Acomparativeanalysisonspatialpatternsandprocesseso

1878-0296©2010PublishedbyElsevierdoi:10.1016/j.proenv.2010.10.037Availableonlineat(2010)315–332InternationalSocietyforEnvironmentalInformationSciences2010AnnualConference(ISEIS)Acomparativeanalysisonspatialpatternsandprocessesofthreetypicalwetlandecosystemsin3Harea,ChinaAinongLia*,WeiDenga,BoKonga,MengqiangSonga,WenlanFengb,XiaoningLub,GuangbinLeia,JunhongBaicaInstituteofMountainHazardsandEnvironment,CAS,Chengdu610041,ChinabDepartmentofEnvironmentalEngineering,CUIT,Chengdu610225,ChinacCollegeofResourcesScienceandTechnology,BeijingNormalUniversity,Beijing,100875,ChinaAbstractThecomparativestudyonthedifferentcomponentsinspatialpatternisofparamountimportancetotherevealingoftheinteractionandfeedbackmechanismamongthedifferentcomponents,anditisveryusefulforustounderstandtheoverallcorrelationbetweenstructure-functionandpattern-processofthewetlandsystem.ByselectingthewetlandsystemintheestuaryofYellowRiverDelta,Huaihe-Hongzeriver-lakeandBaiyangdianlake-marshastypicalregions,thisstudyanalyzecomparativelyonthesimilarities,thedifferencesandtheinternalconnectionsofthethreemajortypicalwetlandsystemsin3HAreainviewofthecharacteristicsofthewetlandlandscapespatialpatternandtheirchanges.Thestudyutilizestotallysixperiodsofremotesensingimages(during1970s-2000s)tointerpretthechronologicalspatialdataofthewetlandsystemlandscapeovertherecent30years,andalsoapplytheapproachofclassiclandscapeecologymethodtoanalyzethespatialpatternstatusandthescenarioplaybackofthewetlandsystemineachtypicalregion.Theresultsdiscoverthatallthetypicalwetlandsystemsin3HAreapresentatrendofdegradationanddifferentdrivingmechanisms,andreflectthecomplexpatternofwetlandsystemsinthe3HArea.©2010PublishedbyElsevierLtd.Keywords:3HArea;wetlandspatialpattern;scenarioplayback;comparativeanalysis;remotesensing1.IntroductionWetlandsareaspecialkindofecosystems.InaccordancewiththedefinitionofConventiononWetlands[1],marshes,peatlands,fens,lakes,rivers,floodplains,deltas,valleyflats,reservoirs,ponds,paddylandsandtheseaareawithatidewaterdepthbelow6meters,allbelongtothecategoryofwetlands.Wetlandsareknownas“kidneyoftheearth”,functioningecologically,environmentallyandproductivelyintheaspectsoffloodstorage,climateregulation,pollutioncontrol,soilerosionreduction,landscaping,andmaintenanceofbiologicaldiversityand*Correspondingauthor.Tel.:[phone];fax:[phone]E-mailaddress:[e-mail].316AinongLietal./ProcediaEnvironmentalSciences2(2010)315–332productivity.Somestudieshaveshownthatvarioustypesofecosystemsworldwideeachyearprovidetheserviceworthyofatleast33trillion,including4.9trillionU.S.dollarsfromthewetlands[2].AccordingtoU.S.scientists[3-4],eachhectareofwetlandeachyearcanproducethevalueof4thousandto14thousandU.S.dollarsormore,2-7timesmorethantropicalrainforestsand45-160timesmorethanfarmlandecosystems.However,inrecentyears,wetlandcultivation,pollutionandoverexploitationofresourcescausewetlandstobecomeoneofthemostthreatenedglobalecosystems.Since1900,globalwetlandareahascutdown50%,currentlywithonly573millionhm2,accountingfor6%ofEarth'slandarea[5].Theconservationandwiseuseofwetlandshasarousedinternationalconcernofthewetlandstudygroups,whichbecomesoneofthehotissuesforglobalecosystemstudies.Inrecentyears,duetotherapidpopulationgrowthandeconomicdevelopmentinchina,Wetlandhasreducedrapidly.TheNationalnaturalorsemi-naturalwetlandsonlyaccountfor3.77%oflandarea[6],farlessthan6%oftheworldaveragelevel.Wetlandareasareencounteredwiththeproblemsofareashrinking,waterpollution,ecologicalimbalance,functionaldecline,etc.,whichdirectlyendangerthesustainabledevelopmentofsocialeconomy,especiallyinHuang-Huai-Hai(3H)area.Thewetlandsin3Hareatakeontheuniquespatialpatternof“threelongitudinalandtwolatitudinal”watersystem,withtheeasternandthemiddleroutesofSouth-to-NorthWaterDiversionProjectrunningcrosstheHuaiheRiver,YellowRiverandHaiheRiver,formingthewetlandsystemcomposedofdifferentcomponentslikerivers,lakes,marshes,estuaries,etc.,andfurtherbecomethevitalcentertomaintainthelifeoftheregionalecologicalenvironment[6].Throughthehydro-driveofthecenter,thenetworkofdiversewetlandsisestablished,maintainingandprotectingthenaturaleco-systemsandprocesses,andsupportingthesustainabledevelopmentofregionaleconomy.Butnow,the3Hareasareundertheimpactandthreatofintensifiedhumanactivities,especiallytheagriculturedevelopmentandrapidurbanizationresultedinwetlandshrinkageanddegradation,seriousshortageofWetlandswater,thedeteriorationofwaterenvironment,seriousdamagetoecologicalfunctionsofwetlands,biodiversitydecline,andsignificantpotentialhydro-ecologicalcrisis[6].Thearea'sunique“threelongitudinalandtwolatitudinal”wetlandpatternformsasystemcomposedofdifferentsub-systemsincludingrivers,lakes,andestuaries.Differentsubsystemshavedifferentspatialpatterns,anddramaticchangeshavetakenplacedrivenbytherapiddevelopmentofsocialeconomyanddramaticchangesofclimateinthelast30years,thereisanapparentresponsetotheecologicalenvironment.Bycomparingthesimilaritiesanddifferencesofdiffe