黄河三角洲海岸强侵蚀机理及治理对策

Mechanism of heavy coastal erosion on Yellow River delta and its countermeasures

黄河三角洲从挑河湾到孤东临海堤北端是黄河刁口河和神仙沟行水期间发育形成的年轻海岸,为强蚀型岸段。经初步计算,1976～1988年,每公里年均泥沙侵蚀率为320万t,现已建有桩西海堤和孤东海堤进行防护,但侵蚀仍在继续。本文分析了侵蚀的主要原因:一是流路停行初期,波状岸滩地形在涨落潮流往复作用下侵蚀;二是波浪能对底沙起作用的水深区位于强潮流区,波、流结合加剧了侵蚀作用。为此,单一的海岸防护工程,不能消除该岸段的泥沙流失,应同时通过调沙措施使其达到动态稳定。建议采用"二级分汊、多汊并存、人工控制、按需排放"的治理对策,避免海岸侵蚀,同时消除陆域洪灾。

Heavy erosion takes place at the coast of the Yellow River delta from Tiaohe Bay to the north end of Gudong Dyke. The sediment erosion rate is about 3.2×10~6t/a. The major causes of erosion are the cyclic action of tidal current and the wave action. The combination of tidal flow with wave action aggravates the erosion. Both coastal engineering and controlling of sediment transportation are important measures to ensure the dynamic stability of the coast. It is recommended that to maintain the multi-bifurcation of the river mouth and control the river flow according to the requirement of deposition are reasonable countermeasures for avoiding the heavy erosion.