The spatial—temporal dynamic characteristics of the marsh in the Sanjianlg Plain

(整期优先)网络出版时间:2003-02-12
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UsingthemethodsofcombininglandscapeecologywithGISspatialanalysis,thispaperanalysesthedynamicsofthemarshlandscapestuctureoftheSanjingPlaininthepast20years,furthermore,takingFujinCounty,locatedinthenorthoftheplain,asanexample,analyzestheconversionbetweenmarshandotherlandusetypes.ItisshownthatthemarshintheSanjiangPlaindecreasedgreatlyinthepast20years,butthetrendhasbeguntoreverse,Themarshareadecreasedby51.33%from1980to1996,whereasitdecreasedby4.19%from1996to2000.Thefragmentationofthemarshincreased;thenumberofthepatchesincreasedby326from1986to1996,whereasitonlyincreasedby18patchesfrom1996to2000,Itisobviousthatthespeedofpatchesnumberdiminishedandthemarshfragmentationdecreased,whichshowsthatthereclamationofthemarshconvertedfromthefragmentationtothebriminalargeareaofthemarsh.Thereclaimedmarshhasmainlyconvertedtopaddyfieldanddryland.Largeareaofthemarsh.Thereclaimedmarshhasmainlyconvertedtopaddyfiedldanddryland.Large-scalereclamationintheSanjiangPlaininfluencesitsnaturalenvironmentdirectly:theclimateoftheregionturnsfromcoldandwettowarmanddry,whichmakesthemarshbothinthelow-temperaturenorthernpartandinthedeeplystagnanteasternpartsuitableforfurtheragriculturaldevelopment.