基于MODIS数据的太湖蓝藻水华时空分布规律研究

利用EOS/MODIS遥感影像数据,采用蓝藻水华分级评价方法和蓝藻水华发生频率分析方法,对2010年～2013年不同级别太湖蓝藻水华时空分布规律进行分析和研究,以期为太湖蓝藻水华预警、监控、治理工作提供技术支持.结果表明：（1） 2010年～2013年,全太湖共发生蓝藻水华354次,其中小型水华发生次数最多,蓝藻水华级别越高,发生次数越少.（2）年际变化上,蓝藻水华发生次数总体趋于平稳,蓝藻水华发生呈现“小型多发、中大型少发、重大型偶发”趋势,蓝藻水华发生规模呈显著缩小趋势.（3）月际变化上,蓝藻水华主要发生在8 ～10月,8月和9月尤其是太湖蓝藻水华的高发月份.发生规模上,4～6月蓝藻水华发生规模较小,7月开始规模逐步扩大,到9月达到顶峰,10月规模有所缩小.（4）空间变化上,太湖西部沿岸是太湖蓝藻水华首次爆发最频繁的水域.从空间分布频率来看,太湖西部沿岸区尤其宜兴沿岸是蓝藻水华爆发频率最高的水域.

Research on Spatial and Temporal Distribution of Blue-green Algae Blooms Based on MODIS Data in Lake Taihu

Based on EOS/MODIS remote sensing data,this paper studied spatial and temporal distribution of different scale of blue-green algae blooms in Lake Taihu between 2010 and 2013 by grading evaluation method and frequency of occurrence analysis method,attempting to provide technical support for early warning,monitoring and management of blue-green algae bloom in Lake Taihu.The results indicated that blue-green algae blooms broke out 354 times in Lake Taihu between 2010 and 2013,small-scale blooms broke out most,and higher scale of blue-green algae blooms happened less.The annual trend of occurrence time of blue-green algae blooms stays stable,which is ＂ small scale happened more,medium scale happened less and large scale happened occasionally＂.The scale of blue-green algae blooms reduced dramaticlly.The monthly trend showed that the occurrence of blue-green algae blooms was mainly during August to October,especially in August and September.The trend of scale showed that blue-green algae blooms was relatively small from April to June,and then gradually expanded in July,peaked in September,and then reduced in October.The spatial trend showed that,the west side of Lake Taihu especially Yixing bank was the area where blue-green algae blooms broke out most frequently.