A robust time-split linearized explicit/implicit technique for solving a two-dimensional hydrodynamic model: Case of floods in the far north region of Cameroon

This paper develops a time-split linearized explicit/implicit approach for solving a two-dimensional hydrodynamic flow model with appropriate initial and boundary conditions. The time-split technique is employed to upwind the convection term and to treat the friction slope so that the numerical oscillations and stability are well controlled. A suitable time step restriction for stability and convergence accurate of the new algorithm is established using the L∞(0,T; L2)-norm. Under this time step requirement, some numerical examples confirm the theoretical studies and suggest that the proposed computational technique is spatial fourth-order accurate and temporal second-order convergent. The case of floods observed in the far north region of Cameroon is also considered and discussed.