简介:南麂岛位于浙江省平阳县鳌江口外30海里的东海海面上,是南麂列岛52个岛屿中最大的岛屿。1990年南麂岛被列为我国首批国家级海洋类自然保护区,4A级旅游景区,是中国最美海岛之一。南麂岛由众多岛礁构成,海岸线曲折,海湾众多,受海浪和潮汐的侵蚀冲击,岛上基岩裸露,多呈陡崖峭壁。著名景点有'大沙澳''美龄居''虎屿'等。
简介: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.
简介:InwesternSongnenPlainofChina,thesaline-alkalinedegreeofwaterbodiesishighinsaltmarshwetlands.Generally,pHisabove8.0,andthehydrochemicaltypesbelongtoHCO32--Na+.ThroughanalysisonthebasicsalinevariablessuchasCO32-,HCO32-,Cl-,Ca2+,Mg2+,SO42-,Na+,andthederivativevariablessuchasSAR,SDR,RSC,SSP,therelationshipsbetweendifferentvariablesarefound,andthediscriminantequationsareestablishedtoidentifydifferentsaline-alkalinewaterbodiesbyusingprincipalcomponentanalysis.
简介:一、地震基本参数表1 地震基本参数表发震时间年月日时分秒震 中 位 置微 观宏 观东经北纬东经北纬参考地名震级(MS)震源深度(Km)震中烈度 地震类型 199202181916139119°40′25°01′南日岛东南5215Ⅵ孤立型 地震发生于海中,未能确定宏观震中,震中烈度亦为经验估计。二、地震烈度分布地震宏观调查工作仅限于陆地上进行,最高烈度为Ⅴ度,等震线呈向北西突出的弧形(见图13-1)。图13-1 1992年2月18日南日岛地震等震线图 Ⅴ度区:Ⅴ度等震线北起平潭岛南端的钱便澳,向西经过福清东瀚南侧,再逐渐向南拐,通过莆田埭头的汀港,到平海东面入海。在Ⅴ度区内,室内的人普遍感到
简介:Landscapeindicesarepopularforthequantificationoflandscapepattern.Butalllandscapeindicesbeingusedsofararescalarquantity,whichmeasurepatternswithoutconsideringsufficientlythepatternsizeandthedirectionalitytogether.Basedonplanarcharacteristicsdefinedinmechanicssuchascentroid,momentofinertia,productofinertia,principalaxesandsoon,vectoranalysistheoryonlandscapepattern(VATLP)isexploredhere.Firstlyweestablishacoordinatesystemofcentroidalprincipalaxes(CSCPA)ofapatchorpatches.Somerelatednewindicesincludingthosedescribingthedirectionofpatterndistribution(patchorientation(PO),vectorialpatchorientation(VPO)),andthoseindicatingtheshapeofpatch'sequivalentellipse(majoraxis(MJA),minoraxis(MIA)andeccentricrate(ER))arededuced.TheselandscapemetricsarethenappliedtothepatternanalysisofSanjiangplainmarsh,thestudyarea.Twotemporalvector-baseddatasetsofthestudyareacomefrominterpretationofremotesensingimagesMSS(1980)andTM(2000).TheapplicationofthetheorycapturessomeshapepropertiesofriparianwetlandinSanjiangplainmarsh.ThedissymmetriealfeatiresofSanjiangplainmarsharoundprincipalaxesduetoagriculturaldevelopmentcouldalsobeexplained.
