Coastline change of the Yellow River estuary and its response to the sediment and runoff (1976–2005)

The dramatic decreases in runoff and sediment have great impacts on erosion–deposition variation in the Yellow River estuary. This study extracted mean high tide lines of the Yellow River estuary from MSS, TM and ETM+ data from 1976 to 2005, and explored relationships between the accretion–erosion of land and the runoff and sediment load of the Yellow River. The results showed that the general pattern of accretion–erosion of the entire estuary was divided into four stages: rapid accretion stage (1976–1986), accretion–erosion adjustment stage (1986–1996), slow erosion stage (1996–2003), and slow accretion stage (2003–present). For maintaining the annual balance of the entire estuary (1976–2005) and Q8 estuary (most recent course of the Qingshuigou estuary from 1996 to 2005), critical annual runoff and sediment load are 140.36 × 108 m3 year− 1 and 3.31 × 108 t year− 1, and 85.0 × 108 m3 year− 1 and 1.63 × 108 t year− 1, respectively. In the future decades, the Q8 estuary is likely to maintain its shape and area balance or have a little accretion, but the entire estuary could be in an eroding state.