Wang Xinxin, Xiao Xiangming, Zou Zhenhua, Hou Luyao, Qin Yuanwei, Dong Jinwei, Doughty Russell B, Chen Bangqian, Zhang Xi, Chen Ying, Ma Jun, Zhao Bin, Li Bo
Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science and Institute of Eco-Chongming (IEC), Fudan University, Shanghai 200433, China.
Department of Microbiology and Plant Biology, Center for Spatial Analysis, University of Oklahoma, Norman, OK 73019, USA.
ISPRS J Photogramm Remote Sens. 2020 May;163:312-326. doi: 10.1016/j.isprsjprs.2020.03.014. Epub 2020 Mar 2.
Coastal wetlands, composed of coastal vegetation and non-vegetated tidal flats, play critical roles in biodiversity conservation, food production, and the global economy. Coastal wetlands in China are changing quickly due to land reclamation from sea, aquaculture, industrialization, and urbanization. However, accurate and updated maps of coastal wetlands (including vegetation and tidal flats) in China are unavailable, and the detailed spatial distribution of coastal wetlands are unknown. Here, we developed a new pixel- and phenology-based algorithm to identify and map coastal wetlands in China for 2018 using time series Landsat imagery (2,798 ETM+/OLI images) and the Google Earth Engine (GEE). The resultant map had a very high overall accuracy (98%). There were 7,474.6 km of coastal wetlands in China in 2018, which included 5,379.8 km of tidal flats, 1,856.4 km of deciduous wetlands, and 238.3 km of evergreen wetlands. Jiangsu Province had the largest area of coastal wetlands in China, followed by Shandong, Fujian, and Zhejiang Provinces. Our study demonstrates the high potential of time series Landsat images, pixel- and phenology-based algorithm, and GEE for mapping coastal wetlands at large scales. The resultant coastal wetland maps at 30-m spatial resolution serve as the most current dataset for sustainable management, ecological assessments, and conservation of coastal wetlands in China.
由沿海植被和无植被潮滩组成的沿海湿地在生物多样性保护、粮食生产和全球经济中发挥着关键作用。由于填海造地、水产养殖、工业化和城市化，中国的沿海湿地正在迅速变化。然而，目前尚无中国沿海湿地（包括植被和潮滩）的准确且最新的地图，沿海湿地的详细空间分布也不清楚。在此，我们开发了一种基于像素和物候的新算法，利用时间序列陆地卫星图像（2798幅ETM+/OLI图像）和谷歌地球引擎（GEE）来识别和绘制2018年中国的沿海湿地地图。生成的地图总体精度非常高（98%）。2018年中国沿海湿地面积为7474.6千米²，其中包括5379.8千米²的潮滩、1856.4千米²的落叶湿地和238.3千米²的常绿湿地。江苏省拥有中国最大面积的沿海湿地，其次是山东、福建和浙江省。我们的研究证明了时间序列陆地卫星图像、基于像素和物候的算法以及GEE在大规模绘制沿海湿地方面的巨大潜力。生成的30米空间分辨率的沿海湿地地图可作为中国沿海湿地可持续管理、生态评估和保护的最新数据集。
