近20a来我国红树林资源变化遥感监测与分析

Remote Sensing Monitoring and Analysis of the Changes of Mangrove Resources in China in the Past 20Years

选择除港澳台外我国现有红树林分布的浙江省、福建省、广东省、广西壮族自治区和海南省作为研究区域,以1990年前后的Landsat-5TM影像、2000年前后的Landsat-7ETM+影像、2010年前后的HJ-1CCD影像共计48幅为主要数据源,采用卫星遥感调查与现场调查相结合的方法,开展红树林信息提取,分析了3个时期的红树林状况和20a间的红树林变化情况。结果表明:近20a来我国红树林呈现不断增加的趋势,1990年前后、2000年前后和2010年前后红树林面积分别为13 519.6,16 053.6和24 578.2hm2;分布由沿岸分散分布趋于保护区集中分布;天然林减少,人工林增加。围填海是造成红树林面积减少的主要原因,自然保护区是红树林面积增加的主要区域。

By choosing the provinces where mangroves are distributed, such as Zhejiang, Fujian, Guang- dong, Guangxi and Hainan, as the study area, and taking the remote sensing images acquired respectively by Landsat-5 TM, Landsat-7 ETM＋ and HJ-1 CCD around 1990, 2000 and 2010 as the data sources, the information about mangroves is extracted and the status of mangrove resources in three periods and their changes in the past 20 years are analyzed by combining the satellite remote sensing surveys with the field in-situ surveys. It is found that the mangroves in China tend to increase constantly in the past 20 years, with their area being 13 519.6 hm2 around 1990, 16 053. 6 hm2 around 2000 and 24 578. 2 hm2 around 2010. Their distributions show scattered along the coast and tend to concentrate in the nature reserve, of which the natural mangroves decrease and the artificial ones increase. The reclamation of the sea is the main reason for the reducing of mangroves. The best way to increase mangroves is to establish the nature reserve.