Erosion factors and prevention engineering on Huangcuo beach of Xiamen Island

黄厝沙滩位于厦门岛的东南岸,长4.2km,走向为NE—SW.东距小金门岛4.6km.南距大担、二担等小岛4km.1956年至2001年的45a间,在优势的NE向风和浪的作用下,沙滩平均每年以约2m的速度后退.近20a来,由于人工挖砂和海岸工程不当等原因,黄厝沙滩受到更严重的破坏.在近年沿岸道路和绿化带的施工中,人为地把原来大于30°坡度的天然侵蚀陡坎削成小于10°并与沙滩连接成一个坡面的缓坡.强台风袭来时,出现了多处沙滩砂不受阻挡地冲越上马路,冲越高程超过黄零8.5~9.0m.在宽40多米的环岛路上积砂厚达8~10cm!为了有效地保护黄厝沙滩,防止海岸线继续后退,应当采取挡沙坝或"离岸坝"工程以阻止纵向泥沙搬运,同时在可能出现横向砂冲越上岸的岸段和侵蚀后退严重的岸段修建护岸和挡浪墙工程以阻挡台风时大量海滩砂向陆地冲越.Huangcuo beach is 4.2km long in the direction of NE-SW,along the southeast coast of Xiamen Island.It is 4.6km to Xiao Jinmen Islet in the east and 4km to Dadan Islet in the south.The beach has been eroded and the coast-line retreated in about 2m/a from 1956 to 2001 due to the predominant wind and wave in direction of NE.The beach erosion became acute in last 20 years due to sand explorations and unsuitable coastal engineering.The road construction along the coast had caused the slope of the bank change from >30°down to