Sediment Input from the Norfolk Cliffs, Eastern England - A Century of Coast Protection and Its Effect
Sediment Input from the Norfolk Cliffs, Eastern England - A Century of Coast Protection and Its Effect
复制标题
英格兰东部诺福克悬崖的沉积物输入——一个世纪的海岸保护及其影响
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
K. Clayton
中科院分区：
文献类型：
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作者：
K. Clayton
诺福克东北部 33 公里的悬崖平均高 25 m，在自然条件下的侵蚀为海滩系统提供了超过 5 x 10 5 m 3 - l 的沉积物，其中约三分之二是沙子和砾石。这为下流超过 60 公里的海滩提供了水源。如今，70% 的悬崖受到保护，沉积物供应量已减少至自然水平的 70-75%。减少的程度低于防御工事设计者的预期，但其中大部分是木制护岸，前面有可渗透的防波堤，这只能成功地将撤退率减少到其自然价值的三分之二左右。北部海岸与冲刷排列且侵蚀率较低的北部海岸与沿海漂移率较高的漂流排列海岸之间存在显着差异，后者侵蚀率较高且防御效果较差。
The 33 km of cliffs in northeastern Norfolk, average 25 m high and under natural conditions erosion supplies well over 5 x 10 5 m 3 yr - l of sediment to the beach system, of which about two-thirds is sand and gravel. This provides a feed to beaches for a distance of over 60 km downdrift. Today 70%, of the cliffs are defended, and the sediment supply has been reduced to 70-75% of its natural level. The reduction is less than was intended by the designers of the defences, but most of these are wooden revetments fronted by permeable groynes, which only succeed in reducing the rate of retreat to about two-thirds of its natural value. Considerable differences are found between the northern coast which is swash-aligned and has low rates of erosion, and the drift-aligned coast with its high rates of littoral drift where rates of erosion are high and defences are less effective.