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江苏沿海海涂广阔,其上分布着种类众多的盐沼植被。近些年来,大范围的围垦活动导致盐沼分布发生了巨大变化,充分把握围垦活动下盐沼分布与扩张规律,可为滩涂资源开发和环境保护提供决策支持。基于此,研究结合了NDVI和局部OTSU方法通过遥感影像提取了近25 a间7个时期的江苏中部沿海的盐沼并数字化出各时期新增垦区,利用GIS技术分析了盐沼分布的时空演变并讨论了盐沼对滩涂围垦的响应。结果表明:1盐沼面积历经先增后减的过程,26 a间约减少10%,在2000年后堤外盐沼宽度与覆盖度不断降低,盐沼分布由弶港北岸多、弶港南岸少的格局逐渐转变为新洋至斗龙港口岸段多、其余海岸少的格局;2滩涂围垦造成的盐沼消亡面积达569.47 km2,占盐沼消亡总量的85.4%,对弶港以北盐沼影响极大;3潮间带的围垦活动能够改变原潮滩的沉积环境,对盐沼扩张起到了一定的推动作用,这意味着盐沼有望在围垦后得以逐步恢复,但若围垦太快,堤外余留盐沼过少,盐沼恢复将难以为继。
Jiangsu coastal vast sea, which is distributed on a wide range of salt marsh vegetation. In recent years, large-scale reclamation activities have led to great changes in the distribution of salt marshes. Fully grasping the distribution and expansion of salt marshes under reclamation activities can provide decision support for the development of beach resources and environmental protection. Based on this, the study combined the NDVI and local OTSU methods to extract salt marshes from the central part of Jiangsu Province in the past 25 years through remote sensing images and digitized new reclamation areas in each period. The temporal and spatial evolution of salt marsh distribution was analyzed by GIS The response of salt marsh to reclamation of beach was discussed. The results showed that: 1 the area of salt marsh went through the process of increase and decrease first, then decreased about 10% after 26 years. After 2000, the width and coverage of salt marsh continued to decrease. Gradually changed into a pattern with a large number of Xindyang-Dulong port sections and few remaining coasts. The disappearance of salt marshes caused by the reclamation of tidal flats reached 569.47 km 2, accounting for 85.4% of the total number of salt marshes, The reclamation activities in the tidal zone can change the depositional environment of the original tidal flat and play a certain role in promoting the expansion of the salt marsh. This means that the salt marsh is expected to gradually recover after the reclamation, but if the reclamation is too fast , Too few salt marshes outside the embankment, salt marsh restoration will be unsustainable.