Analysis of spatiotemporal dynamic changes of the north Jiangsu coastline in the past 40 years

Coastline plays an important role in indicating sea-level rise, coastal erosion, harbor accretion, wetland ecological resources and coastal environment. Using remote sensing (RS) and geographic information system (GIS) technology to obtain the coastline data of the northern Jiangsu coast in the period of 1978－2018, the coastline length change, coastline change rate and coastline type change were analyzed, and the estuaries were taken as the boundary point to analyze the coastline change characteristics. The results show that: (1) In the past 40 years, the total length of coastline in the study area has a decreasing trend, and the change of coastline type is more obvious. The artificial coastline and the natural coastline have a trend of increasing and decreasing with time, respectively. (2) During the period of 1978－2018, the rate of coastline advancing to sea is much higher than coastline advancing to land. (3) From 1978 to 1988, the coastline between Sheyang estuary and Xinyang port has the most obvious propulsion speed, which is mainly pushed to the sea in the way of accretion, and the average end point rate (EPR) of the coastline is 281.4 m/a; From 1988 to 1998, the coastline between Xinyang port and Doulong port has the most obvious propulsion speed, which is mainly pushed to the sea in the way of accretion with the average EPR is 535.5 m/a; During 1998-2008, the coastline accretion rate between Doulong port and Dafeng port is the most obvious, mainly by artificial reclamation to the sea with an average EPR of 502.1 m/a; During 2008—2018, the coastline accretion rate between Liangduo estuary and Fangtang estuary is the most obvious, mainly by artificial reclamation to the sea area with an average EPR of 347.7 m/a.