Land accretion of the Yellow River Delta as influenced by drainage basin factors

摘要

The land accretion processes of the Yellow River delta, with its quantities of sediment transport, are dominated by drainage basin factors. Since the tidal and the sea wave processes are weak, the delta provides an ideal site to study the response of land accretion to the changing climate and human activities. Firstly, by using sea charts and remote sensing images, the annual land accretion area has been identified and is related to annual precipitation and human activities in the drainage basin. It is found that the rate of land accretion of the delta is positively correlated with precipitation, but negatively correlated with the areas of erosion control measures and with the quantity of water diversion. Secondly, a multiple regression equation has been established between the rate of land accretion of the delta and the influencing factors: the area of terrace land building and tree- and grass-planting, the area of the land created by the sediment trapped by check dams, the annual precipitation and the annual quantity of water diversion. The regression indicates that the changing precipitation contributes most to the land accretion rate of the delta, the contribution made by erosion control measures ranks the second, and the contribution made by water division the third.