Abstract: To explore the dynamics of coastal erosion and prevention measures, Landsat series remote sensing data from 1985 to 2023 were used to create a time series of the intertidal zone in Yancheng Nature Reserve. Coastal accretion, erosion dynamics, and the changes in land use types across different years were analyzed. The results showed that: (1) Yancheng Nature Reserve shifted from an accretion-type coast (1988-2012) to an erosion-type coast (2012-2023). (2) Coastal accretion mainly showed a trend of gradual slowdown, reaching a peak rate of 521.8 hm²·a^-1 between 1997 and 2000. Coastal erosion showed a trend of first weakening and then strengthening, with the slowest erosion between 2003 and 2009 at a rate of 0.7 hm²·a^-1. (3) The area of wetlands affected by human activities and the area of Spartina alterniflora wetlands increased gradually at mean annual rates of 501.4 and 150.2 hm²·a^-1, respectively. (4) In terms of coastal accretion, S. alterniflora communities and areas affected by human activities accounted for 69.7% and 13.0% of the total accretion area, respectively. In comparison, S. alterniflora communities and areas affected by human activities accounted for 34.4% and 22.7% of the total erosion area, respectively. S. alterniflora played a significant role in promoting accretion and protecting beach in Yancheng Nature Reserve. Efforts should be made to strengthen early warning mechanisms and explore optimal measures to combat coastal erosion in Yancheng.

Key words: coastal erosion, ecological restoration, Yancheng wetland, Spartina alterniflora