基于遥感反演的鸭绿江河口湿地植被覆盖度变化分析

Vegetation Coverage Change of Yalu River Estuary Wetland Based on Remote Sensing Inversion Analysis

利用1981-2019年的遥感影像数据,基于归一化植被指数的像元二分模型,对鸭绿江河口湿地植被覆盖度进行遥感反演,在此基础上分析植被覆盖度的时空演化规律。反演结果表明:1981—-2019年研究区域植被覆盖度一般在0.60~0.70,1989年植被覆盖度最高值为0.69,最近期的2019年植被覆盖度最低值为0.56,总体呈退化趋势;研究区域植被覆盖等级以80%~100%的极高等级为主,占土地总面积的50.57%,但已从极高覆盖度向高覆盖度进行转化;湿地核心区域受到人类开发活动的影响较小,其变化平稳,而周边缓冲区域的波动变化、植被覆盖度衰退的主要原因是城市化建设、港口工程建设与滩涂养殖。

Using the remote sensing image data from 1981 to 2019, based on the pixel dichotomy model of normalized vegetation index, the remote sensing inversion of vegetation coverage in the Yalu River estuary wetland was carried out, and the spatial and temporal evolution of vegetation coverage was analyzed. The results showed that the vegetation coverage in the area was generally between 0.60 and 0.70 from 1981 to 2019. The highest vegetation coverage in 1989 was 0.69, and the lowest vegetation coverage in 2019 was 0.56, showing a degradation trend. The vegetation coverage grade in the area mainly ranges from 80% to 100% which is the highest level, accounting for 50.57% of the total land area, but it has been transformed from extremely high coverage to high coverage. The change of wetland core area is stable, while the fluctuation of the surrounding buffer area and the decline of vegetation coverage are mainly due to urbanization, port construction and tidal flat aquaculture.