1、Designation:D 6642 01Standard Guide forComparison of Techniques to Quantify the Soil-Water(Moisture)Flux1This standard is issued under the fixed designation D 6642;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revi
2、sion.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 describes techniques that may be used toquantify the soil-water(or soil-moisture)flux,the soil-watermovement rate,and/or
3、 the recharge rate within the vadosezone.This guide is not intended to be all-inclusive with regardto available methods.However,the techniques described dorepresent the most widely used methods currently available.1.2 This guide was written to detail the techniques availablefor quantifying soil-mois
4、ture flux in the vadose zone.Thesedata are commonly required in studies of contaminant move-ment and in estimating the amount of water replenishing arenewable ground-water resource,that is,an aquifer.State andfederal regulatory guidelines typically require this informationin defining contaminant tra
5、vel times,in performance assess-ment,and in risk assessment.Both unsaturated and saturatedflow modelers benefit from these data in establishing boundaryconditions and for use in calibrations of their computersimulations.1.3 This standard is one of a series of standards on vadosezone characterization
6、 methods.Other standards have beenprepared on vadose zone characterization techniques.1.4 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 conjunc
7、tion 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 considera
8、tion 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.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the
9、user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2.Referenced Documents2.1 ASTM Standards:D 653 Standard Terminology Relating to Soil,Rock,andContained Fluids2D 1452 Practice for Soil Investigations a
10、nd Sampling byAuger Boring2D 2216 Test Method for Laboratory Determination of Water(Moisture)Content of Soil and Rock by Mass2D 3404 Guide to Measuring Matric Potential in the VadoseZone Using Tensiometers2D 4643 Test Method for Determination of Water(Moisture)Content of Soil by the Microwave Oven H
11、eating2D 4696 Guide for Pore-Liquid Sampling from the VadoseZone2D 4700 Guide for Soil Sampling from the Vadose Zone2D 4944 Test Method for Field Determination of Water(Moisture)Content of Soil by the Calcium Carbide GasPressure Tester Method2D 5126 Guide for Comparison of Field Methods for Deter-mi
12、ning Hydraulic Conductivity in the Vadose Zone2D 5220 Test Method for Water Content of Soil and RockIn-Place by the Neutron Depth Probe Method23.Terminology3.1 Definitions:3.1.1 chlorine-36,36Cla radioactive isotope of chlorine,containing one extra neutron in the nucleus,and a decayhalf-life of 300,
13、000 years.3.1.2 deuterium,2Ha stable isotope of hydrogen,contain-ing one extra neutron in the nucleus.3.1.3 oxygen-18,18Oa stable isotope of oxygen,contain-ing two extra neutrons in the nucleus.3.1.4 recharge flux,(LT1)the soil-moisture flux of watermoving through the vadose zone,beneath the zone of
14、 evapo-transpirative uptake,which eventually replenishes water to anunderlying aquifer.3.1.5 soil-moisture flux,(LT1)synonymous with specificdischarge.3.1.6 specific discharge,(LT1)the rate of flow of waterthrough a porous medium per unit area measured at a rightangle to the direction of flow.(D 653
15、)1This 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 March 10,2001.Published May 2001.2Annual Book of ASTM Standards,Vol 04.08.1Copyright ASTM Interna
16、tional,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.3.1.7 specific flux,(LT1)synonymous with specific dis-charge.3.1.8 tritium,3Ha radioactive isotope of hydrogen,con-taining two extra neutrons in the nucleus,and a decay half-lifeof 12.3 years.3.2 Definitions of other terminology used in this guide maybe found in Standard D 653.4.Summary of the Guide4.1 The quantitative techniques described for assessingsoil-moisture flux are:4.2 Water Balance MethodsThe water
