1、Designation: D 6033 96 (Reapproved 2008)Standard Guide forDescribing the Functionality of a Ground-Water ModelingCode1This standard is issued under the fixed designation D 6033; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear 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 presents a systematic approach to the classi-fication and description of computer codes used in grou
3、nd-water modeling. Due to the complex nature of fluid flow andbiotic and chemical transport in the subsurface, many differenttypes of ground-water modeling codes exist, each havingspecific capabilities and limitations. Determining the mostappropriate code for a particular application requires a thor
4、-ough analysis of the problem at hand and the required andavailable resources, as well as a detailed description of thefunctionality of potentially applicable codes.1.2 Typically, ground-water modeling codes are nonparam-eterized mathematical descriptions of the causal relationshipsamong selected co
5、mponents of the aqueous subsurface and thechemical and biological processes taking place in these sys-tems. Many of these codes focus on the presence and move-ment of water, dissolved chemical species and biota, eitherunder fully or partially saturated conditions, or a combinationof these conditions
6、. Other codes handle the joint movement ofwater and other fluids, either as a gas or a nonaqueous phaseliquid, or both, and the complex phase transfers that might takeplace between them. Some codes handle interactions betweenthe aqueous subsurface (for example, a ground-water system)and other compon
7、ents of the hydrologic system or withnonaqueous components of the environment.1.3 The classification protocol is based on an analysis of themajor function groups present in ground-water modelingcodes.Additional code functions and features may be identifiedin determining the functionality of a code.
8、A complete descrip-tion of a codes functionality contains the details necessary tounderstand the capabilities and potential use of a ground-watermodeling code. Tables are provided with explanations andexamples of functions and function groups for selected types ofcodes. Consistent use of the descrip
9、tions provided in theclassification protocol and elaborate functionality analysisform the basis for efficient code selection.1.4 Although ground-water modeling codes exist for simu-lation of many different ground-water systems, one mayencounter situations in which no existing code is applicable. Int
10、hose cases, the systematic description of modeling needs maybe based on the methodology presented in this guide.1.5 This guide is one of a series of guides on ground-watermodeling codes and their applications, such as Guides D 5447,D 5490, D 5609, D 5610, D 5611, and D 5718.1.6 Complete adherence to
11、 this guide may not be feasible.For example, research developments may result in new typesof codes not yet described in this guide. In any case, codedocumentation should contain a section containing a completedescription of a codes functions, features, and capabilities.1.7 This guide offers an organ
12、ized 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 stan
13、dard 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 docu
14、ment has been approvedthrough the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:2D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 5447 Guide for Application of a Ground-Water FlowModel to a Site-Specific ProblemD 5490 Guide for Comparing Ground-Water Flow ModelSimula
15、tions to Site-Specific Information1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.21 on Ground Water andVadose Zone Investigations.Current edition approved Sept. 15, 2008. Published November 2008. Originallyapproved in 1
16、996. Last previous edition approved in 2002 as D 6033 96 (2002)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 websit
17、e.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D 5609 Guide for Defining Boundary Conditions inGround-Water Flow ModelingD 5610 Guide for Defining Initial Conditions in Ground-Water Flow ModelingD 5611 Guide for Conducting a Sensi
18、tivity Analysis for aGround-Water Flow Model ApplicationD 5718 Guide for Documenting a Ground-Water FlowModel Application3. Terminology3.1 Definitions: For definitions of terms used in this guide,see Terminology D 653.3.2 Definitions of Terms Specific to This Standard:3.2.1 analytical model, na mode
19、l that uses closed formsolutions to the governing equations applicable to ground-water flow and transport processes.3.2.2 backtracking model, nan application of a math-ematical model for determining ground-water system stressesand boundary conditions when the system parameters areknown and the syste
20、m responses are either known or bounded.3.2.3 finite difference model, na type of approximate,numerical model that uses a discrete technique for solving thegoverning partial differential equation (PDE) consisting ofreplacing the continuous domain of interest by a finite numberof regular-spaced mesh
21、or grid points (that is, nodes) repre-senting volume-averaged subdomain properties, approximatingthe derivatives of the PDE for each of these points using finitedifferences, and solving the resulting set of linear or nonlinearalgebraic equations using direct or iterative matrix solvingtechniques.3.2
22、.4 finite element model, na type of approximate, nu-merical model that uses a discrete technique for solving thegoverning partial differential equation (PDE) wherein thedomain of interest is represented by a finite number of mesh orgrid points (that is, nodes), and information between thesepoints is
23、 obtained by interpolation using piecewise continuouspolynomials. The resulting set of linear or nonlinear algebraicequations is solved using direct or iterative matrix solvingtechniques.3.2.5 functionality, nof a ground-water modeling code,the set of functions and features the code offers the user
24、interms of model framework geometry, simulated processes,boundary conditions, and analytical and operational capabili-ties.3.2.6 ground-water flow model, nan application of amathematical model to represent a regional or site-specificground-water flow system.3.2.7 ground-water modeling code, nthe non
25、parameter-ized computer code used in ground-water modeling to repre-sent a nonunique, simplified mathematical description of thephysical framework, geometry, active processes, and boundaryconditions present in a reference subsurface hydrologic system.3.2.8 heat transport model, nan application of a
26、math-ematical model to represent the movement of heat or energy ina ground-water system.3.2.9 inverse model, nan application of a mathematicalmodel designed for evaluating ground-water system param-eters and stresses by minimizing the differences betweencomputed and observed system responses.3.2.9.1
27、 DiscussionThe term inverse model refers in gen-eral to a numerical code that incorporates a systematic,automated procedure to minimize the differences betweenobserved and computed system responses. This type of modelalso is known as a parameter estimation model or parameteridentification model. Typ
