黄河河口拦门沙发育动态

河口拦门沙发育主要取决于河口边界、径流、海洋动力、海面增减水以及河口疏浚等环境要素的相互作用。拦门沙在口门附近呈扇状分布隆起的沙坝,沉积结构为紧密的“铁板沙”.1984-1987年拦门沙自然发育时期,拦门沙长度为7km以上,年平均推进速度1.30km,沙顶高程为-0.1-0.5m;1988-1992年拦门沙人为疏浚发育时期,通过河口疏浚后,拦门沙增长有所减缓,其长度减为4-6km,年平均推进速度降为1.26km,沙顶平均高程下降到-0.7m,相应地减轻了河口地区的防洪压力。

DYNAMIC STATE OF THE BAR AT THE YELLOW RIVER MOUTH

The development of the mouth bar is Influenced by the boundary conditions of the river mouth,runoff,oceanic power,sea level change and channel dredging. The mouth bar,taking shape of fan,is composed by closely compacted sands.In 1984 1987 in natural situation,the Yellow River mouth bar was over 7km in length,with its top at an elevation of-0.1m--0.5m,and it moved seaward at a speed of 1.30km/a.In 1988 1992,the mouth bar was dredged,its length decreased to 4 6km, and its top was at an elevation of 0. 6m at an average,and the rate Of Progression was 1.26km/a; therefore the Pressure Of laborious flood control in the reaches of the river mouth was alleviated.