Superposition of local zoom models and simultaneous calibration for 1D-2D shallow water flows

We address the problem of coupling 1D St-Venant equations (Shallow Water) with 2D ones, as applied to floodplain flows (river hydraulics). Continuous coupling conditions are derived, while numerical coupling is done using optimal control processes. In a variationnal data assimilation context, this approach allows to couple both models and assimilate data simultaneously. Two different versions of Joint Assimilation Coupling algorithms are proposed and compared. Numerical results show the potentialities of algorithms proposed.