蜿蜒性河流演变机理研究

Research on mechanism of evolution for meandering river

从宏观规律入手,采用概化方法研究了蜿蜒性河流的演变机理。在观察分析蜿蜒性河流演变规律的基础上,提出了弯曲河流的演变过程,即河流演变初期表现为沿轴线左右摆动,因受柯氏力的影响轴线逐渐弯曲,由于摆幅的增大和轴线曲率半径减小,使河流呈现出由顺直-微弯-蜿蜒-裁弯的演变过程。

On the basis of observing and analyzing the data of evolution of meandering rivers, the process of riverevolution was studied from macroscopic view in generalized condition. It is discovered that a river occurs to wa-ver along a river axis at initial stage, then the axis bends gradually; due to Coriolis Force action, the center ofcurvature is usually located at the south side of the river and the bending reach of south side develops quickerthan its north side; as a result, the bending radius of axis reduces and wavering extent increases, thus the typicalevo1ution process must be developed gradually from straight stream→tiny bending river→meandering river andto cut-off finally.