Difficulties of modelling of pollutant dispersion in the environment and ways to overcome them

Many dispersion models for sources have been developed to assess the impact of traffic on the air pollution levels near roads, which arc in most cases based on the Gaussian equation. The theoretical simulation of the pollutants dispersion near the highways practically is impossible due to the continually volatile turbulence, the direction of wind and wind-power; therefore only the semi-empirical simulation methods based on the measurement results have to be applied for simulation. Most of researchers choose various pollutants dispersion models for the evaluation of traffic emissions to atmosphere such as theoretical, empirical or semi-empirical models. Many experimental studies gave evidence, that such kind of models tend to overestimate concentrations in low wind speed conditions or when the wind direction is almost parallel to the street orientation. The paper concerns the mathematical models which can describe and predict atmospheric pollution. The theoretical and half empiric expression are used to describe models.