Changes of Yancheng coastline near 20 years based on remote sensing technology

Abstract

The study of coastline changes is crucial for the monitoring, development, and management of coastal environments. This article specifically focuses on the coastline of Yancheng. To analyze the changes of coastline, latest remote sensing images of Landsat series from 2002 to 2021 were selected. Threshold segmentation was employed to extract the coastline from these images. Subsequently, tidal level correction was applied to rectify the instantaneous water edge in the binary image of the target coastal area based on tidal channels, resulting in the acquisition of the target coastline. Finally, the obtained target coastline from different time periods were inputted into the Digital Shoreline Analysis System (DSAS). DSAS can be used to assess coastline changes using the end point change rate (EPR) and linear regression change rate (LRR). The research findings reveal that the average siltation rate of various sections along the Yancheng coastline is 105.62 m/y, with the maximum siltation length measuring 12,048 m, located in the Tiaozini reclamation area. Conversely, the maximum erosion length is 1820 m, situated near the mouth of the Shuangyang River. Taking the Sheyang River mouth as the boundary, the northern coastline of the river mouth experiences predominantly erosion, while the southern coastline is primarily affected by sedimentation. Moreover, the rate of coastline change gradually increases from north to south. The transformation of artificial coastline is the outcome of a combination of natural and human factors. Agricultural reclamation, port construction, and coastal protection engineering are identified as the main reasons for the artificial and seaward advancement of coastline. This study provides a foundation for the construction and protection of Yancheng’s coastal zone and offshore engineering. It holds significant practical implications for urban planning and development.