We report the damage caused by Amphan, a category five tropical cyclonic storm, to the ecology and shoreline of the Sundarban mangrove ecosystem, located in India and Bangladesh. In this study, net shoreline movement (NSM) combined with vegetation indices, such as normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI), were used to analyze land use and land cover changes and the position of the shoreline in pre- and post-cyclone periods. The results show that the cyclone wreaked havoc in the Sundarban mangrove ecosystem, causing dangerous impacts on vegetation and severe erosion along the shoreline. The impact on the Sundarban mangrove forest, shown by NDVI and EVI values, indicates that the mangrove vegetation suffered degradation and fragmentation. Dense and moderately dense mangrove tree cover area shrank from 77% to 34%, less dense and sparse cover increased from 20% to 63%. More than 68% of shoreline transects registered signs of erosion, with mean shoreline change and erosion rate measurements of −31 m and −48 m, respectively. As a result, agricultural lands and aquaculture ponds suffered inundation, leading to crop damage. A single cyclone episode can damage mangrove cover by knocking down tall trees, killing more salt-sensitive mangrove species such as Sundari, and leads to increased man-animal encounter. We argue that post-cyclone biodiversity loss and ecosystem services loss should be analyzed in tandem and synchrony with human and livestock casualty and economic damage assessment.

我们报告了五级热带气旋风暴 Amphan 对位于印度和孟加拉国的 Sundarban 红树林生态系统的生态和海岸线造成的破坏。本研究利用净海岸线运动（NSM）结合归一化植被指数（NDVI）和增强植被指数（EVI）等植被指数，分析了土地利用和土地覆盖变化以及海岸线在前期的位置。 - 和飓风后时期。结果表明，气旋对孙德尔本红树林生态系统造成了严重破坏，对植被造成了危险的影响，并严重侵蚀了海岸线。NDVI 和 EVI 值显示对 Sundarban 红树林的影响表明红树林植被遭受了退化和破碎。浓密和中密红树林覆盖面积从 77% 减少到 34%，疏密和疏密覆盖面积从 20% 增加到 63%。超过 68% 的海岸线横断面记录了侵蚀迹象，平均海岸线变化和侵蚀率测量值分别为 -31 m 和 -48 m。结果，农田和水产养殖池塘被淹没，导致农作物受损。单一的气旋事件会摧毁高大的树木，杀死更多对盐分敏感的红树林物种，例如 Sundari，并导致人与动物的遭遇增加。我们认为，飓风过后的生物多样性损失和生态系统服务损失应与人类和牲畜伤亡和经济损失评估同步进行分析。超过 68% 的海岸线横断面记录了侵蚀迹象，平均海岸线变化和侵蚀率测量值分别为 -31 m 和 -48 m。结果，农田和水产养殖池塘被淹没，导致农作物受损。单一的气旋事件会摧毁高大的树木，杀死更多对盐分敏感的红树林物种，例如 Sundari，并导致人与动物的遭遇增加。我们认为，飓风过后的生物多样性损失和生态系统服务损失应与人类和牲畜伤亡和经济损失评估同步进行分析。超过 68% 的海岸线横断面记录了侵蚀迹象，平均海岸线变化和侵蚀率测量值分别为 -31 m 和 -48 m。结果，农田和水产养殖池塘被淹没，导致农作物受损。单一的气旋事件会摧毁高大的树木，杀死更多对盐分敏感的红树林物种，例如 Sundari，并导致人与动物的遭遇增加。我们认为，飓风过后的生物多样性损失和生态系统服务损失应与人类和牲畜伤亡和经济损失评估同步进行分析。单一的气旋事件会摧毁高大的树木，杀死更多对盐分敏感的红树林物种，例如 Sundari，并导致人与动物的遭遇增加。我们认为，飓风过后的生物多样性损失和生态系统服务损失应与人类和牲畜伤亡和经济损失评估同步进行分析。单一的气旋事件会摧毁高大的树木，杀死更多对盐分敏感的红树林物种，例如 Sundari，并导致人与动物的遭遇增加。我们认为，飓风过后的生物多样性损失和生态系统服务损失应与人类和牲畜伤亡和经济损失评估同步进行分析。