1.1本指南描述了可用于量化包气带内土壤水（或土壤水分）通量、土壤水运动速率和/或补给速率的技术。本指南并不打算涵盖所有可用方法。然而，所描述的技术确实代表了目前可用的最广泛使用的方法。 1.2本指南旨在详细说明可用于量化渗流区土壤水分通量的技术。在研究污染物移动和估计补充可再生地下水资源（即含水层）的水量时，通常需要这些数据。州和联邦监管指南通常要求在定义污染物旅行时间、性能评估和风险评估中提供这些信息。非饱和流和饱和流建模者在建立边界条件和校准其计算机模拟时都受益于这些数据。 1.3本指南是关于渗流区表征方法的一系列标准之一。已经制定了关于渗流区表征技术的其他标准。 1.4 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。文字 “ 标准 ” 在本文件标题中，仅表示该文件已通过ASTM共识程序获得批准。 1.5 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和健康实践，并确定监管要求的适用性。 ====意义和用途====== 土壤水分通量的测定是土壤物理和水文学学科的基本需求之一。需要定义地下水补给率，以进行供水预测、污染物迁移估计、性能/风险评估研究和渗透测试。本指南中概述的技术为各种目的和条件下量化土壤水分通量和/或补给率提供了许多替代方法。本指南并非旨在全面指导可用于量化土壤水分通量的技术，而是一个 “ 实践状况 ” 总结同样，本指南不打算用作这些方法性能的综合指南，这些详细方法可能会在稍后提供。 可能有助于实现这些方法的技术，例如采样网络设计，不属于本指南的一部分，但可能会在以后提供。 本指南中讨论的所有技术在量化土壤水分通量方面都有优点。影响方法选择的因素包括:需要/目标；费用测试的时间尺度；以及可防御性/再现性/减少不确定性。如果在给定场地或研究的决策过程中，对土壤水分通量信息的需求至关重要，建议应用多种技术。上述大多数技术都有与其使用/应用相关的独立假设。因此，在给定地点应用两种或多种技术可能有助于约束结果，或证实数据分布。这些分析中涉及的不确定性有时相当大，因此获取独立数据集的前景非常诱人。 如上所述，每种土壤水分通量量化技术都有相关的假设和局限性。提醒用户在给定站点应用这些技术时要注意这些限制/假设，以免违反任何条件，从而使数据无效。 一般来说，与基于土壤物理的建模方法相比，用于量化土壤水分通量的示踪技术具有更少的不确定性，因为它们基于传输现象的直接测量，而不是土壤特征数据/参数的间接测量。然而，预测未来土壤水分运动速率或瞬态行为的正向问题最好由建模应用程序解决。示踪方法可用于校准建模技术，或向建模技术提供边界条件数据。 文献中也提供了这些方法的公开评论 (1, 2, 3) .

1.1 This guide describes techniques that may be used to quantify the soil-water (or soil-moisture) flux, the soil-water movement rate, and/or the recharge rate within the vadose zone. This guide is not intended to be all-inclusive with regard to available methods. However, the techniques described do represent the most widely used methods currently available. 1.2 This guide was written to detail the techniques available for quantifying soil-moisture flux in the vadose zone. These data are commonly required in studies of contaminant movement and in estimating the amount of water replenishing a renewable groundwater resource, that is, an aquifer. State and federal regulatory guidelines typically require this information in defining contaminant travel times, in performance assessment, and in risk assessment. Both unsaturated and saturated flow modelers benefit from these data in establishing boundary conditions and for use in calibrations of their computer simulations. 1.3 This guide is one of a series of standards on vadose zone characterization methods. Other standards have been prepared on vadose zone characterization techniques. 1.4 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. 1.5 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 and health practices and determine the applicability of regulatory requirements prior to use. ====== Significance And Use ====== The determination of the soil-moisture flux is one of the fundamental needs in the soil physics and hydrology disciplines. The need arises from requirements for defining recharge rates to groundwater for water supply predictions, for contaminant transport estimates, for performance/risk assessment studies, and for infiltration testing purposes. The techniques outlined in this guide provide a number of alternatives for quantifying soil-moisture flux and/or the recharge rate for various purposes and conditions. This guide is not intended to be a comprehensive guide to techniques available for quantifying soil-moisture flux, but rather a “ state-of-the-practice ” summary. Likewise, this guide is not intended to be used as a comprehensive guide to performance of these methods, those detailed methods may come at a later time. Techniques that might be useful for the implementation of these methods, for example, sampling network design, are not part of this guide, but may come at a later time. All of the techniques discussed in this guide have merit when it comes to quantification of the soil-moisture flux. Factors influencing the choice of methods include: need/objectives; cost; time scale of test; and defensibility/reproducibility/reduction in uncertainty. If the need for soil-moisture flux information is crucial in the decision making process for a give site or study, the application of multiple techniques is recommended. Most of the techniques identified above have independent assumptions associated with their use/application. Therefore, the application of two or more techniques at a given site may help to bound the results, or corroborate data distributions. The uncertainties involved in these analyses are sometimes quite large, and therefore the prospect of acquiring independent data sets is quite attractive. As stated above, each of these techniques for quantification of soil-moisture flux has assumptions and limitations associated with it. The user is cautioned to be cognizant of those limitations/assumptions in applying these techniques at a given site so as not to violate any conditions and thereby invalidate the data. In general, the tracer techniques for quantifying soil-moisture flux will have less uncertainty associated with them than do the soil-physics based modeling approaches because they are based on direct measures of transport phenomena, rather than indirect measures of soil characteristic data/parameters. However, the forward problem of predicting future soil-water movement rates or transient behavior is best served by the modeling applications. The tracer methods may be used to calibrate, or supply boundary condition data to, the modeling techniques. Published reviews of these methods are also available in the literature (1, 2, 3) .