ASTM_D_5923_-_96_2010.pdf

Designation:D592396(Reapproved 2010)Standard Guide forSelection of Kriging Methods in Geostatistical SiteInvestigations1This standard is issued under the fixed designation D5923;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONGeostatistics is a framework for data analysis,estimation,and simulation in media whosemeasurable attributes show erratic spatial variability yet also possess a degree of spatial continuityimparted by the natural and anthropogenic processes operating therein.The soil,rock,and containedfluids encountered in environmental or geotechnical site investigations present such features,and theirsampled attributes are therefore amenable to geostatistical treatment.Kriging methods are geostatis-tical techniques for spatial estimation belonging to the class of least-squares estimators.This guidereviews criteria for selecting a kriging method,offering direction based on a consensus of viewswithout recommending a standard practice to follow in all cases.1.Scope1.1 This guide covers recommendations for selecting appro-priate kriging methods based on study objectives,exploratorydata analysis,and analysis of spatial variation.1.2 This guide considers commonly used forms of kriging,including ordinary kriging,simple kriging,lognormal kriging,universal kriging,and indicator kriging.Multivariate,space-time,and other less-frequently used kriging methods are notdiscussed;however,this is not intended to reflect any judge-ment as to the validity of these methods.1.3 This guide describes conditions for which kriging meth-ods are not appropriate and for which geostatistical simulationsapproaches should be used.1.4 This guide does not discuss non-geostatistical alterna-tives to kriging,such as splines or inverse-distance techniques.1.5 This guide does not discuss the basic principles ofkriging.Introductions to geostatistics and kriging may befound in numerous texts including Refs(1-3).2A review ofkriging methods is given in Ref.(4).1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 This guide offers an organized collection of informationor a series of options and does not recommend a specificcourse of action.This document cannot replace education orexperience and should be used in conjunction with professionaljudgment.Not all aspects of this guide may be applicable in allcircumstances.This ASTM standard is not intended to repre-sent or replace the standard of care by which the adequacy ofa given professional service must be judged,nor should thisdocument be applied without consideration of a projects manyunique aspects.The word“Standard”in the title of thisdocument means only that the document has been approvedthrough the ASTM consensus process.2.Referenced Documents2.1 ASTM Standards:3D653 Terminology Relating to Soil,Rock,and ContainedFluidsD5549 Guide for The Contents of Geostatistical Site Inves-tigation Report(Withdrawn 2002)4D5922 Guide for Analysis of Spatial Variation in Geostatis-tical Site InvestigationsD5924 Guide for Selection of Simulation Approaches inGeostatistical Site Investigations1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.01 on Surface and SubsurfaceCharacterization.Current edition approved May 1,2010.Published September 2010.Originallyapproved in 1996.Last previous edition approved in 2004 as D5923 96(2004).DOI:10.1520/D5923-96R10.2The boldface numbers in parentheses refer to a list of references at the end ofthe text.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 additivity,na mathematical property of a regional-ized variable stating that it can be combined linearly in order todefine a similar variable on a larger support.3.1.2 block kriging,na form of kriging in which thevariable to be estimated has a rectangular or possibly irregularone-,two-,or three-dimensional support.3.1.3 drift,nin geostatistics,a systematic spatial variationof the local mean of a variable,usually expressed as apolynomial function of location coordinates.3.1.4 estimation,na procedure by which the value of avari