摘要
AdetailedsurveyofthereefsintheNanshaIslands’seathatareofstrategicimportanceisconducivetotheirfuturedevelopment.Inthisstudy,atotalof50Landsat8operationallandimager(OLI)imageswereusedtoanalyzethegeologicalfeaturesandspectralcharacteristicsoftheNanshareefs.Theexposedislands/sandbanks,reefflatsandsub-tidalreefswereidentifiedwiththenear-infraredband,theredandgreenbands,andtheblueband,respectively.BasedontherelationshipsamongvariouscharacteristicsandbandsillustratedintheOLIimages,themaximumbetween-clustervariancethresholdalgorithm(OTSUmethod)andthemathematicalmorphologywereemployedtoextractcharacteristicparametersofthespatialgeometryofthereefsfromtoptobottom,whichweresubsequentlyoperatedbyaseriesofpost-processingmethodssuchasvectorization,simplificationandtopologicalanalysis.Amongthe132standalonereefsand16atollsthatareidentifiedinthestudy,fourreefshaveyettobenamedintheStandardNamesofVariousIslandsintheSouthChinaSeaandthewebsiteNanshaIslandsOnline(http://www.nansha.org/).Another24onesareexposedtotheatmosphereevenduringhightides.TaipingIslandwithanareaof0.57km~2representsthelargestexposedgeologicalfeature.Thisstudydemonstratedtheapplicabilityofmedium-resolutionsatelliteimagestoderivethecoralreefinformationeffectivelyandthusprovidedinformationfortherelateddepartmentsthatareresponsibletomanagethecoast.Animprovedresolutionofmultispectralbandswiththepanchromaticbandinhigherspatialresolution(15mforOLIimage)isexpectedtoprovideanoptimumsatellitebasedapproachtomapmarinehabitats.
出版日期
2016年10月20日(中国期刊网平台首次上网日期,不代表论文的发表时间)