北仑河口北冲西淤形成与环境因素的影响分析

Analysis on environmental factors affecting the formation of north scouring and west siltation in Beilun estuary

研究发现,北仑河口的泥沙主要来源于二个方面,一是北仑河及其周边小河径流挟沙;二是潮流和波浪联合作用掀沙。径流挟沙比潮流和波浪掀沙大。夏季汛期,由径流带入的泥沙大部分在航道附近落淤,形成河口大片浅滩。自20世纪80年代以来,随着城镇化建设加快,沿河用水逐年增多,河流输沙显著减少。而受潮流影响的主航道,偏向中国一侧,在上游供沙少的情况下,不断加大河底冲刷,造成河口北冲西淤的发展态势。

The research shows that the sediment of Beiun estuary comes mainly from two aspects： carried by Beilun river and its surrounding small rivers, lifted by current and wave combined effect. Sediment produced by the former is more than that by the latter. In the flood season of summer, most sediment which is carried by runoff silts near the waterway,and forms large shoals in estuary. Since the 1980s, with the urbanization accelerating, water use has increased year by year along the river, and river sediment transport has significantly reduced. The main channel which is affected by current has leaned to Chinese side, and the riverbed erosion has been increased continually in the case of the upstream sand supply reduction. As a result, the trend of north scouring and west siltation in the estuary has been created.