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利用长江口人类活动强干扰下的海图水深数据及河槽表层沉积物资料,探讨近期长江河口主槽冲淤变化与沉积物分布特征,研究结果表明,在流域来水量变化不明显,来沙量锐减的情况下,长江河口段中上游主槽整体上处于微冲刷环境。而又受深水航道治理工程的影响,局部河段主槽出现淤积,沉积物粒径也发生相应的变化。其中,南支下段宝山水道总体上受到冲刷,沉积物枯季变细,洪季变粗;南槽航道上段、北港航道和横沙通道均受到冲刷,沉积物均逐渐变粗;南港航道、与北槽过渡河段的圆圆沙航槽和北槽航道主槽淤积,沉积物均逐渐变细,且三者的淤积均由航道回淤造成,南港航道回淤的沉积物粒径最粗(0.12mm左右),圆圆沙次之(0.07mm左右),北槽最小(0.02mm左右)。
Using the charts of seafloor water depth data and surface sediment data of the Yangtze River estuary due to strong human activities, this paper discusses the recent scouring and silting changes and sediment distribution characteristics of the main channel of the Yangtze River estuary. The results show that there is no obvious change in the water inflow, In case of sharp decrease, the middle and upper main channel of the Yangtze River estuary section is in a micro-scour environment as a whole. Affected by the project of deepwater channel regulation, however, the main channel of partial river siltation occurs and the sediment particle size also changes correspondingly. Among them, the Baoshan waterway in the lower section of the South Branch was generally washed away, and the sediment became thinner in the dry season and coarser in the flood season. The upper section of the South Passage, the North Harbor channel and the Hengsha channel were washed away with thick sediments. The Nangang channel, The sediment of the round sand channel and the main channel of the north channel channel in the transitional channel of the North Channel is silting, and the siltation of the three is caused by siltation of the channel. The sediment particle size of the siltation in the South Channel is the coarsest 0.12mm or so), round sand times (about 0.07mm), the smallest North Channel (about 0.02mm).