Add to ORKGAbstract: A random walk model to describe the dispersion of pollutants inshallow water is developed. By deriving the Fokker-Planck equation, the model is shown to be consistent with the two-dimensional advection-diffusion equation with space-varying dispersion coefficient and water depth. To improve the behaviour of the model shortly after the deployment of the pollutant, a random flight model is developed too. It is shown that over long simulation periods, this model is again consistent with the advecfion-diffusion equation. The various numerical spects of the implementation of the stochastic models are dis-cussed and finally a realistic application to predict the dispersion of a pollutant in the Eastern Scheldt estu-ary is described. Key ...