黄河下游高村-孙口段冲淤变化及影响因素定量分析

Quantitative Analysis of Erosion and Deposition Changes and Influencing Factors in Gaocun-Sunkou Section of the Lower Reaches of the Yellow River

为探究黄河过渡段河道滩槽演变规律,采用实测水沙和大断面数据,分析近年来高孙段河床冲淤、水沙条件和河床形态的演变,以年和汛期为时间尺度,用灰色关联度分析河槽冲淤量与水沙条件及河床形态的关联程度。结果表明,近年来高孙段以冲刷为主,汛期是年内输沙的主要时期;高村断面来沙系数可以分为波动减小(2002~2017年)和快速增加(2018~2019年)两大阶段,而河床形态中水力半径和宽深比变化趋势完全相反,糙率存在增大趋势;高村断面的水沙条件及河床形态与高孙段河道冲淤具有较高的关联程度,河床形态比水沙条件具有更高的相关性。

In order to study the evolution law of the channel trough in the transition section of the Yellow River,channel erosion and deposition,water and sediment conditions and riverbed morphology in the Gaocun-Sunkou section were analyzed using measured water and sand and cross-section data.Using annual and flood seasons as the time scale,the correlation degree of river channel erosion and siltation with water and sediment conditions and riverbed morphology was analyzed by grey correlation.The results show that the Gaocun-Sunkou section has been dominated by erosion in recent years.The flood season is the main period of sand transport during the year.The incoming sand coefficient of the Gaocun section in recent years can be divided into two stages fluctuating decrease(2002-2017)and rapid increase(2018-2019).The changes in hydraulic radius and the width-to-depth ratio of riverbed morphology have opposite trends,and the roughness tends to increase.The water and sediment conditions and riverbed morphology of the Gaocun section have a high degree of correlation with river erosion and siltation in the Gaocun-Sunkou section.The river bed morphology has higher correlation than water and sediment conditions.