江苏近岸辐射沙洲潮滩变化遥感监测研究

潮滩是动态的后备土地资源，具有重要的生态价值和经济价值。为了实现潮滩的大范围遥感监测，选择江苏近岸辐射沙洲作为研究区，以HJ 1A/1B和Landsat系列卫星影像数据为数据源，基于遥感水边线集合的最外边界方法确定潮滩范围，实现了2009～2017年的潮滩面积提取以及变化分析。结果表明：研究区2009～2017年潮滩面积减少量约为219.83 km²，减幅8.7%。在2009～2014年研究区潮滩淤长面积8.35 km²， 2014～2017年潮滩蚀退面积达228.88 km²，减幅9.18%。在2009~2017年，辐射沙洲北翼岸段和南翼岸段主要表现为侵蚀特征，內缘区和中部岸段表现为冲淤交替特征。该方法可以实现大范围、复杂地貌潮滩监测，为江苏省潮滩资源的合理开发利用提供数据参考。

Remote Sensing Monitoring of Tidal Flat Changes Near the Radial Sand Ridges in Jiangsu Coastal Zone

As the dynamic reserve land resource, tidal flats contain significant value in both ecology and economy. In order to delineate the extent of tidal flats at a large-scale by remote sensing technology, the Radial Sand Ridges (RSR) near the coastal area of Jiangsu Province was selected as the study area. Muti-temporal satellite images, which included Chinese HJ-1A/1B and Landsite series satellite images, were used as the data source. Then, the outermost waterline method was conducted to map tidal flats of the RSR from 2009 to 2017. Finally, the spatiotemporal dynamic change analysis was implemented. The results showed that from 2009 to 2017, tidal flats of the RSR decreased by 219.83 km², a loss of 8.7%. From 2009 to 2014, the area of the tidal flats increased by 8.35 km². While, from 2014 to 2017, tidal flats in the RSR declined by 228.88 km², with a loss of 9.18%. Tidal flats in the northern and southern part of the RSR showed the trend of erosion. Additionally, tidal flats in the inner and the middle part of the RSR flushed and silted alternatively. Our method enables to quickly monitor tidal flats with complex geomorphology and large scale, providing data reference for rational development and utilization of tidal flat resource in Jiangsu Province.