1、Designation: D 6033 96 (Reapproved 2002)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 (e) 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 gro
3、und-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 tho
4、r-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 c
5、omponents 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 condition
6、s. 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 compo
7、nents 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 descr
9、iptions 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. I
10、nthose 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
11、to 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 org
12、anized 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 st
13、andard 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 do
14、cument has been approvedthrough the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:D 653 Terminology Relating to Soil, Rock, and ContainedFluids2D 5447 Guide for Application of a Ground-Water FlowModel to a Site-Specific Problem2D 5490 Guide for Comparing Ground-Water Flow ModelSim
15、ulations to Site-Specific Information2D 5609 Guide for Defining Boundary Conditions inGround-Water Flow Modeling2D 5610 Guide for Defining Initial Conditions in Ground-Water Flow Modeling2D 5611 Guide for Conducting a Sensitivity Analysis for aGround-Water Flow Model Application2D 5718 Guide for Doc
16、umenting a Ground-Water FlowModel Application21This guide is under the jurisdiction of ASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.21 on Ground Water andVadose Zone Investigations.Current edition approved Oct. 10, 1996. Published May 1997.2Annual Book of A
17、STM Standards, Vol 04.08.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Terminology3.1 DefinitionsFor definitions of terms used in this guide,see Terminology D 653.3.2 Definitions of Terms Specific to This Standard:3.2.1 analytic
18、al model, na model 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 arekn
19、own and the system 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 reg
20、ular-spaced mesh 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 solv
21、ingtechniques.3.2.4 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 betwe
22、en thesepoints is 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
23、 offers the user 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 modeli
24、ng code, nthe nonparameter-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
25、application of a 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
26、responses.3.2.9.1 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 parameteridentifi
27、cation model. Typically, 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 cons
28、idered inverse models.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 kno
29、wn. Thesemodels are 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
30、 has become an important 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
31、their quality, espe-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, an
32、d engineering designsaffecting 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
33、 that project, or 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 a
34、ctual running the code for situationsrelevant to the project for which a code is to be selected due toincompleteness, poor organization, or incorrectness of a codesdocumentation.44.4 Systematic and comprehensive description of a codesfeatures based on an informative classification provides thenecess
35、ary basis for efficient selection of a ground-water mod-eling code for a 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 existing
36、3National Research Council (NRC), Committee on Ground-Water ModelingAssessment, Water Science and Technology Board, “Ground-water Models: 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:Sy
37、stematic Evaluation and Testing of Code Functionality, Performance, andApplicability to Practical Problems,” EPA/600/R-97/007, R.S. Kerr EnvironmentalResearch Laboratory, U.S. Environmental Protection Agency, Ada, Oklahoma,1996.D 6033 96 (2002)2ground-water modeling code through the formulation of a
38、 codeclassification 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 inform
39、a-tion of such software 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 condit
40、ions and distributors; 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, includ
41、ing theresults of 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 classif
42、ication is used based 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
43、The mathematical 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 out
44、put.5.3.2 Management 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. Ing
45、eneral, however, 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 be
46、one or more of the 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 to
47、ol for engineering 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
48、classification based 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
49、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, velocity(vector), fluid flux (vector), stream- or pathlines, isochrones,contaminant fronts, contaminant concentration (in both liquidand solid phase), solute flux (vector), temperature, enthalpy,heat flux (vector), location of (saltwater/freshwater) interface,water balance, and chemical mass
