Evolution history and trend of the modern Huanghe River Delta

摘要

The evolvement history of modern Huanghe River Delta tidal flat,coastline and underwater terrain were studied based on the analysis of remote sensing images and water depth data.Based on the analysis of seafloor terrain evolution on different historical stages,a formula simulating the erosion and deposition evolvement model of subaqueous Huanghe River Delta slope was proposed,and the evolvement trend of the subaqueous delta terrain was predicted.The result shows that the equilibrium transition zone is near the water depth of 12 m with seabed erosion in shallower water and accumulation in deeper water during the first 150 a after the river channel was deserted.In the meantime,the underwater slope became gentler and the coastal erosion rate became slow gradually.Then,the subaqueous delta slope changed to up concave from upper convex,and the shape of subaqueous delta disappeared.The coast type changed to silt-mud coast about 100-150 a after the river course was deserted.The erosion depth in the foot of the seawall is calculated based on the formula.