A GIS-Supported Study of the Influence on the North Passage Bar after Executing Yangtze Estuary Deepwater Channel Regulation Phase I & II Project

A number of charts of the Yangtze Estuary in the period of 1995-2003 are digitized. Supported by GIS tools (ArcInfo8.3),digital elevation models (DEM) of the Yangtze Estuary are then established with the Kriging girding method. Based on the DEM, underwater terrain variations of North Passage of the Yangtze Estuary are modeled quantitatively through various representations, including cross-sections, thalweg sections, and overall terrain variations. It is in an attempt to quantify the scouring and silting sediment distribution and its variations in the mouth bar area of North Passage prior and after the First Phase of Yangtze Estuary Deepwater Channel Regulation Project. The results show that the 1st phase regulation project has increased the velocity of flow and reduced the sedimentation of the channel, and it has also resulted in an 8-10 m microbending trough. The 2nd-phase regulation project has retained the form of 1st-phase one with less modification in the profile of the channel.