Shoreline Change of the Northern Yellow River (Huanghe) Delta after the Latest Deltaic Course Shift in 1976 and Its Influence Factors

222 high-quality Landsat satellite images were used in this study to extract the instantaneous shoreline positions on 22 sections of the northern Yellow River delta. Based on the instantaneous water line position data, a new statistical method for studying annual shoreline change was proposed. The annual shoreline movement of the northern Yellow River delta after the latest deltaic course shift in 1976 was obtained. The results showed that the shoreline on northern Yellow River delta was mostly undergoing a retreat back process since 1976 due to the river course shift, relative sea level change, regional marine hydrodynamic forces and the local engineering constructions. The influence of the Yellow River deltaic course shift in 1976 on the shoreline change mainly occurred in the first 20 years in 1976-1996 after the course shift, and was mostly limited within 10 km range around the abandoned Diaokou river mouth. The coastal engineering constructions caused decrease of the erosion area by 61 km(2), or 31% of the total erosion area. Most of the northern Yellow River delta was relatively insensitive to the relative sea level change except for the coast around sections S10 and S11; The annual shoreline movement due to the relative sea level change along most of the coast was only 1-3% of the actual annual shoreline movement; the total erosion area due to the relative sea level change was 9 km(2), or 5% of the actual erosion area. The coast erosion in the northern Yellow River delta was mainly influenced by the regional marine hydrodynamic forces, which gradually increase from west to east, resulting in gradually eastward increase of annual shoreline movement and slope steepness of the coast.