海平面变化及其海岸响应

第四纪气温的大幅度冷暖变化，导致全球海平面的变化，引起陆架海侵扣海退。海岸上的各种地貌如海滩、沙坝、三角洲扣陆架沙脊等响应海平面升降而发生新的演化扣变异。东海陆架古岸线、围绕古岸线发育的陆架沙脊、陆架深切河谷扣河谷充填沉积以及冰后期海进型扣海退型沙坝的形成乖演化等沉积事件都是响应海平面升降的结果。近百年来特别是近30年全球海平面普遍上升，引起风暴潮的频度扣幅度的增大。近岸波能增强，越滩浪增多，导致海滩侵蚀，岸线后退。Bruun法则扣其他一些模型能够说明海滩随海平面上升而蚀退的规律，但在预测速率时仍存在很多问题。使用时应注意海平面变化的区域性、海滩发育的滞后性和海滩蚀退因素间的权重关系。

Sea Level Changes and Coastal Responses

Large amplitude changes of Quaternary atmospheric temperature induced the global sea level changes and continental shelf transgressions and regressions. And coastal geomorphic features such as beach, sandbar, delta, and continental shelf sand ridges, in response to the sea level changes, have had new evolutions and changes. In the East China Sea continental shelf, the ancient coastline, continental shelf sand ridges, downcutting river valleys and valley filling developed around the ancient coastline, and sedimentation events such as formations and evolutions of the post-glacial transgressive and regressive sand ridges all result from the responses to the sea level changes.During the past hundred years, especially during the last three decades, the sea level rose universally, which increased the frequency and amplitude of storm tides. The increase of offshore wave energy and over-beach waves caused the beach erosion and coastline retreat. Bruun principle and other models can explain the laws of beach retreat with the sea level rise, but they cannot correctly predict the speed rates. Please pay attention to the weight relations among regional characteristics of the sea level changes, the lagging-behind of the beach development and beach retreat due to erosion.