简介:特征和土壤的潮汐的扁平的趋势有机物(SOM)周转在长江河口为Chongmingdongtan盐沼被学习基于稳定的碳同位素作文(未13C)的分析,谷物微粒缩放并且满足器官的碳(停靠港),全部的氮(TN)和为从高潮汐的扁平的、中间的潮汐的公寓和赤裸的公寓挖掘的三个核心的无机的碳(TIC)。结果证明在土壤停靠港内容和盐沼核心的未13C价值之间的关联类似于在器官的碳(SOC)内容和未13C与不同高度多山的土壤侧面的上面的土壤层珍视的土壤之间的那些。盐沼的SOM通常比100年年轻,并且在长江的集水主要从表层土侵蚀发源。有C/N比率,满意于TIC内容的停靠港和停靠港的TN内容的关联与未13C价值满足因为核心建议从盐沼的SOM的周转度是全面的低,并且SOM周转的趋势从赤裸的公寓是清楚的到高潮汐的公寓。暴露原来的沉积的扁平的样品表演特征,与次要的SOM周转。SOM的周转过程发生了并且在高、中间的潮汐的公寓,和有有泥泞潮汐的公寓的进化的不同周转率增加的SOM分隔空间的混合的度是可辨别的。交替的泥泞薄片和淤泥的薄片的独占的阶层结构在泥泞潮汐的公寓上从动态depositional过程发源是到溶解材料,和SOM周转的垂直移植的一个大障碍然后被抑制。泥泞潮汐的扁平的过程在盐沼对SOM的隐遁和周转施加了直接影响,并且在长江河口在Chongmingdongtan盐沼的SOM周转的空间、时间的特征上有大限制。
简介:本文采用MIKE21二维水动力模型模拟了南黄海辐射沙脊群海域的潮流形态和含沙量,模拟结果与实测数据基本一致。在此基础上,模拟计算了围填海工程后辐射沙脊群海域的潮流和含沙量变化。结果显示工程对潮流和含沙量的影响主要出现在工程区附近。围填海工程使原本以弶港为中心呈扇形辐聚、辐散的潮流格局有所改变,形成东沙岛西侧南北向和高泥岛南侧东西向的两条潮流通道,并在一定程度上分割了条子泥南北两侧的水体。工程后含沙量的变化与平均流速的变化基本一致,在流速变大的东沙岛西北侧和高泥岛南侧海域,含沙量显著升高;在流速变小的条子泥南北两侧、东沙岛东侧及西南侧,含沙量显著降低。
简介:Anintactalkalimarshsoil(MS)coreandanagriculturesoil(AS)corewerestudiedbythesimulatedtestinordertogetthecomparisonofthenutrientsretentioninalkaliMSandAS.ThesoilcoresextractedfromtheXianghaiWetland,westernJilinProvince,China,wereleachedwithsolutioncontainedcarbon,nitrogenandphosphorus.Thentheeffluentwaterfromtheoutletsofsoilcorewithdifferentdepthswasmeasured,includingchemicaloxygendemand(COD),totalphosphorus(TP),phosphate(PO3-4-P)andnitrogenexistedasnitrate(NO-3-N),nitrite(NO-2-N)andammonianitrogen(NH+4-N)andthetotalnitrogen(TN)intheeffluentwater.CODandTParedecreasedwiththedepth,thechangingtrendsofTN,NO-3-NandNH+4-NcontentsaresimilartoCODandTP,whereasNO-2-NinbothMSandASeffluenthavealittletransitionat40cmdepth.ItissimilarefficiencyofMStoASinsignificantlycuttingdownCOD,TP,PO3-4-P,TN,NO-3-N,NH+4-NandNO-2-Ninnutrientwater.ThefunctionofMSwouldbesameefficiencyofthenutrientsretentionastheAS.AlthoughtheSOMandpHhavesomeimpactsonnutrientsretentioninthesoil,theMSwithhighersoilorganicmatter(SOM)andpHhavethesameeffluentwaterastheASwiththelowerSOMandpHatthedepthof60cm,thebottomofthesoilcores.
简介:摘要成都地铁1号线南延线四河站由单岛双线车站变为双岛四线车站,车站方案需同时满足初期主线与支线贯通运营、近期主线与支线采用主支线Y型交路运营、远期支线继续延长进而拆分为独立运营线路的各种条件;车站站厅层、站台层公共区及设备区的布置,以及防火防烟分区、消防疏散的计算均须满足规范要求。
简介:Floodingtimingandfrequencymayhavedifferenteffectsonthegrowthandcarbonmetabolismofplantsinwetlands.WetestedthishypothesisusingthreemarshplantsinSanjiangPlain,whichweregrowingindifferentfloodingtimingandfrequencyenvironmentsfor24days.Thethreemarshplantsindifferentelevationsalongawater-levelgradient,high-elevationspeciesCalamagrostisangustifolia,mid-elevationspeciesCarexlimosaandlow-elevationspeciesCarexlasiocarpa.Ourexperimentincluded6kindsoftreatments:control,longerfloodingtiming,medialfloodingtimingandfrequency(2treatments),andhigherfloodingfrequency(2treatments).LongerfloodingtimingandhigherfloodingfrequencytreatmentsledtosimilarreductionsinbiomassaccumulationandrelativegrowthrateofCalamagrostisangustifolia,whereasgrowthofCarexlimosawasnotaffectedbyeitherfloodingtimingorfrequency.However,biomassaccumulationandrelativegrowthrateofCarexlasiocarpawasonlyreducedbythehigherfloodingfrequency.StarchandsolublesugarcontentsofCalamagrostisangustifoliawerenegativelyaffectedbyfloodingfrequency.OnCarexlimosa,higherfloodingfrequencyresultedinhigherstarchcontent,butlongerfloodingtimingledtoaccumulatedstarchcontentinCarexlasiocarpa.SolublesugarcontentsofCarexlasiocarpaandCarexlimosawerenotaffectedbyeitherfloodingtimingorfloodingfrequency.Theseresultsindicatedthatgrowthresponsesofthethreemarshplantstofloodingtimingandfrequencywascloselyrelatedtothedifferentphysiologyofcarbohydratemetabolism.