Distribution pattern and characteristics of sedimentation in the Lower Yellow River
To reveal the distribution pattern and characteristics of sedimentation along the Lower Yellow River(LYR),a series of statistical analyses were conducted based on the measured data of sedimentation in each section of LYR from 1952 to 2021.It was found that:(1)There are seven longitudinal distribution patterns of sedimenta-tion,among which the whole-line erosion,the whole-line deposition,the upper erosion and lower deposition,the upper deposition and lower erosion are the four main patterns.The critical position of the upper deposition and lower erosion pattern is near Sunkou station,and the critical position of the upper erosion and lower deposition pat-tern is in the wandering river section.There is a big difference in the contribution rate of each pattern to the overall sedimentation of the river channel.The largest contribution rate to the amount of erosion is the pattern depositing in the middle and eroding in the upper and lower reaches,and the largest contribution rate to the amount of deposition is the pattern of whole-line deposition.(2)The variation process of the longitudinal distribution pattern of sedimen-tation since 1952 can be divided into four stages:1953-1959,1960-1985,1986-1999 and after 2000.(3)The distribution of the amount of sedimentation in each river section is mainly a normal or skewed distribution centered on 0 point.The fluctuation of the amount of sedimentation has the trend of downstream decreasing at the multi-year scale and the periodic characteristics of a long time of erosion will silt,a long time of erosion will scour.(4)The overall frequency of sedimentation in each river section is not much different,reflecting the equilibrium tendency of river sedimentation.In the past 70 years,only about half of the sediment deposited at the riverbed in the Lower Yellow River has been washed away.The cumulative amount of sedimentation from Huayuankou station to Sunkou station is close to 80％of the total amount of sedimentation in the lower reaches,and the river below Sunkou station is very small.(5)The whole-line erosion is the main pattern after the operation of the Xiaolangdi Reservoir.The sediment deposi4ted in the early stage of the Xiaolangdi-Huayuankou section is basically washed out,and the Jia-hetan-Aishan section only washed away 20％to 30％of the sediment deposited in the early stage.The results sum-marized the distribution patterns of sedimentation and analyzed the distribution characteristics of sedimentation,which was helpful to deepen the overall understanding of sedimentation phenomena in the Lower Yellow River.
Lower Yellow Riverthe amount of sedimentationlongitudinal distribution patternwhole-line ero-sionwhole-line deposition
万方数据
维普
