Auxiliary Variable-based Balancing (AVB) for source term treatment in open channel simulations

► An auxiliary variable (AV) is used in place of the flow variables in the flux estimate. ► Preserves static and steady-states equilibrium for non prismatic channels. ► Applied to HLL, Roe, Q-scheme and 3 AV: water elevation, specific force, hydraulic head. ► Three steady state configurations and two highly transient test cases (dam-break). ► Best results are obtained with the hydraulic head as AV.