Monitoring the cyanobacterial blooms based on remote sensing in Lake Erhai by <i>FAI</i>

Abstract

利用19992014年Landsat卫星遥感影像数据,采用浮游藻类指数(FAI)方法识别、提取洱海蓝藻水华信息,进而获取蓝藻水华时空分布数据,为进一步分析洱海蓝藻水华发生规律及监测预警提供参考. 结果表明:19992014年洱海夏、秋季多次发生蓝藻水华,以小型水华为主(水华面积在10 km²以内),大型水华现象主要发生在2003、2006、2013年,其中2006年水华面积最大,达到42 km².除近岸湖湾区域容易产生蓝藻堆积外,洱海蓝藻大型水华主要发生在洱海北部和中部区域,南部发生频次较少.近岸区域蓝藻堆积从春季开始,中心水域水华发生在夏末和秋季(811月),其中大型水华集中发生在10月左右.;Based on Landsat satellite remote sensing imageries, cyanobacterial blooms in Lake Erhai during 1999 to 2014 were extracted by floating algae index (FAI) algorithm. According to the results, spatio-temporal distribution of cyanobacterial blooms was analyzed for the exploration of general regularity, long-term monitoring and early-warning. The results indicated that (1) cyanobacterial blooms mainly broke out in summer and autumn between 1999 and 2014, and almost at small scales. Large-scale blooms only occurred in the year of 2003, 2006 and 2013, with the maximum area of 42 km² in 2006. (2) Blooms were usually observed in the nearshore area and bays, but the northern and central regions were the area where large-scale cyanobacterial blooms broke out most frequently, while blooms in southern region broke out less. (3)Blooms in nearshore area broke out in spring, while in the central region generally broke out in later summer and autumn (from August to November). Moreover, large-scale and long-time lasted algal blooms were usually found around October.