28、ically, these models are based onnumerical simulation of the ground-water system. Aquifer testand tracer test analysis software are often based on analyticalmodels of the ground-water system. Since they include auto-mated procedures to estimate the system parameters, they canbe considered inverse mo
29、dels.3.2.10 numerical model, na model that uses numericalmethods to solve the governing equations of the applicableproblem.3.2.11 prediction model, nan application of a mathemati-cal model designed for predicting ground-water system re-sponses, assuming the system parameters are known. Thesemodels a
30、re based on a so-called forward or direct mathematicalformulation of the physical processes.3.2.12 solute transport model, nan application of a math-ematical model to represent the movement of chemical speciesdissolved in ground water.4. Significance and Use4.1 Ground-water modeling has become an im
31、portant meth-odology in support of the planning and decision-makingprocesses involved in ground-water management. Ground-water models provide an analytical framework for obtaining anunderstanding of the mechanisms and controls of ground-watersystems and the processes that influence their quality, es
32、pe-cially those caused by human intervention in such systems.Increasingly, models are an integral part of water resourcesassessment, protection and restoration studies, and provideessential and cost-effective support for planning and screeningof alternative policies, regulations, and engineering des
33、ignsaffecting ground water.34.2 There are many different ground-water modeling codesavailable, each with their own capabilities, operational charac-teristics, and limitations. If modeling is considered for aproject, it is important to determine if a particular code isappropriate for that project, or
34、 if a code exists that can performthe simulations required in the project.4.3 In practice, it is often difficult to determine the capabili-ties, operational characteristics, and limitations of a particularground-water modeling code from the documentation, or evenimpossible without actual running the
35、 code for situationsrelevant to the project for which a code is to be selected due toincompleteness, poor organization, or incorrectness of a codesdocumentation.43National Research Council (NRC), Committee on Ground-Water ModelingAssessment, Water Science and Technology Board, “Ground-water Models:
36、Scien-tific and Regulatory Applications,” National Academy Press, Washington, DC,1990.4van der Heijde, P. K. M., and Kanzer, D. A., “Ground-water Model Testing:Systematic Evaluation and Testing of Code Functionality, Performance, andApplicability to Practical Problems,” EPA/600/R-97/007, R.S. Kerr E
37、nvironmentalResearch Laboratory, U.S. Environmental Protection Agency, Ada, Oklahoma,1996.D 6033 96 (2008)24.4 Systematic and comprehensive description of a codesfeatures based on an informative classification provides thenecessary basis for efficient selection of a ground-water mod-eling code for a
38、 particular project or for the determination thatno such code exists. This guide is intended to encouragecorrectness, consistency, and completeness in the descriptionof the functions, capabilities, and limitations of an existingground-water modeling code through the formulation of a codeclassificati
39、on system and the presentation of code descriptionguidelines.5. Classification of Ground-Water Modeling Codes5.1 There are many ground-water modeling codes availabledesigned to simulate, describe, or analyze different types ofground-water systems and problems. The descriptive informa-tion of such so
40、ftware can be divided in three groups.55.1.1 General Software Information, includes such items ascode name, version number, and release date of currentversion; development team; supported computer platform(s)and requirements; software language(s) and requirements;availability conditions and distribu
41、tors; and software supportand maintenance;5.1.2 Simulation System Information, refers to descriptionsof the nature of the systems that can be simulated, the methodof simulation, the computed variables, and the required modelinput; and,5.1.3 Performance Evaluation Information, including theresults of
42、 code verification, analysis of the sensitivity of thedependent variable for natural variations in system controls andsystem parameters (that is, system input), and listing ofoperational limitations.5.2 To describe systematically the features of ground-watermodeling codes, a classification is used b
43、ased on simulationsystem information (see Table 1). Three primary categories ofcode features can be distinguished as follows:55.2.1 The (design) purpose(s) or objective(s) of the soft-ware;5.2.2 The nature of the ground-water system that can besimulated with the software; and,5.2.3 The mathematical
44、framework.5.3 Objective-Oriented Classification5(see Table 1):5.3.1 The purpose or objective of a ground-water modelingcode can be defined in terms of the applicability of the code tocertain types of ground-water management problems, thecodes functional use, or its computational output.5.3.2 Managem
45、ent objectives may include requirements,such as type of problems which may be simulated, type ofcalculations and level of resolution required, acceptable accu-racy, representation of specific management strategies, andother technical, scientific, social, and economic objectives. Ingeneral, however,
46、it is not practical to develop a standardclassification and description system based on such manage-ment objectives, as these are taken more easily into account inthe code selection process than in the code documentationphase.5.3.3 By design, a codes functional-use objectives may beone or more of th
47、e following:5.3.3.1 To enable evaluation of a new theory and relatedhypotheses as part of research;5.3.3.2 To be used as a tool in education and demonstrationof principles;5.3.3.3 To be used as a generic tool for ground-water systemcharacterization;5.3.3.4 To be used as a generic tool for engineerin
48、g design(for example, well fields, excavations, remedial actions, and soforth);5.3.3.5 To be used as a site- or problem-dedicated tool(including site- or problem-specific data); and,5.3.3.6 To be used as a generic or dedicated tool for policyor management strategy screening.5.3.4 A classification ba
49、sed on computational output in-cludes the following categories:5.3.4.1 Screening or Ranking ModelsFacilitating qualita-tive evaluation of relative merits and disadvantages of variousmanagement or engineering alternatives;5.3.4.2 Prediction ModelsPredicting system responses,assuming the system parameters (for example, hydraulic con-ductivity, storativity) and system stresses (for example, bound-ary conditions) are known (that is, independent field informa-tion); the most common variables computed by predictionmodels are hydraulic head, drawdown, pressure, veloci
