ASTM_D_6629_-_01_2012e1.pdf

Designation:D662901(Reapproved 2012)1Standard Guide forSelection of Methods for Estimating Soil Loss by Erosion1This standard is issued under the fixed designation D6629;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year 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.1NOTE6.1.1 was editorially revised in May 2012.1.Scope1.1 This guide describes methods used for estimating soillosses due to rill and interrill erosion.All known methods forwater erosion with a sediment yield component are listed.Thisguide provides complete reference citations for the variousmethods currently used to estimate soil loss by rill and interrillerosion.The referenced methods contain the rationale anddetailed procedures for determining rill and interrill soil loss.For each method listed,specific applicability,limitations,andlevel of complexity are briefly outlined in terms of the relativespatial scale,land use,hydrology,erosion,time scale,inputrequirements,and output.1.2 The referenced methods were developed for specificuses and may not be applicable in all cases.For example,someof the values derived by these methods estimate the amount ofsoil movement on a field without re-deposition while othersaccount for re-deposition and estimate off-field sediment yield.Most of these methods are not intended to predict sedimentyield.1.3 Metric(SI)Units.Some of the methods in this guide arewritten in the preferred English units.A discussion of theconversion of the final answer to metric units is included inparagraph 6.2.1.4 This guide offers an organized collection of informationor a series of options and does not recommend a specificcourse of action.This guide cannot replace education orexperience and should be used in conjunction with professionaljudgement.Not all aspects of this guide may be applicable inall circumstances.This guide is not intended to represent orreplace the standard of care by which the adequacy of a givenprofessional service must be judged,nor should this guide beapplied without consideration of a projects many uniqueaspects.The word“Standard”in the title of this guide has beenapproved through 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 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:2D653 Terminology Relating to Soil,Rock,and ContainedFluids3.Terminology3.1 While most of the terms used in this guide conform toTerminology D653,some are unique to this guide.These termsrelate to soil erosion and are used frequently in the methodsoutlined in this guide.NOTE1The Natural Resources Conservation Service was formerlythe Soil Conservation Service.3.2 Definitions:3.2.1 agronomythe science of field crop production andsoil management.3.2.2 denudationthe sum of the processes that result in thewearing away or the progressive lowering of the earths surfaceby weathering,mass wasting,or transportation;also thecombined destructive effects of such processes.3.2.3 erodibilitythe degree to which a soil is susceptible toerode.Some soils erode more readily than others due to the soilproperties.3.2.4 erosionthe wearing away of soil and rock byweathering,mass wasting,and the action of streams,glaciers,waves,wind,and underground water.3.2.5 fallowallowing cropland to lie idle,either tilled oruntilled,during the whole or greater portion of the growingseason.3.2.6 fertility(soil)the quality of a soil that enables it toprovide nutrients in adequate amounts and in proper balance1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.22 on Soil as a Medium forPlant Growth.Current edition approved May 15,2012.Published December 2012.Originallyapproved in 2001.Last previous edition approved in 2007 as D6629 01(2007).DOI:10.1520/D6629-01R12E1.2For 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 website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 for the growth of specified plants when other growth factors,such as light,moisture,temperature,and the physical conditionof the soil are favorable.3.2.7 mulcha natural or artificial layer of suitable materi-als that aid in soil stabilization and soil moisture conservation,thus providing micro-climatic conditions suitable for germina-tion and growth.3.2.8 pasturean area devoted to the production of forage,introduced or native,and harvested by grazing.3.2.9 rilla sma