基于突变理论的太湖蓝藻水华危险性分区评价

J.LakeSci.(湖泊科学),2010,22(4):488-494http://www.jlakes.org.E-mai:ljlakes@niglas.ac.cnZJournalofLakeSciences基于突变理论的太湖蓝藻水华危险性分区评价*刘聚涛1,2,高俊峰1**,姜加虎1,许妍1,2,赵家虎1,2(1:中国科学院南京地理与湖泊研究所,南京210008)(2:中国科学院研究生院,北京100049)摘要:蓝藻水华暴发是湖泊生态系统中营养物质长期累积的结果,是系统营养经长期演化后的极端状态.突变理论评价方法无需确定指标权重,减少了人为主观因素,并且计算方便.本文基于突变理论,采取蓝藻水华暴发的表征因子(叶绿素浓度)和导致蓝藻水华暴发的环境因子(总氮和总磷)作为潜在危险性评价指标,蓝藻水华的面积、范围以及暴发频次作为历史危险性评价指标建立多准则蓝藻水华暴发风险评价指标体系,并结合太湖九个分区进行蓝藻水华暴发危险性分区及全湖评价.研究结果表明:竺山湖和西部沿岸为极重危险性湖区;梅梁湾为重度危险性湖区;南部沿岸、贡湖和大太湖为中度危险性湖区;箭湖东茭咀、东太湖和胥湖蓝藻水华暴发危险性较小,为轻微危险性湖区.整体上看,太湖蓝藻水华暴发危险性程度由轻到重基本上沿东南-西北方向变化,与营养盐浓度由低到高分布趋势相一致.根据评价结果,可以明确太湖各区遭遇蓝藻水华暴发危险性的大小,为蓝藻水华风险管理和应急处理提供科学依据.关键词:蓝藻水华;风险评价;太湖;突变理论Catastrophetheory-basedriskevaluationofblue-greenalgaebloomofdifferentregionsinLakeTaihuLIUJutao1,2,GAOJunfeng1,JIANGJiahu1,XUYan1,2&ZHAOJiahu1,2(1:NanjingInstituteofGeographyandLimnology,ChineseAcademyofSciences,Nanjing210008,P.R.China)(2:GraduateUniversityofChineseAcademyofSciences,Beijing100049,P.R.China)Abstrac:tWaterbloomistheresultsoflong-termaccumulationofnutrientsinecologicalsystem,andanextremestateasaresultofeutrophicationsystemafterlong-termevolution.Theproposedmethodneednptdefinetheweightofevaluationindicessothatthein-fluenceofsubjectivefactorsonassessmentcanbeminimized.Basedoncatastrophetheory,thispapertakeswaterchlorophyl-lacon-centrationascharacterizationfactorofblue-greenalgaebloomoutbreakdegree,totalphosphorusandtotalnitrogenconcentrationastheenvironmentalfactorsofpotentialriskevaluationindexes,andblue-greenalgaebloomarea,extentandfrequencyasthehistoricalriskevaluationindexes.Theseparameterscanbeusedtoestablishamult-icriteriariskevaluationindexsystemforblue-greenalgaebloomoutbreak.ItcarriesouttheriskevaluationcombinedwithdifferentregionsinLakeTaihu.TheresultsshowthattheriskinthewesterncoastofLakeZhushan,isthemostserious,heavyinMeiliangBay,moderateinsoutherncoastofGonghuandLargeTaihu,andalmostnoneseriousinLakeJianhu,EastLakeTaihuandLakeXuhu.Ingenera,lthedegreesofblue-greenalgaebloomriskinLakeTaihuarefromlighttoheavychangesfr