10m分辨率全球红树林空间分布制图与分析

Mapping global distribution of mangrove forests at 10-m resolution

由于其独特的海陆过渡特性和极高的物质生产能力,红树林被列为国际湿地生态保护和生物多样性保护的重要对象.准确可靠的大尺度空间格局信息是红树林湿地保护与利用的重要基础.然而,现有大尺度数据集缺乏空间细节和合理的地理信息.在此,本文使用面向对象的随机森林分类方法,结合专家后处理,创建了具有时空一致性的10 m分辨率全球红树林数据集,命名为“高分辨率全球红树林(HGMF2020)”.然后,从保护、威胁和抵御海洋灾害的角度分析了全球红树林的状况.结果表明:(1) 2020年全球红树林面积为145068 km^(2),其中亚洲红树林面积最大(39.2%);(2)南亚红树林的保护比例较高,斑块整体性较高,而东亚和东南亚红树林面临严峻的威胁;(3)近99%的红树林斑块宽度大于100 m,表明几乎所有的红树林在抵御热带风暴等海洋灾害方面均有一定作用.本文提供了高精度全球红树林空间分布数据集,并分析其斑块信息,研究结果和讨论可为全球红树林生态系统的保护和合理利用提供决策依据,对于我国履行国际湿地公约、进行环境外交具有积极意义.

Mangrove forests deliver incredible ecosystem goods and services and are enormously relevant to sustainable living.An accurate assessment of the global status of mangrove forests warrants the necessity of datasets with sufficient information on spatial distributions and patch patterns.However,existing datasets were mostly derived from
30 m resolution satellite imagery and used pixel-based image classification methods,which lacked spatial details and reasonable geo-information.Here,based on Sentinel-2 imagery,we created a global mangrove forest dataset at 10-m resolution,namely,Highresolution Global Mangrove Forests(HGMF_2020),using object-based image analysis and random forest classification.We then analyzed the status of global mangrove forests from the perspectives of conservation,threats,and resistance to ocean disasters.We concluded the following:(1)globally,there were 145,068 km^(2) mangrove forests in 2020,among which Asia contained the largest coverage(39.2%);at the country level,Indonesia had the largest amount of mangrove forests,followed by Brazil and Australia.(2)Mangrove forests in South Asia were estimated to be in the better status due to the higher proportion of conservation and larger individual patch size;in contrast,mangrove forests in East and Southeast Asia were facing intensive threats.(3)Nearly,99%of mangrove forest areas had a patch width greater than 100 m,suggesting that nearly all mangrove forests were efficient in reducing coastal wave energy and impacts.This study reports an innovative and up-to-date dataset and comprehensive information on mangrove forests status to contribute to related research and policy implementation,especially for supporting sustainable development.