ASTM_D_5922_-_96_2010.pdf

Designation:D592296(Reapproved 2010)Standard Guide forAnalysis of Spatial Variation in Geostatistical SiteInvestigations1This standard is issued under the fixed designation D5922;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.This guide is concerned with theanalysis,interpretation,and modeling of spatial variation.The purpose of this guide is to offerguidance based on a consensus of views but not to establish a standard practice to follow in all cases.1.Scope1.1 This guide covers recommendations for analyzing,in-terpreting,and modeling spatial variation of regionalizedvariables in geotechnical and environmental site investigations.1.2 The measures of spatial variation discussed in this guideinclude variograms and correlograms;these are fully describedin Refs.(1-4).21.3 This guide is intended to assist those who are alreadyfamiliar with the geostatistical tools discussed herein and doesnot provide introductory information on the analysis,interpre-tation,and modeling of spatial variation.1.4 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.1.5 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)4D5923 Guide for Selection of Kriging Methods in Geostatis-tical Site InvestigationsD5924 Guide for Selection of Simulation Approaches inGeostatistical Site Investigations3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 anisotropy,nin geostatistics,a property of the var-iogram or covariance stating that different spatial variationstructures are observed in different directions.3.1.2 correlogram,na measure of spatial variation ex-pressing the coefficient of correlation between two variables asa function of the lag separating their locations.1This 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 D592296(2004).DOI:10.1520/D5922-96R10.2The 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 3.1.3 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 avariable at an unsampled location is predicted using a weightedaverage of sample values from the neighborhood of thatlocation.3.1.5 experimental variogram,nan experimental measureof spatial variation usually calculated as one half the averagesquared difference between all pairs of data values within thesame lag.3.1.6 geometric anisotropy,na form of anisotropy inwhich the variogram range changes with direction while the sillremains constant.3.1.7 lag,nin geostatistics,the vector separating t