“…Many upwind (see, e.g., [1,2,5,9,10,18,22,31,33,37] ) and central (see, e.g., [6,8,15,23,28,40,41,45] ) schemes for the shallow water system (1) , which is a hyperbolic system of conservation (if B x ≡ B y ≡ 0) or balance (if B is not a constant) laws, have been proposed in the past two decades. Roughly speaking, the main difference between upwind and central schemes is that upwind schemes use characteristic information and utilize (approximate) Riemann problem solvers to determine nonlinear wave propagation, while central schemes are based on averaging over the waves without using their detailed structures.…”