ASTM_D_5880_-_95_2006.pdf

Designation:D588095(Reapproved 2006)Standard Guide forSubsurface Flow and Transport Modeling1This standard is issued under the fixed designation D5880;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.1.Scope1.1 This guide covers an overview of subsurface fluid-flow(groundwater)modeling.The term subsurface fluid flow isused to reduce misunderstanding regarding groundwater,soilwater,vapors including air in subsurface pores,and non-aqueous phase liquids.Increased understanding of fluid-flowphenomena is the combined result of field investigations andtheoretical development of mathematical methods to describethe observations.The results are methods for modeling viscousfluids and air flow,in addition to water,that are practical andappropriate.1.2 This guide includes many terms to assist the user inunderstanding the information presented here.A groundwatersystem(soils and water)may be represented by a physical,electrical,or mathematical model,as described in 6.4.3.Thisguide focuses on mathematical models.The term mathematicalmodel is defined in 3.1.11;however,it will be most often usedto refer to the subset of models requiring a computer.1.3 This guide introduces topics for which other standardshave been developed.The process of applying a groundwaterflow model is described in Guide D5447.The process includesdefining boundary conditions(Guide D5609),initial conditions(Guide D5610),performing a sensitivity analysis(GuideD5611),and documenting a flow model application(GuideD5718).Other steps include developing a conceptual modeland calibrating the model.As part of calibration,simulationsare compared to site-specific information(Guide D5490),suchas water levels.1.4 Model use and misuse,limitations,and sources of errorin modeling are discussed in this standard.This guide does notendorse particular computer software or algorithms used in themodeling investigation.However,this guide does providereferences to some particular codes that are representative ofdifferent types of models.1.5 Typically,a computer model consists of two parts;computer code that is sometimes called the computer programor software,and a data set that constitutes the input parametersthat make up the boundary and initial conditions,and mediumand fluid properties.A standard has been developed to addressevaluation of model codes(see Practice E978).1.6 Standards have been prepared to describe specific as-pects of modeling,such as simulating subsurface air flow usinggroundwater flow modeling codes(see Guide D5719)andmodeling as part of the risk-based corrective action processapplied at petroleum release sites(see Practice E1739).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:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD4105 Test Method for(Analytical Procedure)for Deter-mining Transmissivity and Storage Coefficient of Non-leaky Confined Aquifers by the Modified Theis Nonequi-librium MethodD5447 Guide for Application of a Ground-Water FlowModel to a Site-Specific ProblemD5490 Guide for Comparing Ground-Water Flow ModelSimulations to Site-Specific InformationD5609 Guide for Defining Boundary Conditions in Ground-Water Flow ModelingD5610 Guide for Defining Initial Conditions in Ground-Water Flow Modeling1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.21 on Groundwater andVadose Zone Investigations.Current edition approved July 1,2006.Published July 2006.Originally approvedin 1995.Last previous edition approved in 2000 as D5880 95(2000).DOI:10.1520/D5880-95R06.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesNOTICE:This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International(www.astm.org)for the latest information1D5611 Guide fo