Author(s): Yuanjian Wang; Enhui Jiang
Linked Author(s):
Keywords: Hyper-concentrated flood; Flow instability; Wave equation; Froude Number; Lower Yellow River
Abstract: Phenomenon of amplifications of hyper-concentrated flood occur in the Lower Yellow River (LYR) at times. This study took the phenomenon as a result of flow instability. Derived from the analysis on the characteristic of wave equations, mechanism and criterion of flood amplifications were explored in this paper. The results show that: if velocity of dynamic waves is greater than that of. kinetic waves, spreading velocity back of wave will be greater than that in front, flood amplifications occur. In the condition of clear water, the criterion of flood amplifications is Fr> 1. 5 (Fr is the Froude Number) ;While for hyperconcentrated flood, as the structural change of the resistance equation, the criterion will be changed to Fr< 1. That is the reason that flood amplifications can be observed in sediment-laden rivers like LYR.
Year: 2015