Monitoring mangrove reforestation in Madagascar with Sentinel 2 derived spectral indices

Mangroves play a crucial role in carbon sequestration, coastal protection, and biodiversity. The efficacy of mangrove reforestation projects is important for environmental management and conservation efforts around the world. This study evaluates the use of spectral indices derived from Sentinel-2 data to monitor mangrove reforestation. Specifically, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index 2 (EVI-2), Red Edge Normalized Difference Vegetation Index (RedEdge NDVI), and Mangrove Vegetation Index (MVI) were analyzed across two study areas: Tsimipaika Bay and Assassin's Bays. Our findings indicate that all four indices were capable of detecting change in mangrove reflectance, but differed in their relative efficacy. The research underscores the complex interaction between mangrove growth, reforestation area size, and the effectiveness of different spectral indices in remote sensing. Recommendations for future studies include refining data extraction methods to enhance change detection and to consider seasonal variations to mitigate the influence of vegetation saturation. This study contributes to the optimization of monitoring strategies for mangrove reforestation, offering insights into the scalability and applicability of remote sensing techniques in conservation efforts.

红树林在碳封存、海岸防护及生物多样性保护中发挥着关键作用。红树林造林项目的实施成效，对全球环境管理与保护工作而言至关重要。本研究针对由Sentinel-2卫星数据衍生得到的光谱指数在红树林造林监测中的应用展开评估。具体而言，研究选取齐米帕卡湾（Tsimipaika Bay）与刺客湾（Assassin's Bays）两个研究区域，对归一化差异植被指数（Normalized Difference Vegetation Index，NDVI）、增强型植被指数2（Enhanced Vegetation Index 2，EVI-2）、红边归一化差异植被指数（Red Edge Normalized Difference Vegetation Index，RedEdge NDVI）以及红树林植被指数（Mangrove Vegetation Index，MVI）进行了分析。研究结果显示，上述四种光谱指数均可检测红树林反射率的变化，但各自的相对效能存在差异。本研究凸显了红树林生长、造林区域面积与不同遥感光谱指数效能之间的复杂交互关系。针对后续研究，本文建议优化数据提取方法以提升变化检测精度，并考虑季节变化因素以缓解植被饱和的影响。本研究有助于优化红树林造林监测策略，为遥感技术在保护工作中的可扩展性与应用适用性提供了科学见解。