利用潮汐治理河口拦门沙的探讨

Research on Harnessing the Sediment Silt at the River Mouth Through Tides

黄河是弱潮河口，潮差小于2m，但是黄河三角洲沿岸存在M2分潮“无潮点”，是一个高流速辐散流场，最大流速120cm／s以上，影响着沿岸潮流场特性。同时，黄河河口段河道稳定，沙嘴突出后，河口外流场显著增强，加强河口治理，可维持沿岸强潮流带，减缓河口淤积延伸。根据黄河口淤积延伸快、有广阔潮滩的特点，提出了在河口沙嘴上设置活动式橡皮坝的设想，并对橡皮坝增大纳潮量作了初步估算，冲刷降低拦门沙效果明显，尤其是枯水季节。

The Yellow River is characterized of weak tides with tide difference less than 2 m. However, thereare M2 'non-tide points' of tide branches along the coast of the Yellow River delta, which is a radialspeed field with high velocity and the maximum flow velocity can be above 120 cm/s that influence thecharacteristics of the tide flow along the coast. Besides, the reaches in the Yellow River mouth are stable, the projecting sand spit will strengthen the flow field outside the river mouth, therefore, sediment siltat the river m0uth can be slowed and the strong tide flow along the coast can be kept through enhancinghamessing the river mouth. According to the characteristics of wide tide beach and quick sedimentation atthe Yellow River mouth, it is suggested in the paper to construct movable rubber dams on sand spits atthe river mouth, and the tide volume increased by the dams is calculated, which shows evident effects onscouring sedimentation at the river mouth especially in dry seasons.