Wang Xinxin, Xiao Xiangming, Zou Zhenhua, Chen Bangqian, Ma Jun, Dong Jinwei, Doughty Russell B, Zhong Qiaoyan, Qin Yuanwei, Dai Shengqi, Li Xiangping, Zhao Bin, Li Bo
Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai 200433, China.
Department of Microbiology and Plant Biology, Center for Spatial Analysis, University of Oklahoma, Norman, OK 73019, USA.
Remote Sens Environ. 2020 Mar 1;238. doi: 10.1016/j.rse.2018.11.030. Epub 2018 Dec 5.
Tidal flats (non-vegetated area), along with coastal vegetation area, constitute the coastal wetlands (intertidal zone) between high and low water lines, and play an important role in wildlife, biodiversity and biogeochemical cycles. However, accurate annual maps of coastal tidal flats over the last few decades are unavailable and their spatio-temporal changes in China are unknown. In this study, we analyzed all the available Landsat TM/ETM+/OLI imagery (~ 44,528 images) using the Google Earth Engine (GEE) cloud computing platform and a robust decision tree algorithm to generate annual frequency maps of open surface water body and vegetation to produce annual maps of coastal tidal flats in eastern China from 1986 to 2016 at 30-m spatial resolution. The resulting map of coastal tidal flats in 2016 was evaluated using very high-resolution images available in Google Earth. The total area of coastal tidal flats in China in 2016 was about 731,170 ha, mostly distributed in the provinces around Yellow River Delta and Pearl River Delta. The interannual dynamics of coastal tidal flats area in China over the last three decades can be divided into three periods: a stable period during 1986-1992, an increasing period during 1993-2001 and a decreasing period during 2002-2016. The resulting annual coastal tidal flats maps could be used to support sustainable coastal zone management policies that preserve coastal ecosystem services and biodiversity in China.
潮滩（无植被区域）与沿海植被区域共同构成了高低水位线之间的沿海湿地（潮间带），并在野生动物、生物多样性和生物地球化学循环中发挥着重要作用。然而，过去几十年间缺乏精确的沿海潮滩年度地图，其在中国的时空变化也尚不明确。在本研究中，我们利用谷歌地球引擎（GEE）云计算平台和一种强大的决策树算法，分析了所有可用的陆地卫星TM/ETM+/OLI影像（约44528幅图像），以生成开放水体和植被的年度频率地图，从而制作出1986年至2016年中国东部沿海潮滩的年度地图，空间分辨率为30米。利用谷歌地球中可用的超高分辨率图像对2016年生成的沿海潮滩地图进行了评估。2016年中国沿海潮滩总面积约为731170公顷，主要分布在黄河三角洲和珠江三角洲周边省份。过去三十年中国沿海潮滩面积的年际动态可分为三个时期：1986 - 1992年为稳定期，1993 - 2001年为增长期，2002 - 2016年为减少期。生成的年度沿海潮滩地图可用于支持中国保护沿海生态系统服务和生物多样性的可持续海岸带管理政策。
