简介:Theestuaryandcoastisanareawherethelandandtheseainteractandaplaceinwhichhumanbeingsfrequentlymoveaboutsothatunderstandingandcontrollingthechangeanddevelopmentmodesofthecoastallandformplaysavitalpartinexploitingandprotectingcoastalresources.Amodelisthegeneralizationandabstractionofobjectivethings.Thispapersummarizesfourmethodsforthelandformdevelopmentofthetidalshoreandunderwaterdelta,mainlydiscussesthemodel'sstructuralelements,andpresentstheirspecificapplicationonthebasisoftheauthors'casestudy.Withtheapplicationoftheprofilemodel,thedynamicchangeofcoastallandformcanbeclearlyseenbycontrastingthedifferentprofilesofdifferentyears.Throughtheshrinking,expandingandtransformationoftheisobath,planemodelisusedtostudythemacro-changeoftheshoalandthecoastallandform.Speedmodelisanefficientmeanstoanalyzethetrendoferosionanddepositionandthelocalchangeinagreatareaofthesea.Statisticalsurveymodelisastaticanalysis,whichcanbeusedtoestablishtherelationshipbetweentheerosionanddepositionoftheshoalandthealtitudeandslopeofsurveyspot.
简介:Theobjectivesofthisstudyaretoassesslandsuitabilityandtopredictthespatialandtemporalchangesinlandusetypes(LUTs)byusingGIS-basedlandusemanagementdecisionsupportsystem.AGISdatabasewithdataonclimate,topography,soilcharacteristic,irrigationcondition,fertilizerapplication,andspecialsocioeconomicactivitieshasbeendevelopedandusedfortheevaluationoflandproductivityfordifferentcropsbyintegratingwithacropgrowthmodel--theerosionproductivityimpactcalculator(EPIC).Internationalfoodpolicysimulationmodel(IFPSIM)isalsoembeddedintoGISforthepredictionsofhowcropdemandsandcropmarketpriceswillchangeunderalternativepolicyscenarios.Aninferenceengine(IE)includinglandusechoicemodelisdevelopedtoillustratelandusechoicebehaviorbasedonlogitmodels,whichallowstoanalyzehowdiversifiedfactorsrangingfromclimatechanges,croppricechangestolandmanagementchangescanaffectthedistributionofagriculturallanduse.Atestforintegratedsimulationistakenineach0.1°by0.1°gridcelltopredictthechangeofagriculturallandusetypesatgloballevel.Globallandusechangesaresimulatedfrom1992to2050.