Mathematical Model Of Long-term Evolution Process Of Meandering Rivers

Explore the long-term evolution is a basic problem of river dynamics. Mathematical model was widely used in the research of the long-term evolution process of meandering rivers, in this article, I want to establish mathematical model to simulate and explain the evolution of natural river dynamic process. Will bend in the evolution of the long-term research theory to practice, guiding people recognize and develop and utilize the river resources correct, better carrying out watershed planning, river regulation and ecological environment restoration and other works.In this paper, the basic theory of nonlinear river dynamics theory has been briefly discussed. This paper introduces the evolution process of the river equilibrium and non-equilibrium problems and establishes river's balance and disturbance development equation on the basis of the theory.Using the natural model method, an indoor natural river has been successfully portrayed with the scouring water. The experiment includes the study of the influence of river channel evolution process duing to different initial river geometric boundary conditions and different flow conditions. Studies reveal that flow is mostly influence to river stretcher amplitude. There are no necessarily relationships among the size of the inflow angle and river's stretcher range and the changes of river bend degrees, when the inflow angle is 300, changes of river width and curvature are more obvious. The inflow angle affects the river evolution in a short-term and has a greater impact in the initial stage of evolution. Subjecting to initial boundary conditions, river's evolution downward is lag and transitivity of curvature changes. This paper analyzes the sediment sorting phenomena in the process of river evolution.The model simulates the long-term evolution process of meandering river and analyzes the dynamic characteristics in the process of evolution. The simulation results show that meandering river has the most unstable wavelength, the evolution of the river start from the most unstable wavelength, disturbance wave can't keep for a long time, the river itself has filter function. Using the mathematical model to simulate the long-term evolution process of Jiyun river, analyzing the deposition process and the evolution trend of upstream, middle reaches and downstream in Jiyun river. Analyzing the effect of the long-term evolution process of Jiyun river on ecological environment and production and life in Haihe basin.