Abstract:Taking Shanghai coast zone as the study area and using the 1985-2015 landsat images as the data source, a new method for coastline extraction is proposed. By incorporating the processes such as object-oriented image segmentation, threshold selecting, edge detection and tide correction, the coastline within the study area over seven years is extracted frame by frame. The change rule of the coastline in Shanghai in recent thirty years is analyzed. The result shows that the change of the coastline in Shanghai is affected by both natural and human factors. The total change of the coastline in Shanghai appears as coastline outward extension and siltation. The total length of the coastline exhibits the trend of rising. The coastline increases from 176.54 km in 1985 to 189.77 km in 2015. The length of the new added coastline is 13.23 km. This research result reveals the developing process of Shanghai coast zone. It lays a basis for the further extraction and analysis of the change rule of land use in Shanghai coast zone.