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一、概述崇明岛是由长江上、中游水土流失形成的冲积岛。长江每年从上、中游下泄近5亿t泥沙,由于受动力因素和海潮咸淡的顶托,楔状相交,絮凝沉积,由星星沙洲,逐步发育成拥有1136km~2的我国第三大岛。长江之水造就了崇明岛,然而却又在不断地侵蚀着崇明本岛之土。过去崇明岛沧桑多变,涨坍不定,县址曾五迁六建,就是水土流失的明显写照。如今在党和政府的重视下崇明岛四周已兴建了近130km的环岛大堤、180道丁坝和77km护坎工程,基本控制了
I. Overview Chongming Island is an alluvial island formed by the soil erosion in the upper and middle reaches of the Yangtze River. The Yangtze River discharges about 500 million tons of sediment from the upper and middle reaches each year. Due to the dynamic factors and the brackish top of the sea, the wedge intersects and the flocculation sediments are gradually developed into the third largest island in China with 1136 km2. The water of the Yangtze River has created Chongming Island, yet it continues to erode the soil of Chongming Island. Chongming Island in the past vicissitudes of change, rising uncertainties, the county has moved five times to build five, that is an obvious portrait of soil erosion. Nowadays, about 130km of the island embankment, 180 Dingba and 77km ridge projects have been built around Chongming Island under the control of the party and the government.