Comparative Study of Numerical Schemes Used for One-dimensional Transport Modelling

The equation of mass transport is used to simulate such environmental problems, like contaminant spreading in rivers. In most of the cases the 3D phenomenon can be simplified to 1D problem. This supposes that the contaminant has already been well mixed in both transversal and vertical directions. This approach is really considered as third phase of matter mixing, where the phases, provided a point source of pollution are the following (van Mazijk, 1996, Jobson, 1997): in the first phase vertical mixing (completed within 50-100 average river depths) is predominant. In the second phase transversal mixing over the cross sectional area of the river (completed within 100-300 river widths) is predominant. The transversal mixing distance is sometimes very long, therefore the second phase is often not separated from the third phase, in which the longitudinal mixing is predominant.