Abinaya R, Kantharajan G, Sajeevan M K
Department of Fisheries Resource Management, Faculty of Fisheries Science, Kerala University of Fisheries and Ocean Studies, Kochi, Kerala, 682506, India.
ICAR - National Bureau of Fish Genetic Resources, Lucknow, 226 002, Uttar Pradesh, India.
Environ Monit Assess. 2025 Jan 7;197(2):145. doi: 10.1007/s10661-024-13592-0.
Wetlands are dynamic ecosystems vital for sustaining ecological health and development at regional and global scales. Geospatial tools have emerged as essential for managing wetland ecosystems. This study assessed the spatiotemporal dynamics of water spread in the Point Calimere Wetland, a coastal Ramsar site located along the Bay of Bengal, India, from 1984 to 2023. The analysis based on Global Surface Water Explorer (GSWE) and Normalized Difference Water Index (NDWI) derived from Landsat 5, 7, and 8 data revealed that 21% of the total wetland area showed an increasing trend. In comparison, 5.7% of the area showed a decreasing trend of surface water coverage, largely driven by erosion and climatic variability. The mean water spread increased from 119.47 km (2000-2003) to 160.88 km (2020-2023), with notable seasonal fluctuations. Among all seasons, the monsoon with the highest surge (41.1%) in water dynamics reported the largest water spread in 2020-2023 (221.87 km). A moderate positive and negative relationship was noted between rainfall and water spread (r = 0.35) and temperature and water spread (r = - 0.43). A marked increase in habitat patches and edge density between 2000-2003 and 2020-2023 indicates the wetland's vulnerability to changing climatic conditions and the critical role of seawater intrusion, shoreline changes, and tidal forces in shaping its hydrological dynamics. The data presented on the historical water dynamics in this study is invaluable for the conservation planning and management of wetlands to support the associated coastal biodiversity and livelihood of the dependent communities.
湿地是动态生态系统，对维持区域和全球尺度的生态健康与发展至关重要。地理空间工具已成为管理湿地生态系统的关键要素。本研究评估了位于印度孟加拉湾沿岸的拉姆萨尔海岸湿地——卡里梅雷角湿地在1984年至2023年期间水体分布的时空动态。基于全球地表水探索者（GSWE）以及源自陆地卫星5号、7号和8号数据的归一化差异水体指数（NDWI）的分析表明，湿地总面积的21%呈现增加趋势。相比之下，5.7%的区域地表水覆盖面积呈下降趋势，这主要是由侵蚀和气候变异性导致的。平均水体分布范围从2000 - 2003年的119.47平方千米增加到2020 - 2023年的160.88平方千米，且存在明显的季节性波动。在所有季节中，水体动态变化激增幅度最大（41.1%）的季风季节在2020 - 2023年的水体分布范围最大（221.87平方千米）。降雨与水体分布（r = 0.35）以及温度与水体分布（r = -0.43）之间呈现出中等程度的正相关和负相关关系。2000 - 2003年至2020 - 2023年期间栖息地斑块和边缘密度的显著增加表明，该湿地易受气候变化影响，海水入侵、海岸线变化和潮汐力在塑造其水文动态方面起着关键作用。本研究中呈现的关于历史水体动态的数据对于湿地保护规划和管理而言具有极高价值，有助于维护相关的沿海生物多样性以及依赖湿地生存的社区的生计。
