Quality Control of Numerical Models of Marine and Estuarine Effluent Outfalls

Quality Control procedures were developed and implemented on behalf of a UK water company for the procurement of a suite of numerical models of advection and dispersion from effluent outfalls. The paper explains the need for quality control and describes the methods employed. These were a set of technical audits and performance trials. Some interesting technical issues arose from this work. These examined: the sensitivity of shoreline solutions to variations in parameter values; showed that simulations must be of sufficient duration to reach convergence; showed that the surface wind creates a shear dispersion effect which has an important effect on an effluent plume; and investigated the choice of diffusion coefficients with reference to along and across tide diffusivities and the need for consistency between nested models.