基于尖点突变的河型稳定性判定方法

冲积河道的自我调整过程是多因素相互作用的复杂响应过程,对冲积河道河型的稳定性和调整方向进行判定是河流动力学的基本问题之一。根据突变理论中的尖点突变模式,采用影响河道稳定性的控制变量与状态参量,建立河道平衡状态方程,并推导得到河流状态判别式。通过对100多条天然河流及实验河段进行验证,结果显示这一方法能判定冲积河流的河型稳定状态,并对其调整方向作出预测,为实际工程中的河流整治提供一定的参考。

A cusp catastrophe model for alluvial channel stability

The self-adjustment of an alluvial channel is a complicated process with various factors influencing the stability and transformation of channel patterns.Although the formation of alluvial channels has been extensively studied,the problem of the alluvial channel stability still remains to be systematically resolved.This paper presents a cusp catastrophe model for alluvial channel stability.The model enables the discrimination and the prediction of the equilibrium state for channel patterns.Equations of equilibrium state of alluvial channel patterns and the transformation of channel patterns are established based on the cusp model of catastrophe theory and choosing appropriate state variables.The result shows that the model predictions in about 100 natural rivers are consistent with field observations.The proposed cusp catastrophe model is applicable to the study of natural river regimes and to assisting the decision making in river engineering.