253 / 2024-02-28 16:51:11

The impact of natural and anthropogenic factors on erosion in the northeastern Loess Plateau, China, during the past 10,000 years

Loess Plateau,Yongding River,Erosion,Holocene,Anthropogenic stress

      The Loess Plateau in China is the birthplace of ancient Chinese cultures, and one of the most significantly eroded areas in the world due to its geology and anthropogenic history. However, our understanding of variations in erosion of the Loess Plateau over the past 10,000 years, and how these have been influenced by natural and anthropogenic factors, remains incomplete. The Yongding River is the river transporting the second largest quantity of sediment through the Loess Plateau, after the Yellow River. Present study uses data from both hydrological station and detrital zircon in paleo flood deposits to reconstruct the history of loess erosion in the Yongding River catchment over the past ~10 ka, which enables the influence of natural and human factors to be investigated. Before 2.9 ka, sediment transport flux increased slowly and human activities were minor, but subsequently began to increase at a faster rate. Destruction of forests and grasslands, together with changes in agricultural practices, likely played significant roles, especially after the Yuan Dynasty established the capital in Beijing (1267 AD). Since this time, anthropogenic activities such as urban construction and agricultural development have increased sediment yield in the Yongding River catchment dramatically, with this increase continuing until the first half of the 20^th century, when the sediment flux was c. 4.3 times greater than the background value before 2.9 ka. After the 1950s, due to the influence of reservoir construction and reforestation policies, sediment transport in the Yongding River catchment decreased sharply. Combining the gauged data and sedimentary archives, this study extended the temporal scale of the sediment transport data, thus contributes to a better understanding of the temporal patterns of erosion of the Loess Plateau due to natural processes and anthropogenic stresses, and which can inform and benefit future river basin management.