Decoupled simulation

Advection-Dispersion and Hydrodynamic simulations are two different simu­lations, but are often performed simultaneously: in that case, the Advection-Dispersion simulation uses the raw results from the Hydrodynamic 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 Advection-Dispersion simulation is performed and it reads the Hydrodynamic data from a result file. In such a decoupled simulation, only the Advection-Dispersion calculations are performed and the simulation time is highly reduced. To apply this mode, enable the 'Decouple Advection-Dispersion and Hydrodynamic simulations' option, and then select the hydrodynamic result file using the Browse '…' button.

Note: The decoupled option is only available when the 'Data' checkmark is ticked and the 'Sim.' checkmark is not ticked for the Hydrodynamic module, in the Modules menu.

Note: When running a decoupled simulation, it is recommended to pay atten­tion to the selected input hydrodynamic result file. Using a regular result file, with instantaneous Water level and Discharge items, there is a risk to intro­duce mass errors in the Advection-Dispersion simulation if the hydrodynamic result file doesn't store all simulation time steps. To avoid this, the result file should either store all time steps from the Hydrodynamic simulation, or should be a special result files tailored for the decoupled simulation and con­taining the average discharge for each saved time step. This special result file can be saved during the Hydrodynamic simulation, from the 'Decoupling' menu.