近40 年苏北海岸线时空动态变迁分析

海岸线对海平面上升、海岸侵蚀、港湾淤积、湿地生态资源和近海海域环境等具有重要指示作用。利用遥感（remote sensing, RS）和地理信息系统（geographic information system, GIS）技术获取苏北海岸在1978年至2018年5期海岸线数据，对海岸线长度变化、岸线速率变化以及岸线类型转变进行分析，并以河口为分界点对岸线变迁特征分段分析。结果表明:（1）40 年间研究区岸线总长度大致呈现递减趋势，岸线类型变化较为明显，随时间推移人工岸线和自然岸线分别表现为增长和削弱的趋势。（2）研究区在1978年至2018年，海岸线向海域推进速率远大于海岸线向陆域推进速率。（3）1978年至1988年，射阳河口至新阳港口之间的海岸线推进速率最为明显，主要以自然淤长的方式向海域推进，岸线平均端点速率（end point rate, EPR）为281.4 m/a；在1988至1998年，新阳港口到斗龙港口之间岸线推进速率最为明显，主要以自然淤长方式向海域推进，平均EPR为535.5 m/a；在1998年至2008年，斗龙港口到大丰港口之间岸线推进速率最为明显，主要以人工围垦方式向海域推进，平均EPR为502.1 m/a；在2008年至2018年，梁垛河口到方塘河口之间岸线推进速率最为明显，主要以人工围垦方式向海域推进，平均EPR为347.7 m/a。

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.