Characteristics of Mudflow Distribution and Evolution of Mudflow Fan in Erlian Village

Debris flow in the upper Yellow River is very developed and is generally characterized by wide distribution with large numbers and a high frequency of occurrence. This paper analyses the distribution characteristics, material composition, and formation causes of the Erlian debris flow fan in the eastern part of the Guide Basin and discusses the relationship between debris flow fan and river evolution. Results show that: (1) At least 66 debris flow gullies and 20 large debris flow accumulation fans have been developed on both sides of the Yellow River in the eastern Guide Basin. (2) In the Erlian Village area, the Yellow River channel has experienced the accumulation, erosion, destruction, and accumulation process of debris flow fans in 16 kaB.P., 16 ka B.P.–8 ka B.P., and 8 kaB.P., respectively, the late-accumulation fan has been continuously extruding the Yellow River channel since 8 kaB.P., and the Yellow River channel has been shifted to the south by at least 1.25 km during the period of 8 ka. (3) Five accumulation periods for the Late Mudslide Fan were identified by classifying the 16 kaB.P. and 8 kaB.P. early and late mudslide fans. This study can provide theoretical and technical support for preventing debris flow disasters in the upper reaches of the Yellow River and has certain reference and reference values.