Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transformation of Barchans into parabolic dunes under the influence of
  vegetation   Barchan dunes were found to transform into parabolic dunes and vice versa
when the amount of vegetation on and around them changes. This work presents
the first numerical simulation of this effect. We propose a continuum model for
the density of vegetation. An established sand transport model is used for
simulating the evolution of the dunes.

8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn