漳江口湿地变化的遥感监测

Remote sensing monitoring of Zhangjiang Estuary Wetland

以漳江口红树林国家级自然保护区(以下简称保护区)为研究对象,2000、2005、2010和2016年的Landsat TM/OLI影像为数据源,通过面向对象随机森林分类法对保护区湿地进行分类,分类结果总体精度达到94.45%,Kappa系数为0.931 2,表明该方法在湿地分类方面具有较大应用潜力。应用遥感技术研究保护区湿地分布及其变化,结果表明:2000—2016年,养殖池分布面积最大,大部分分布在漳江的南北两侧;护花米草主要分布在漳江南部,少量生长在漳江北部;红树林主要分布在漳江南侧,互花米草的东部,漳江北部的养殖池边缘也有少量分布;滩涂与养殖池、互花米草、红树林接壤,分布在漳江两侧。2000—2005年,保护区内的大量天然湿地向人工湿地转化,主要是滩涂湿地及其他类型转换为养殖池,变化发生在保护区南部以及中部,另有部分互花米草转换为养殖池,发生在保护区北部; 2005—2016年,互花米草面积迅速增加,主要发生在漳江南部。引起变化的主要原因是人类活动、气候因素及海平面上升。

Taking the Zhangjiangkou National Mangrove Nature Reserve as the research object,using Landsat TM/OLI images in2000,2005,2010 and 2016 as data sources,the reserve was classified by object-oriented random forest classification and the overall accuracy of the classification results reached 94.45%,and the Kappa coefficient was 0.931 2,indicating that the method has great application potential in wetland classification. In addition,remote sensing technology were introduced to study the distribution and change of wetland in protected area,the results showed that the distribution area of the culture ponds was the largest during2000—2016,most of them were distributed on the north and south of Zhangjiang River. The Spartina alterniflora were mainly distributed in the south of Zhangjiang River and partly of S. alterniflora growing in the north of Zhangjiang River. Mangroves were mainly distributed in the south of Zhangjiang River and in the east part of S. alterniflora,and there is also a small amount of distribution at the edge of culture ponds in the northern Zhangjiang River; the tidal flats were bordered by the breeding ponds,S. alterniflora and mangroves,distributed along the both sides of Zhangjiang River. During 2000—2005,a large number of natural wetlands including tidal flats or the other wetlands in the protected area were converted to culture ponds. The change occurred in the southern and central part of the protected area,and some of the S. alterniflora were converted into breeding ponds. S. alterniflora area increased rapidly from 2005 to 2016,mainly in the south part of Zhangjiang River. The main causes of change include human activities,climatic factors and rising sea levels.