The study analyzed the evolution of shoals around alluvial islands in the Changjiang estuary using GIS technology. By digitizing historical charts and creating digital elevation models, the researchers found that the shoals have been growing and moving seaward over the past 150 years. Approximately 1.948 billion tons of sediment have been deposited in the area, with an average annual deposition rate of 16.1 million tons. The natural evolution of the shoals is influenced by sediment from the Changjiang stream, but human activities like coastal engineering are increasingly impacting this process.