2000—2020年江苏省如东海岸线与滩涂围垦时空演变及影响机制

利用8景遥感影像及土地利用数据,基于DSAS数字岸线分析法、改进的水体指数法（MNDWI）等,分析了江苏省如东县2000—2020年海岸线及滩涂围垦时空动态特征,结合围垦地区土地利用方式变化提取了海岸线与围垦变化的相关性,并阐述了其变迁原因与影响机制。结果表明：在自然与人为因素共同作用下,2000—2020年如东县海岸线整体呈现增长趋势,21年来海岸线延长了18.79 km,同时以63.84 m/a（EPR）和74.47 m/a（LRR）的速度向海扩张。至2020年为止如东县共围垦滩涂及海域46359.53 hm²,陆地面积增加9089.25 hm²,2010—2015年陆地面积扩张速度最快。围垦面积与海岸线长度呈显著正相关关系,港口建设是影响海岸线变化最显著的土地利用方式,其次为未利用地、盐场和养殖用地。

Spatio-temporal evolution and influence mechanism of shorelines and tidal flat reclamation during 2000-2020 in Rudong,Jiangsu province

Research on the characteristics and reasons of the shorelines' spatio-temporal evolution is of great significance for remote sensing monitoring, coastal resources sustainable utilization, and ecological environment management of the coastal zone. With the remote sensing and GIS technology, based on 8 remote sensing images and land use data from 2000 to 2020, etc., the digital shoreline analysis system (DSAS), modified normalized difference water index (MNDWI), and Pearson correlation coefficient method were used in this study. The spatio-temporal dynamic characteristics of shorelines and tidal flat reclamation area, combined with the change of land use in the reclamation area, extracted the correlation characteristics of the shorelines and reclamation changes from 2000-2020 were studied, and the reason and impact of their changes were analyzed. The results indicated that the shorelines of Rudong in Jiangsu province showed an overall growth trend during 2000-2020. In the last 21 years, the shoreline has been extended by 18.79 km, and at the same time it has expanded to the sea at a rate of 63.84 m/a (end point rate, EPR) and 74.47 m/a (linear regression rate, LRR) respectivily, which reflected the obvious spatial difference. Until 2020, 46,359.53 hm² of tidal flats have been reclaimed in Rudong, and the land area increased by 9089.25 hm². The land area expansion rate was the largest from 2010 to 2015. Among the seven types of land use in the reclamation area (farmland, aquafarm land, residential land, unused land, other land for construction, salt farmland and port), the area of farmland and other land for construction showed an increasing trend while the area of unused land showed a decreasing trend. The reclamation area has a significant positive correlation with the length of the shorelines. Port construction significantly affected shoreline variation, followed by unused land, salt farmland, and aquafarm land. The expansion of coastal cities and the implementation of coastal management policies played an important role in guiding and promoting changes in shorelines and reclamation activities. This research aims to provide accurate basic data support and decision-making basis for the sustainable development management and protection of coastal resources in Jiangsu.