Rainfall-runoff and hydrodynamic simulations are two different simulations, but are often performed simultaneously: in that case, the hydrodynamic simulation uses the raw results from the rainfall-runoff simulation. The present decoupled option is in that case not used.
It is however possible to run them in a decoupled mode: in that case, only the hydrodynamic simulation is performed and it reads the rainfall-runoff data from a result file. To apply this mode, enable the ‘Decouple Rainfall-runoff and Hydrodynamic simulations’ option, and then select the rainfall-runoff result file using the Browse ‘…’ button.
When running a decoupled simulation, the catchments and the river links must be defined as usual.
Note: The decoupled option is only available when the ‘Data’ checkmark is ticked and the ‘Sim.’ checkmark is not ticked for the Rainfall runoff module, in the Modules menu.
Note: When running a decoupled simulation, it is recommended to pay attention to the storing frequency used in the rainfall-runoff result file. This storing frequency should indeed be high enough in order to accurately reflect the runoff fluctuations. If that is not the case, the results of the decoupled hydrodynamic simulation will differ from those that would be obtained with a ‘coupled’ simulation.
