黄河下游每年约有4亿吨泥沙沉积在河道里,其中有2.8亿吨粒径大于0.05mm的粗泥沙,这部分泥沙是威胁黄河下游的根源之一,研究这部分泥沙来源区的范围、数量和产生的地层,对治理黄土高原和减少下游河道淤积有着重要的意义。 About 400 million tons of sediment are deposited in the lower reaches of the Yellow River every year, of which 280 million tons are coarse sediments larger than 0.05 mm in diameter. This part of sediment is one of the root causes that threaten the lower reaches of the Yellow River. The range, amount and formation of the strata are of great significance to the governance of the Loess Plateau and the reduction of siltation in the lower reaches of the Loess Plateau.