将lAndSAT MSS/TM/ETM数据与中国环境与灾害监测预报小卫星(HJ-1A/b)数据相结合,同时融合光谱信息、地学特征、纹理特征等多种信息,利用最大似然分类方法,提取了以福建省九龙江口红树林省级自然保护区为重点的九龙江口从20世纪70年代至2010年近40年间红树林面积的变化信息.结果表明九龙江口红树林面积在近40年呈现出减少(20世纪70—80年代)、缓慢增加(20世纪80—90年代)以及大幅度增长(2000年以后)3个主要阶段.其中人为活动(围垦、人工造林等)是九龙江口红树林面积大幅震荡的关键因子.By using the data of LANDSAT MSS/TM/ETM satellite and the Chinese environment and disaster monitoring satellite HJ-1A/B,the areal variation of mangrove coverage in the Jiulongjiang Estuary of Fujian province was investigated.Five multi-bands images were collected in 1976,1983,2002,2006 and 2010,respectively.The approach of maximum likelihood classification was used to detect mangrove from the images.It was found that the area of mangrove was likely decreasing during the period of 1970s-1980s(--60% drop).Recovery initiated during 1980s-2000s,and significant spread of mangrove occurred in the 2000s.The area of mangrove coverage in 2010 in the study region was about two times of the value in 1983.Such a highly variable temporal pattern was clearly different from that expected under natural forcing(--+4% annual change),suggesting that it was predominantly induced by human activities.国家重点基础研究发展计划(973)前期研究专项(2009CB426306
