On the influence of grid resolution on the dilution of desalination brine in hydrodynamic models

Using a simple one-dimensional diffusion equation, this theoretical work explores the dilution of desalination brine in hydrodynamical models that use the discharge approach proposed by Kämpf et al. (2009). Findings demonstrate that this dilution depends strongly on (i) the magnitude of eddy diffusivity and (ii) the numerical grid spacing with significant differences in the salinity predictions. Hence, salinity predictions using this approach are highly unreliable unless validated by field data and should not be used in decision-making processes.