简介：Asimplemodelingapproachwassuggestedtosimulatepreferentialtransportofwaterandcontaminantsinsoil.AftersaturatedhydraulicconductivitywasinterpolatedbymeansofKrigeinterpolationmethodorscalingmethod,andthenzoned,thelocationswheresaturatedhydraulicconductivitywaslargerrepresentedregionswherepreferentialflowoccurred,becauseheterogeneityofsoil,oneofthemechanismsresultinginprefeentialflow,couldbereflectedthroughthedifferenceinsaturatedhydraulicconductivity,Themodelingapproachwasvalidatdthroughnumericalsimulationofcontaminanttansportinatwo-dimensionalhypotheticalsoilprofle.Theresultsofthenumericalsimulationshowedthattheapproachsuggestedinthisstudywasfeasible.

简介：Boththeoreticalandfieldobservationswereexaminedtostudythecloserelationshipbetweensoildegenerationandtheevolutionofgrasslandvegetation.Ageneraln-speciesmodelofequalcompetitionunderdifferentdegreesofsoildegradationwasappliedtofielddatainordertoprobethedynamicprocessesandmechanismsofvegetationevolutionduetotheeffectsofthesoil'secologicaldeteriorationongrasslandvegetation.Comparisonsweremadebetweenthetheoreticalresultsandthepracticalsurveyswithsatisfactoryresults.

简介：Coupledtransferofsoilwaterandheatinclosedcolumnsofhomogeneousredsoilwasstudiedunderlaboratoryconditions.Acoupledmodelwasconstructedusingsoilphysicaltheory,empiricalequationsandexperimentaldatatopredictthecoupledtransfer.Theresultsshowthattransportofsoilwaterwasaffectedbytemperaaturegradient,andthelargestnetwatertransportwasfoundinthesoilcolumnwithinitialwatercontentof0.148m^3m^-3,Atthesametime,temperaturechangeswiththetransportofsoilwaterwasinanonlinearshapeasheatparameterswrefunctionofwatercontent,andthechangesoftemperaturewerepositivelycorrelatedwiththenetamountofwatertransported.Numericalmodellingresultsshowthatthepredictedvaluesoftemperaturedistributionwereclosetotheobservedvalues,whilethepredictedvaluesofwatercontentexhibitedlimiteddeviationatbothendsofthesoilcolumnduetotheslighttemperaturechangesatbothends.ItWASindicatedthatthemodelproposedherewasapplicable.

简介：Researchsamplesweretakenfromanancientgravelstratumwhichisnotonlyarepresentativesoillayeralongthemiddle-lowerreachesoftheYangtzeRiverinEastChina,butalsooneoftheprimaryNeozoicstratainNanjingdistrict.Locatedmostlyonthesecondandthirdterraces,theancientgravelstrataformedthegeomorphiclandscapesofterraceandstep.Theywerecomplexinconstitution,variedwidelyinstability,ofmultiplesources,locallyderived,andassociatedwithbraidedstreamsinthedepositionenvironment.ACIPW(Cross,Iddings,PirssonandWashington)methodmodifiedbytheauthorwasusedtoanalyzethesoi-rock-formingmaterialsoffinergrains(lessthan2mminsize)oftheancientgravelstratum.Resultsoftheanalysisshowedthatthesandygrainswerecomposedofapatite,ilmenite,potassiumfeldspar,plagioclase,enstatiteandfreequartz,theclaymainlyofkaolinite,andthecementofacombinationofsilicon,aluminumandironataratioof46:44:10.Inthesoil-rock-formingprocesses,includingcompactionalsolidification,water-stableilluviation-cementation,homogeneousovergrowthandsoon,theloosesoil-rock-formingcomponentsgraduallychangedintoconsolidatedsoilandfurthertotheearlystageoflithification.Meanwhile,fromtheanalysis,wefoundthattheancientgravelstratumhadbeenprotectedbytheoverlyingXiashuloessorbasaltandtheoverloadingresultedinoverconsolidatedstrata.ThemodifiedCIPWmethodwasapplicableandeffectiveforsemi-quantitativeanalysis.