渤海湾海岸带近现代地质环境变化

3(,300170)10102a,-(),,150000,,,(2D),,,1,,,,,(),(150000),,80,-,,,,2,,:43E2mail:[e-mail]3(:1002010940199201054)2001-05-20,2001-12-3022220023QUATERNARYSCIENCESVol.22,No.2March,2002©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.[14]-[4,5],,10102a,-[69],,(geo2environmentalchanges),,,,1()()8000km2MAPGIS1267;PCI18,(falsecolorcomposite)(scale);11345,(J50E005015)-(J50E008015J50E009015)150000(210Pb137Cs241Am),1Table1ListofthevariousgraphicdatausedfortopographiccomparisononthewestcoastofBohaiBay/km21,100011400001870[10]2,80001500001918192419283,800011000002070197319854-,120012500020502050605-,2000140000197519796-,1200110000197519787,80001500002080901994199519988(1)MSS(2)TM,80001100000(1)1976(2)1997Landsat152312002©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(2D)(11)2),(1)20,,26km2,,(1)20,10,250km2,2.2/km2[11],3;2012(2)(2)20,80%(1)20,,(2),,2),100km2,20,,30,,1m,,,(3)7000,(chenier)[13,6,12](1),,,,,,,,2070,80,,,,12km,(oyster-reef),1040cm,57m,()(?),2080,,,,1)122).(J50E005015).20013312:©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(4),[10]20,(1)20,,,,20,(1000m),,35km,1),5km(2)2080,,()12km,,,,,(13m),,,,,4,,,,10102a,,,,1..,1964,8(3):4244432..:..:,1980.3023093..,1994,16(1):68774WangHong,VanStrydonck.ChronologyofHolocenecheniersandoysterreefsonthecoastofBohaiBay,China.QuaternaryResearch,1997,47:1922055.:.:,,..:,2001.1711846,,.:.,2000,46(3):2762877..:,1996.1031128..:,1994.171739FletcherCH.Sea2leveltrendsandphysicalconsequences:ApplicationstotheU.S.shore.EarthScienceReviews,1992,33:731091)..20014312002©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.:,1880.3704350411,,.().:,1999.2312..,1962,12:652657RECENTGEO2ENVIRONMENTALCHANGESINTHEBOHAIBAYCOASTZhongXinbaoKangHui(TianjinInstituteofGeologyandMineralResources,ChinaGeologicalSurvey,Tianjin300170)AbstractGeologicalenvironmentalchangesduringtherecenttimeintheBohaiBaymuddycoasthavebeenverystriking.Themaincharacteristicsare:decreaseofwetlandsandmarshes,destructionofcheniersandoysterreefs,landwardrecessionoftheMHWSTshorelineandseawardprogradationoftheMLWSTshoreline(i.e.wideningoftheintertidalzone),verticalaccumulationofmudandfinesandontheintertidalflatandinestuaries,andextensionofcitiesandtowns.Thesechanges,usuallyonthescaleof10to102a,aredifferentfromeitherthefastchangeslikeearthquake,slideandmudfloworlong2lifegeologicalprocesses,suchasdevelopmentofcheniersandoysterreefswhichneedatleastseveralhundredyears.We,thus,calledtheseten2tohundred2year2changesastherelativelyfastchanges,beingeasilyperceivedbyoneortwogenerations.TheseareindeedevenmoredangerousthanthoseinstantaneousdisastersandlongtimeprocessesforthemuddycoastalzoneswherehavebeendenselypopulatedandmosteconomicallydevelopedbothinChinaandontheworld.Onthebasisofshallow2stratageologicalmapping(150,000),includinghigh2resolutionEijkelkamphandaugerinvestigationforthemid2andlateHolocenecoastalmuddysediments,systematicdigitalprocessingwascarriedoutbyusingMAPGISandPCIsoftwaresforthemapsoftheperiod19151989withvariousscalesfrom1100,000,150,000to110,000,andtheTM/MSSimagesofremotesensingoftheperiod19761997withthescale1100,000.Thissystematicworkwasrefinedbyasetofaerophotosof1950sand1970s,respectively.Consequently,twodimensional(2D)vectorialpictureswereobtained.Throughcomparisons,thesepicturesshowremarkablegeo2environmentalchangesalongtheBohaiBaycoastinthepasthundredyears,including1)theareaofthenaturalwetlandandmarshes/lagoonsdecreasedby50%;2)astwofamouscomponents,thecheniersandoysterreefswereseriouslydamaged;3)theshorelineofthemeanhighwaterspringtide(MHWST)hasbeenretreatedforseveralhundredmeterswhiletheshorelineofthemeanlowwaterspringtide(MLWST)hasbeenextendedfartherseaward.Theintertidalzonewaswidenedfrom3to5km;and4)citiesandtownsdramaticalllyextended.AsapartoftheexistingcoastalgeologicalmappinginvestigationsalongtheBohaiBaycoast,thedigitalprocessingofvariousmapsandtopographicimagesisusefulforthecoastalsustainabledevelopmentandinfrastructuremanagement.Keywordscoastalzone,geo2environmentalchanges,digitalprocessing5312:©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.©1994-2009ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.