1.1 本指南涵盖特定场地或问题的地下水流动模型的应用和后续文档。在这种情况下，“地下水流模型”是指应用数学模型来解决特定场地的地下水流问题。 1.2 本指南说明了在开发地下水流动模型时应采取的主要步骤，该模型再现或模拟了已在现场研究的含水层系统。本指南不确定建模调查中使用的特定计算机代码、软件或算法。 1.3 本指南专门针对饱和、等温地下水流模型编写。 这些概念适用于设计用于模拟地下过程的各种模型，例如可变饱和流、裂隙介质中的流、密度相关流、溶质运移和多相运移现象；然而，本指南中没有描述这些其他过程的细节。 1.4 本指南并非包罗万象。每个地下水模型都是独特的，在其开发和应用中可能需要额外的程序。然而，所有此类附加分析应记录在模型报告中。 1.5 本指南是地下水模型应用的一系列标准之一。 其他标准包括 D5981 , D5490 , D5609 , D5610 , D5611 和 D6033 . 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 本指南提供了有组织的信息收集或一系列选项，并不推荐具体的行动方案。本文件不能取代教育或经验，应与专业判断一起使用。 并非本指南的所有方面都适用于所有情况。本ASTM标准不代表或取代必须根据其判断给定专业服务的充分性的谨慎标准，也不应在不考虑项目的许多独特方面的情况下应用本文件。本文件标题中的“标准”一词仅表示该文件已通过ASTM共识程序获得批准。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 模型应用程序 ( 1. ) , 4. 是以下方面的有用工具: 5.1.1 协助问题评估， 5.1.2 设计补救措施， 5.1.3 概念化和研究地下水流动过程， 5.1.4 为决策提供额外信息，以及 5.1.5 认识到数据的局限性，并指导新数据的收集。 5.2 地下水模型通常用于制定环境资源管理决策。支持这些决策的模型应具有科学合理性，并告知决策者模型预测中的不确定性程度。 这促使一些国家机构制定地下水建模标准 ( 2. ) . 本指南提供了开发、应用和记录地下水流模型的一致框架。 5.3 本指南介绍了应用地下水流动模型时理想遵循的步骤。地下水流动模型将基于可能使用数值、分析或其他适当技术的数学模型。 5.4 实践地下水建模师和希望在其指导下进行的建模工作中提供一致性的人员应使用本指南。 5.5 使用本指南开发和记录地下水流模型并不保证模型有效。本指南简单概述了建模过程中需要遵循的必要步骤。例如，如果裂隙和溶蚀通道中发生大量地下水流动，则在岩溶地形中开发等效多孔介质模型可能无效。在这种情况下，建模者可以遵循本指南中的步骤，而不是最终得到一个可防御的模型。

1.1 This guide covers the application and subsequent documentation of a groundwater flow model to a particular site or problem. In this context, “groundwater flow model” refers to the application of a mathematical model to the solution of a site-specific groundwater flow problem. 1.2 This guide illustrates the major steps to take in developing a groundwater flow model that reproduces or simulates an aquifer system that has been studied in the field. This guide does not identify particular computer codes, software, or algorithms used in the modeling investigation. 1.3 This guide is specifically written for saturated, isothermal, groundwater flow models. The concepts are applicable to a wide range of models designed to simulate subsurface processes, such as variably saturated flow, flow in fractured media, density-dependent flow, solute transport, and multiphase transport phenomena; however, the details of these other processes are not described in this guide. 1.4 This guide is not intended to be all inclusive. Each groundwater model is unique and may require additional procedures in its development and application. All such additional analyses should be documented, however, in the model report. 1.5 This guide is one of a series of standards on groundwater model applications. Other standards include D5981 , D5490 , D5609 , D5610 , D5611 , and D6033 . 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Model applications ( 1 ) , 4 are useful tools to: 5.1.1 Assist in problem evaluation, 5.1.2 Design remedial measures, 5.1.3 Conceptualize and study groundwater flow processes, 5.1.4 Provide additional information for decision making, and 5.1.5 Recognize limitations in data and guide collection of new data. 5.2 Groundwater models are routinely employed in making environmental resource management decisions. The model supporting these decisions should be scientifically defensible and decision-makers informed of the degree of uncertainty in the model predictions. This has prompted some state agencies to develop standards for groundwater modeling ( 2 ) . This guide provides a consistent framework within which to develop, apply, and document a groundwater flow model. 5.3 This guide presents steps ideally followed whenever a groundwater flow model is applied. The groundwater flow model will be based upon a mathematical model that may use numerical, analytical, or other appropriate technique. 5.4 This guide should be used by practicing groundwater modelers and by those wishing to provide consistency in modeling efforts performed under their direction. 5.5 Use of this guide to develop and document a groundwater flow model does not guarantee that the model is valid. This guide simply outlines the necessary steps to follow in the modeling process. For example, development of an equivalent porous media model in karst terrain may not be valid if significant groundwater flow takes place in fractures and solution channels. In this case, the modeler could follow the steps in this guide and not end up with a defensible model.