1973年以来射阳河口附近海岸蚀淤变化遥感分析

Remote sensing analysis of shoreline changes along the coast near the Sheyang River Estuary of Jiangsu Province since 1973

以射阳河口北部扁担港口和射阳河口南部斗龙港口之间的海岸作为研究区,基于1973,1987,2000和2013年四期Landsat影像提取了该岸段岸线,并进行了时空变化分析。结果表明,射阳河口以北的扁担港口—射阳河口岸段仍处于侵蚀状态,呈现侵蚀—淤积—缓慢侵蚀的变化格局,40 a间侵蚀面积为12.6 km^2,淤积面积为1.0 km^2;射阳河口以南的射阳河口—斗龙港口岸段处于淤积的态势,呈现淤积—快速淤积—缓慢淤积的格局,40 a间淤积的面积为223.1 km^2,仅在2000-2013年间该岸段北部出现了侵蚀。结论是虽然射阳河口以南岸段仍总体处于淤积的过程中,但是近年来江苏海岸的侵蚀范围已经扩展到了射阳河口以南,这证明了江苏海岸侵蚀岸段有进一步扩大的趋势。

The Sheyang River Estuary is the demarcation point of coastal changes of Jiangsu Province, recession in the north, accretion in the south, and the length of receding coastline is gradually increased. To investigate and monitor the evolution of shoreline near the Sheyang River Estuary area, the coast between the Biandan Harbor in the north of the estuary and the Doulong Harbor in the south of the estuary was selected as the study site, and the Landsat data obtained in 1973, 1987, 2000 and 2013 were used to extract the shorelines. Then the spatial-temporal changes of the coastal area were analyzed. The present study indicates that the coast area in the north of the estuary is in the state of erosion showing the pattern of erosion-accretion-slow erosion, with the coastal area decreasing 12.6 km^2 and increasing 1.0 km^2 in 40 years. While the coast in the south of the estuary is in aggradation, revealing the change pattern of accretion-fast accretion-slow accretion, with the coastal area increasing 223.1 km^2 in 40 years. The erosion has occurred since 2000 in the north of the Sheyang River Estuary southern coast.