黄河下游游荡性河段主流线调整与水沙关系研究

Study on relationship between changes of the main streamline and hydraulic conditions in the wandering reach of the lower Yellow River

通过对多年河势资料的统计整理，分析了主流线的调整规律。研究表明，主流线弯曲系数与汛期水量和洪水径流量成反比，与汛期平均含沙量关系不大，但与年径流量也有关；主流线弦高与汛期水量之间无明显增减关系，对于长河段平均意义而言，弦高基本稳定在1000～1500m之间，而弦长与汛期径流量有明显的正比关系；近年来，主流线弯曲系数增加，同时河湾个数增多，但两者之间并非简单的线性关系；主流线长度随汛期水量增加而减小，且其递减率与汛期水量成线性统计关系。

The paper presents the statistical results about the changes of main streamlines in the wandering reach of the Lower Yellow River. The results show that the sinuosity changes in an adverse proportion to flow amount in the flood season, but exhibits no relationship with mean sediment concentration in the flood season. Sinuous amplitude of the main streamline bears no apparent relationship with flow amount in the flood season. The mean sinuous amplitude for the long reach ranges from 1000～1500 m, and the main streamline chord has been found to change apparently in proportion to flow amount in the flood season. Although sinuosity and number of bends in the reach increased in the past years, they don＇t bear a simple linear relationship. With the increase of flow amount in the flood season, the main streamline length decreases, but its decreasing ratio appars a statistically linear relationship with the flow amount.