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山区河流推移质运动与河床结构发育程度之间紧密联系,认识这种联系有助于揭示山区河流的推移质输沙规律。通过专门设计制作的推移质运动观测-视频采集系统和河床结构发育程度测量装置,对河床结构发育良好、部分发育及无河床结构(平整床面)三种典型床面条件的山区河流推移质颗粒运动进行了观测分析,并初步研究了推移质运动和河床结构发育程度的制约关系。试验发现,河床结构发育良好时,推移质输沙率很低,推移质输沙主要通过跃移运动实现;河床结构部分发育时,颗粒跃移强度上升,并逐渐有颗粒突破结构束缚,在床面滚动(间或滑动);无河床结构条件下,滚动(间或滑动)和跃移输沙均为推移质输沙的重要方式;如果水沙浓度达到一定值,可能发生层移质运动,滚动(滑动)输沙超越跃移输沙成为推移质输沙的主要方式。宏观上看,山区河流推移质输沙和河床结构发育程度之间相互制约。对同一河段,当水流功率不变时,推移质输沙率和河床结构发育程度之间在对数坐标下基本呈线性负相关关系。
The close relationship between the plutonic movement of mountainous rivers and the degree of structural development of the riverbed can help to reveal the rules of transgressive sediment transport in mountainous rivers. Through the specially designed plutonic movement observation - video acquisition system and river bed structure development degree measuring device, the three kinds of typical bed conditions of well-developed river bed structure, partial development and no bed structure (flat bed) The movement was observed and analyzed, and preliminary study of the relationship between the plutonic movement and the degree of structural development of the riverbed. It is found that when the structure of the riverbed is well developed, the rate of sediment transport is very low and the transgressive sediment transport is mainly achieved by the leaping movement. When the structural part of the riverbed is developed, the transition strength of the particles increases, and the particles break through the structure and gradually become trapped. (Rolling or sliding) and transgressive sediment transport are all important ways to transport sediment under no-riverbed structure. If the concentration of sediment reaches a certain value, it may cause bed-shifting movement and rolling Sliding) Sediment transgression transgressing transgressive sediment transport becomes the main mode of transiting sediment transport. From the macroscopic point of view, the sediment transport in mountainous rivers and the structural development of riverbed are restricted by each other. For the same section, when the water flow rate is constant, there is a linear negative correlation between the bed mass transport rate and the degree of structural development of the river bed under logarithmic coordinates.