected by such a procedure) ?
      Any references ?

      I will summarize

      Best regards

      Gregoire


      Gregoire Dubois
      Section of Earth Sciences
      Institute of Mineralogy and Petrography
      University of Lausanne
      Switzerland

      Currently detached in Italy

      http://curie.ei.jrc.it/ai-geostats.htm

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    • Hagues
      Dear all, Gregoire posted a question regarding using a limited number of points to make estimations in order to take more local effects into account . I am
      Message 2 of 2 , Apr 11, 2000
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        Dear all,

        Gregoire posted a question regarding using a "limited number of points to
        make estimations in order to take more local effects into account".

        I am not too sure if this response is relevant but there was a study
        presented by Danie Krige (1997) which looked at the problem of trying to
        reduce the inherent smoothing of kriging by reducing the number of data
        points used to derive an estimate.

        The process of reducing the number of data points to derive an estimate
        resulted in conditional biases in the results. Danie's conclusions were
        that to avoid conditional biases one had to use a suitable number of points
        to derive the estimates, but at the same time accept the unavoidable fact
        that the resultant estimates will always be accompanied by some smoothing.

        Reference

        KRIGE, D.G.; 1997: Block kriging and the fallacy of endeavouring to reduce
        or eliminate smoothing. Proceedings of the 2nd Regional APCOM Symposium on
        Computer Applications and Operations Research in the Minerals industries,
        Moscow.

        Hope this helps.

        Richard Hague


        -----Original Message-----
        From: Gregoire Dubois <gregoire.dubois@...>
        To: ai-geostats@... <ai-geostats@...>
        Date: Thursday, 6 July 2000 6:31
        Subject: GEOSTATS: Impact on kriging variance ?


        >Dear all,
        >
        >I posted two months ago a question for which I didn't
        >receive any answer. Was the answer too obvious or my
        >question stupid ? Here is a second try.
        >
        >A common practice in geostatistics is to use only
        >a limited number of points to make the estimations
        >in order to take more local effects into account. However,
        >the modeling of the semivariogram is made on the
        >whole data set. My question is: what is the impact
        >of the use of a limited number of points on the kriging
        >variance (which should be affected by such a procedure) ?
        >Any references ?
        >
        >I will summarize
        >
        >Best regards
        >
        >Gregoire
        >
        >
        >Gregoire Dubois
        >Section of Earth Sciences
        >Institute of Mineralogy and Petrography
        >University of Lausanne
        >Switzerland
        >
        >Currently detached in Italy
        >
        >http://curie.ei.jrc.it/ai-geostats.htm
        >
        >____________________________________________________________________
        >Get free email and a permanent address at http://www.netaddress.com/?N=1
        >--
        >*To post a message to the list, send it to ai-geostats@....
        >*As a general service to list users, please remember to post a summary
        >of any useful responses to your questions.
        >*To unsubscribe, send email to majordomo@... with no subject and
        >"unsubscribe ai-geostats" in the message body.
        >DO NOT SEND Subscribe/Unsubscribe requests to the list!
        >

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