The Jiuduan shoal in the Changjiang estuary has been growing in size since the 1950s due to sediment accumulation caused by water flow. Changes in water and sediment conditions have led to erosion at the head of the shoal and accumulation at the tail. Recent human interventions have stabilized the northern part of the shoal, but the southern part continues to change. To maintain safe navigation channels, further human actions are needed to manage the impact on the shoal.