学术活动
Nonlinear dynamics and pattern bifurcations in a model for vegetation stripes in arid environments
2009-06-17
来源:科技处 点击次数:主讲人:Jonathan Sherratt 教授(Department of Mathematics, Heriot-Watt University,UK)
时 间: 6月19(星期五)下午15:30-16:30
地 点: 数学科学学院211 教室
主 办: 数学科学学院
摘 要: In many semi-arid environments,vegetation is self-organised into spatial patterns.The most striking examples of this are on gentle slopes,where striped patterns are typical,running parallel to the contours.I will discuss pattern solutions of a mathematical model for this phenomenon,of reaction-diffusion-advection type.
I will describe the use of numerical bifurcation methods of both the pattern odes and a discretised version of the model pdes.I will show that patterns exist for a wide range of rainfall levels.Moreover,for many rainfall levels,patterns with a variety of different wavelengths are stable,with mode selection dependent on initial conditions.This raises the possibility of hysteresis,and I will present numerical solutions of the model which show that pattern selection depends on rainfall history in a relatively simple way.