Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Shallow water equations for large bathymetry variations   In this study, we propose an improved version of the nonlinear shallow water
(or Saint-Venant) equations. This new model is designed to take into account
the effects resulting from the large spacial and/or temporal variations of the
seabed. The model is derived from a variational principle by choosing the
appropriate shallow water ansatz and imposing suitable constraints. Thus, the
derivation procedure does not explicitly involve any small parameter.

15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph