Anthropogenic influences on changes in the sediment load of the Yellow River, China, during the Holocene

Abstract

Using data on formation of the Loess Plateau of central China, loess-palaeosol sequences, pollen analysis, historical geography, and long-term experimentation on rates of soil erosion, it is demonstrated that current serious erosion on the Loess Plateau is mainly due to human destruction of the natural vegetation and irrational land use. These two modifications greatly reduce soil-infiltration capacity and resistance of the soil to erosion. The increase of soil erosion began ca. 5000 BP at which time a hunting and pastoral life began to change gradually to a sedentary life centred around cultivation. Using the volume of Holocene loessic sediments on the continental shelf of the Bohai, Yellow, and East China Seas, it is estimated that the present sediment load of the lower Yellow River is at least three times greater than it was during the Holocene. Although human-induced soil erosion in the Loess Plateau began earlier, it was not until the Tang dynasty (about 1000 BP) that it began to increase rapidly. According to available information on projected and planned economic development and major conservancy works in the Yellow River basin over the next 25 years, it is predicted that sediment load of the lower Yellow River will be reduced by about 30-40% in the early twenty-first century.