简介：Wetlandsoilqualitydegradationcausedbylarge-scaleagriculturalreclamationontheSanjiangPlainofNortheastChinahasbeenwidelyreported.Arelativesoilqualityevaluation(RSQE)modelandaprojectionpursuitevaluation(PPE)modelbasedonreal-codedacceleratinggeneticalgorithmwereintroducedtoevaluatequalityvariationsintoplayersofthemainwetlandsoilsontheSanjiangPlainin1999and2003,respectively.Assoilqualitydegradationboundarieswerevague,thisstudyestablishedtwofuzzysyntheticevaluation(FSE)modelsbasedontheoriginaldataandcriteriausedintheRSQEandPPEmodels.TheoutputsofthetwoFSEmodelswereobtainedbychoosingtwofuzzycompositeoperatorsM(∧,∨)andM(·,⊕).StatisticalanalysisshowedthattheresultsoftheFSE,RSQE,andPPEmodelswerecorrelated.Inparticular,outputsoftheFSEmodelusingM(·,⊕)weresignificantlycorrelatedwiththoseoftheRSQEmodelwithr=0.989atP<0.01.ComparedwithRSQEandPPEmodels,theFSEmodelmaybemoreobjectiveinshowingsoilqualityvariationsandwasclosertothenaturalsituation,showingthefeasibilityandapplicabilityoftheFSEmodelinevaluatingsoilqualitydegradation.However,thechoiceofcompositeoperatorwasofcriticalimportance.ThestudyofwetlandsoilqualitydegradationontheSanjiangPlainwasofscientificandpracticalsignificanceforprotectionandmanagementofsoilsandforsustainabledevelopmentofagricultureinthisareainthefuture.

简介：Soilsalinityandhydrologicdatasetswereassembledtoanalyzethespatio-temporalvariabilityofsalinizationinFengqiuCounty,HenanProvince,China,inthealluvialplainofthelowerreachesoftheYellowRiver.Thesalinesoilandgroundwaterdepthdataofthecountyin1981wereobtainedtoserveasahistoricalreference.Electricalconductivity(EC)of293surfacesoilsamplestakenfrom2km×2kmgridsin2007and40soilprofilesacquiredin2008wasanalyzedandusedforcomparativemapping.OrdinarykrigingwasappliedtopredictECatunobservedlocationstoderivethehorizontalandverticaldistributionpatternsandvariationofsoilsalinity.Groundwatertabledatafrom22observationwellsin2008werecollectedandusedasinputforregressionkrigingtopredictthemaximumgroundwaterdepthofthecountyin2008.ChangesinthegroundwaterlevelofFengqiuCountyin27yearsfrom1981to2008wascalculated.Twoquantitativecriteria,themeanerrororbias(ME)andthemeansquarederror(MSE),werecomputedtoassesstheestimationaccuracyofthekrigingpredictions.Theresultsdemonstratedthatthesoilsalinityintheuppersoillayersdecreaseddramaticallyandthetaxonomicallydefinedsalinesoilswerepresentonlyinafewmicro-landscapesafter27years.Presently,thesoilswithrelativelyelevatedsaltcontentweremainlydistributedindepressionsalongtheYellowRiverbed.Thereductioninsurfacesoilsalinitycorrespondedtothelocationswithdeepenedmaximumgroundwaterdepth.Itcouldbeconcludedthatgroundwatertablerecessionallowedwatertomovedeeperintothesoilprofile,transportingsaltswithit,andthusplayedanimportantroleinreducingsoilsalinityinthisregion.Accumulationofsaltsinthesoilprofilesatvariousdepthsbelowthesurfaceindicatedthatsecondarysoilsalinizationwouldoccurwhenthegroundwaterwasnotcontrolledatasafedepth.

简介：PhysiographyandsoilinMaeRimwatershed,ChiangMaiProvince,Thailandwereinvestigatedbyusingaerialphotographsandsatelliteimageinconjunctionwithfieldwork,andsoilinfiltrationrateandsoilshearresistanceweremeasuredinfield.ManyfactorsaffectingrunoffwereanalyzedusigtheIntegratedLandandWaterInformaitonSystem(ILWIS).Asaresult,amodeldeterminingfloodhazarwassetup.Threempsincludingrunoffcurvenumbermap,runoffcoefficentmap,andfloodinumdationmapwerecreated,Inaddition,thetimeofconcentrationwaspredicted.