Characteristics and Driving Mechanisms of Terrain Evolution in the North Passage of the Yangtze River Estuary from 1997 to 2019
The estuarine sandbar is located at the junction of rivers and oceans,characterized by weak dynamics,easy sedimentation,and shallow water depth.Opening up sandbars and constructing deep-water channels have always been a challenge in oceanography and engineering.Currently,deep-water channel engineering has profoundly changed the evolutionary pattern of sandbar channels.This article collects underwater terrain data from 1997,2002.2007 and 2019 to analyze the characteristics of terrain evolution before and after the construction of the North Passage Phase Ⅲ waterway project.It also analyzes the driving effects of terrain evolution in the North Passage by combining factors such as waterway engineering construction,human dredging,and external environmental changes.The results show that after the construction of deep-water waterways,the North Passage of the Yangtze River Estuary mainly exhibits the characteristics of channel topography evolution,such as channel erosion,beach deposition,and sedimentation;In space,the upper section of the North Passage is mainly silted by the north mudflat and eroded by the south channel,while the lower section is mainly silted by the south mudflat and eroded by the North Passage.The construction of guide embankments and spur dikes is the main factor causing channel erosion and sedimentation,and the changes in the rising and falling tide paths caused by Coriolis forces also increase the differential evolution of the upper and lower sections of the channel;The construction of deep-water waterways was the main driving factor for sedimentation in the North Passage from 1997 to 2007,while human dredging was the main influencing factor for erosion in the North Passage from 2007 to 2019;Although human activities have become the main cause of the evolution of the North Passage,changes in the surrounding environment,such as reduced sediment from the basin and rising sea levels,have also intensified recent erosion in the North Passage.
north passage of the Yangtze River Estuarydeep water waterwayshuman activitiesdriving effect
NETL
NSTL
万方数据
