现代黄河三角洲的海岸侵蚀及其环境影响

Coastal erosion and its environmental effect in the Modern Yellow River Delta

现代黄河三角洲属粉砂淤泥质海岸,受陆域黄河水沙量变化与海洋水动力条件的共同作用,海岸侵蚀现象严重,且具有明显的时空变化特征。1976年黄河改走清水沟流路后,刁口河故道入海口岸线开始蚀退,初期侵蚀速度很快,近10 a来蚀退明显减缓;同时行水河口发生淤积。1990年后,尤其是近年来,泥沙供应大量减少,海陆作用力对比变化,除行水河口泥沙在有限范围内堆积造陆外,沿岸大范围内普遍表现为蚀退。岸线蚀退的同时,岸滩下蚀也很明显。在海岸侵蚀作用下,作为中国典型滨海河口湿地的现代黄河三角洲环境不断退化。应系统地认识海岸侵蚀灾害及其复杂性,建立综合管理体系,缓解侵蚀,改善滨海湿地环境。

The coast of Modem Yellow River Delta belongs to silt muddy coast, and it is impacted together by the volume of water and sand of Yellow River and marine coastal hydropower, its erosion is serious and the change has obvious temporal and spatial characteristic. In 1976, the Yellow River changed its flow along Qingshuigou, the coast of Diaokou outfall, which is the old course of Yellow River, began to erode. At the early years, the velocity of erosion is fast, recent ten years, the velocity is slower obviously. To the contrary, in the current outfall area occurs silting up. Since 1990s, especially recent years, the sediment discharge in the Yellow River was becoming less and less, so the area of siltation is limited around of current course, and the erosion occurs at large area in coast. As a typical coastal wetland of China, the environment of Modern Yellow River Delta is degraded because of the erosion. We should systematically and roundly research the complexity of coastal erosion in order to establish an integrated management system to mitigate it and improve the environment of coastal wetland.