北江下游航道水动力变化对河床变形的响应研究

采用基本站水文分析、二维水动力数值模拟和河床演变分析相结合的方法,通过研究水动力近期的主要变化和河床演变的主要特点,分析得出北江下游航道在径流作用河段水位变化是对河床下切的直接响应,而在下段的感潮河段,中、枯水潮汐作用较强时,水位变化受控于潮汐动力,潮汐动力变化是对河床下切、底坡降变小和河床容积增大的响应,流速变化主要是对平均水深和水面比降变化的响应。

On response of hydrodynamic change to the riverbed deformation of Beijiang river downstream channel

Based on the hydrographic data analysis, 2D modeling and fluvial evolution analysis which are combined to study the main changes of hydrodynamic and features of fluvial evolution, we can get that the water level change is the direct response to the lowering of riverbed in the runoff dominant reaches while it is controlled by the tidal dynamic in the tide affected reaches during the median and lower water level. The tidal change is the response to the lowering of riverbed, deceasing of the bottom slope and increasing of the channel capacity. The velocity change is the response to the water depth and longitudinal slope.