The Xiaolangdi project has positively impacted the erosion-deposition variation in the Yellow River estuary by improving flow and sediment conditions. This led to a rapid change from erosion to deposition, with the spit extending at a rate of 0.9km per year. The project increased land-forming rates and extended the spit length significantly compared to natural conditions. To maintain this positive development, the project should regulate flow/sediment levels to specific values at the Lijin station.