A Study for the Dynamics of Dunes in Various Environment

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In this project, using computer simulations and theoretical analysis, we investigated the pattern formation process of dunes and their dynamics in various environment.Specifically, i) pattern selection mechanism of dunes under unsteady wind, ii) pattern formation of dunes in semi-arid region, iii) dynamics of interacting barchans, and, iv) pattern dynamics of river channels, are intensively studied.For these respective subjects, we found that i) the selection mechanism of dunes' trend under unsteady wind is simply explained by the superposition of linearly unstable modes, ii) the formation of vegetated dunes, especially parabolic, are simulated using a inter-suppression dynamics between plant growth and sand transport. iii) size distribution of barchans can simply be explained using the group-dynamics of dunes. iv) dynamics of river channel is treatable using a similar model as that for dunes.Through the research process of these subjects, we got fundamental methodology for the unified mathematical treatment of various geo-morphological processes, which is the next issue of our study.