A Scale-Coupled Method for Simulation of the Formation and Evolution of Aeolian Dune Field

摘要

In this paper, a scale-coupled method for the formation and evolution of aeolian sand dune fields is proposed. It successfully reproduces various dune patterns and the whole development process of a dune field of several square kilometers during several decades. Based on our simulations, we investigate the influence of sand supply, wind velocity, and wind direction to the dune patterns and dune speed in the dune field in quantity. Compared with the existing dune field model, we solve the correspondence problem in length-scale and time-scale between the simulated and the actual formation and evolution of a dune field. Our results on the variations of the dune speed with the dune height and the relation between the thickness of sand supply and the average dune height both agree with the results measured in field in quality and in quantity. Besides, we present the influence of wind velocity and sand diameter to the maximum dune height in a dune field and replay the 'solitary wave'-like behavior of two barchan dunes in a dune field. These results are not only beneficial to understand the dynamical characteristic of a dune field more comprehensively and more clearly, but also meaningful for further prediction of the migration trend of deserts under global climate change and the investigation of the aeolian geomorphology on Mars.