中国闽粤沿海现代海平面上升的海岸地貌响应

COASTAL GEOMORPHIC RESPONSE TO THE PRESENT-DAY SEA LEVEL RISE IN FUJIAN AND GUANGDONG

根据广东珠海淇澳岛东澳湾、高栏岛飞沙、福建晋江深沪湾等地海岸地貌与海滩沉积特征的野外观察与实验分析 ,确认闽粤沿海存在明显的海岸侵蚀后退现象 ,具体表现为 :海岸线向陆迁移 ,海湾内早期陆相冲积物遭受波浪侵蚀 ,岬角岸段早期海蚀龛被现代海滩沉积物掩埋 ,海岸沙丘物源区被海水吞蚀 ,古海岸沙丘遭受波浪侵蚀并被现代海滩沉积物覆盖 ,海滩沉积物呈现粗化和角砾化特征等 .这些地貌与沉积现象是海岸地貌对海平面上升的响应 ,它们的存在说明海平面上升是引起研究区海岸侵蚀后退的主要原因 。

Based on the field observations and laboratory analyses of coastal geomorphic and beach deposit characteristics of Dong'ao bay, Qi'ao island and Feisha beach Gaolan island, Zhuhai, Guangdong province and Shenhu bay, Jinjiang, Fujian province, it is confirmed that there are distinct coastal erosion and retreat phenomena on Fujian and Guangdong coasts. The coastal erosion and retreat are identified as follows: 1) inland moving shoreline; 2) wave eroded earlier terrestrial deposits at bayhead; 3) beach buried earlier notch; 4) source region losing of coastal dunes; 5) wave eroded and covered ancient coastal dunes; 6) coarser and more angular grains of beach deposits. These phenomena are geomorphic response to the sea level rise. Their existence indicates recent sea level rise and shows that the main reason of coastal erosion in study areas is sea level rise.