Abstract:
[Objective] The Haihe River Basin, located in the northern part of the North China Plain, serves as a transitional zone between northern and southern climates in China. It is a sensitive area for hydroclimatic changes and frequently experiences flood disasters. Reconstructing the regional paleoflood history is crucial for assessing the impacts of future extreme flood disasters. However, research on the occurrence patterns and driving mechanisms of paleoflood events in this basin remains insufficient. [Methods] Based on the Holocene stratigraphic section of the Xingaifang Flood Diversion Channel in the North Branch of the Daqing River within the Haihe River Basin, three periods (six occurrences) of paleoflood event deposits since the Holocene have been identified through analysis of stratigraphic sequences, lithological characteristics, sedimentary structures, and indicators such as sediment grain size and magnetic susceptibility. [Results] The flood deposits are primarily composed of fine to medium sand, with low clay and silt content, and high magnetic susceptibility, indicating the input of highly magnetic materials under high-energy hydrodynamic conditions. Using AMS
14C dating, the periods of the three major paleoflood events were constrained to approximately 8383 cal yr BP, 4625 cal yr BP, and 3907 cal yr BP. The Holocene paleoflood sequence of the North Branch of the Daqing River is closely related to fluctuations in the intensity of the East Asian Summer Monsoon and global climatic events, providing a scientific basis for understanding flood disaster patterns in the Haihe River Basin and supporting resilient urban planning in the Xiong'an New Area.