The self-regulation process and its mechanism of channels' bed changes in the Changjiang(Yangtze) Estuary in China

作     者：ZHANG Xiaohe LI Jiufa ZHU Wenwu CHENG Heqin CHEN Wei 

作者机构：State Key Laboratory of Estuarine and Coastal Research East China Normal University Institute for Marine and Atmospheric Research Utrecht Utrecht University 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2015年第34卷第7期

页      面：123-130页

核心收录：

学科分类：0710[理学-生物学] 0908[农学-水产] 0707[理学-海洋科学] 08[工学] 081502[工学-水力学及河流动力学] 0815[工学-水利工程] 

基　　金：The National Natural Science Foundation of China under contract Nos 51479074 and 41340044 the Special Key Program of the Ministry of Science and Technology of China under contract No.2013FY112000 

主　　题：Changjiang Estuary bathymetric changes self-regulation human activities tidal current sediment transport 

摘      要：Recent bathymetric changes in the Changjiang Estuary under the influence of artificial regulation engineerings and basin reservoirs have been analyzed based on the maritime charts since 1997 and recent fieldworks. The results indicate a slight erosion of the channels in the upper and middle estuary, continuing deposition and seaward move of the mouth bar crest and intensifying erosion at the nearshore seabed. It is noteworthy that the morphological evolution caused by intensive human activities dominates over the changes from nature process. First, the riverbes are eroded overall in the South Branch （SB）, the South Channel （SC） and the upper and middle reaches of the North Channel （NC）. The nearshore seabed outside the river mouth is being eroded slightly, which is attributed to the declining sediment supply from the Changjiang Basin due to the construction of the Three Gorges Dam upstream. The sediment above the seabed is very active and coarsened, meanwhile, sand waves are becoming more distinct. Second, a deposition occurs in the North Brach （NB）, the mouth of the NC, the mouth bars of the North Passage （NP） and the South Passage （SP） and especially the main channel of the NP, where it shows a massive siltation after the deep waterway project. The reasons for the recent changes are not only the dynamic structure in estuarine mouth bars, but also the supply of sediment resuspension in a local and offshore area. Meanwhile, the severe erosion and siltation in some reaches is related to the construction of estuarine engineerings. It is indicated that the Changjiang Estuary is gradually self-adjusted and adapting to the varying natural factors and intensive human activities. The study on the mechanism of self-regulation of the recent bathymetric changes in the Changjiang Estuary has important and practical significance.