基于卫星遥感的太湖蓝藻水华时空分布规律认识

J.LakeSci.(湖泊科学),2008,20(6):687-694http://www.jlakes.org.E-mail:jlakes@niglas.ac.cn©2008byJournalofLakeSciences基于卫星遥感的太湖蓝藻水华时空分布规律认识∗马荣华1,孔繁翔1,段洪涛1,张寿选1,孔维娟2,郝景燕1(1:中国科学院南京地理与湖泊研究所,南京210008)(2:南京大学地理信息科学系,南京210093)摘要:建立了基于多源卫星遥感影像的太湖蓝藻水华信息提取的普适模式,获取了天气晴好条件下蓝藻水华的面积和空间分布.近年来,太湖蓝藻水华暴发时间逐渐提前至3-4月,暴发的高频繁期发生在6-7月,其次是10-11月;2000年以来,蓝藻水华的持续时间有所增加,几乎全年(3-12月)都有发生.北部(梅梁湾、竺山湾)是蓝藻水华的最初暴发地,是蓝藻水华暴发的重灾区,每年都有发生;2001年以来,南部沿岸区(浙江附近水域,即夹浦新塘一带的沿岸水体)也几乎每年都有发生,且集聚面积逐年扩大,持续时间越来越长,逐渐成为太湖蓝藻的最早暴发地;2003年以来,蓝藻水华开始向湖心扩散,严重时几乎覆盖整个太湖的非水生植被区;值得注意的是,2005年以来,以前很少有蓝藻水华发生的贡湖湾,也开始有大面积蓝藻水华覆盖,2007年发生的频率显著增加.关键词:蓝藻水华;遥感;太湖Spatio-temporaldistributionofcyanobacteriabloomsbasedonsatelliteimageriesinLakeTaihu,ChinaMARonghua1,KONGFanxiang1,DUANHongtao1,ZHANGShouxuan1,KONGWeijuan2&HAOJingyan1(1:NanjingInstituteofGeographyandLimnology,ChineseAcademyofSciences,Nanjing210008,P.R.China)(2:DepartmentofGeographyInformationSciences,NanjingUniversity,Nanjing210093,P.R.China)Abstract:Ofallthecloudless340satelliteimageries11wereshotbyLandsatMSS/TM/ETMsensorsince1979,216byEOSMODISsensorsince2002,10byCEBERSCCDsensorsince2005and3byIRSP6LISS-3sensorin2007.Onthebasisofthespectralanalysis,anapplicablemodelwasdevelopedtoextractthecyanobacteriabloominformationfrommulti-sourceremotesensingimages.Andthen,themodelwasusedtoacquirecyanobacteriabloom-coveredareaanditsspatialdistribution.TheresultshowedthattheinitialtimeofcyanobacteriabloomwasmovedfromJuneorJulytoMarchorAprilatpresent,three-fourmonthsadvancedthanthenormal.ThestatisticsshowedthatthecyanobacteriabloomoccursmostfrequentlyinJuneorJulyandthesecondwasinOctoberorNovember.Additionally,thedurationofcyanobacteriabloomisbecominglongerandlongerandalmostovertimeofMarchtoDecemberatpresent.ThemostintensityofcyanobacteriabloomoccurredinSeptemberandthesecondwasinJune.ThenorthofLakeTaihu,includingMeiliangBayandZhushanBay,wastheinitiallocationofcyanobacteriabloomandalsotheheavydisasterarea,wherethecyanobacteriabloomoccurredeveryyearsinceitsfirsttime.However,cyanobacteriabloomalsooccurred