Résumé
We present low complexity models for the transport of passive scalars for environmental applications. Multi-level analysis has been used with a reduction in dimension of the solution space at each level. Similitude solutions are used in a non-symmetric metric for the transport over long distances. Model parameters identification is based on data assimilation. The approach does not require the solution of any PDE and, therefore, is mesh free. The model also permits to access the solution in one point without computing the solution over the whole domain. Sensitivity analysis is used for risk analysis and also for the identification of the sources of an observed pollution.