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基于长江河口1997年以来数字地形图和近期水文泥沙实测资料,分析研究了近期长江河口大量人工整治工程和流域水库工程建造影响下的河口河道自动调整过程。结果表明:1997-2013年河口段中上游河道微冲刷、拦门沙滩顶仍保持淤积外移、口门外侧近海域冲刷的态势略有增强,而其影响原因与历史时期的自然因素影响为主略有差异,近期人类高强度活动的影响贡献率增大。首先,南支至南港和北港中上游河段河床普遍发生冲刷,河床沙活动较活跃,床面微地貌沙波发育更明显,而口门外侧海域地形略有冲刷蚀退,这些变化与流域来沙锐减有直接关系;北支、北港口门、南槽和北槽河道拦门沙河段呈淤积,尤其北槽主航道的拦门沙河段6m水深浚深为12.5m后回淤量很大,这些与拦门沙河道动力结构环境、河口和海域再悬浮泥沙补给有关;局部河段出现强冲和强淤现象,与近期河口工程建造有关。所以,长江河口近期正处在对自然因素变化和人类活动增强的自我缓慢地自动调整和适应过程之中。
Based on the digital topographic maps of the Yangtze River estuary since 1997 and the recent hydrological and sediment measurements, the recent automatic adjustment of estuaries under the influence of a large number of artificial remediation projects in the Yangtze River estuary and the construction of reservoir reservoirs has been analyzed. The results show that in the middle and upper reaches of the estuary between 1997 and 2013, micro-scouring and sediment deposition in the middle and upper reaches of the estuary kept silting and migrating, while the scouring near the outer mouth of the mouth increased slightly, while the influence was mainly due to natural factors in the historical period A slight difference, the recent contribution of human high-intensity activities contribute to the increase. First of all, the erosion of the bed of the middle reaches of Nanjiazui to Nangang and the middle reaches of North Port generally occurred. The riverbed sand activity was more active. The bed topography of sandstone developed more obviously. However, Sharui reduction has a direct relationship; North Branch, North Port Gate, South Channel and North Channel barren Shahe river sedimentation, especially in the main channel of the North Channel Shahe 6m deep water depth of 12.5m deep siltation after a large amount , Which are related to the power structure environment of estuary sand channel, resupply sediment supply in estuaries and sea areas; strong red and strong siltation occurred in some river sections, which is related to the recent estuary construction. As a result, the estuary of the Yangtze River is in the process of self-adjustment and adaptation to self-retardation that has recently been accompanied by changes in natural factors and enhanced human activities.