Estuary shifting and the impacts on coastline changes in the yellow river delta

The Yellow River Delta is a relatively new and dynamic land covered an area about 5400km 2 . The estuary channel has shifted significantly due to high sediment availability and thus resulting riverbed aggradations. The shifting of the estuary always follows a natural and cyclic process in four steps, including, riverbed aggradations, river channel migration, channel meandering, and course change at the end. The shifting scope of the estuary covered the whole delta area. After course changing, a large sand mouth is formed projecting into the sea, and a small bay is created between two of the river mouths. The coastline of the Yellow River delta is a tortuous line that connects six large sand mouths, and the total length is about 300km. The coastline of the delta is dynamic in two areas, one is in coastline extension or land-making at the present river mouth due to a large quantity of sediment, the other is coastline erosion near abandoned river mouths due to lack of sediment replenishment, unstable deposited soil and high tidal erosion. The main objective of this paper is to elaborate the process of estuary shifting and coastline change, present an analysis of land progradation and erosion rate, and the relationship between total sediment quantity and coastline change.