Climate and human battle for dominance over the Yellow River's sediment discharge: From the Mid-Holocene to the Anthropocene

Understanding the flux of riverine sediment is crucial not only to document the global terrestrial material budget but also to understand erosion patterns within the drainage basin under the impact of natural and anthropogenic forces. Here we reconstructed changes of sediment discharge in the Yellow River over the last 7000 years based on a large number of C-14 dates obtained from literature and discussed the impact of climate change and human activities from the mid-Holocene to the Anthropocene. From 7000 to about 3000 cal yr BP, the Yellow River's sediment discharge was lower than 0.09 gigatonnes per year (Gt/yr). Due to low population and limited ability to conquer nature, climatic conditions almost completely controlled the sediment discharge over this period. After 3000 cal yr BP, the sediment discharge increased gently to 0.23 Gt/yr at 1400 cal yr BP. Since then, the sediment discharge increased abruptly to 1.56 Gt/yr in 1855 CE and subsequently remained at a fairly high level of 1.31 Gt/yr with fluctuations for nearly a century. Human activities gradually enhanced the increasing trend of sediment discharge and began to affect the environment at a scale comparable with powerful natural forcing due to population growth and technique innovation. Since the late 1950s, the terrestrial sediment from the Yellow River to the sea has experienced a cliff-like drop, which appears to be reverting to the pristine levels of the middle Holocene. With the explosive growth of the population, technological innovation and economic development, human activities in the drainage basin intensified continuously and greatly regulated the water and land resources.