Dispersion modeling : methodology and new trends

الملخص EN

Dispersion modeling is a technique for calculating the concentration of pollutants emitting into different media.

Depending on the environment considered, they are classified into atmospheric, aquatic (freshwater, river or marine) or terrestrial models.

A dispersion model is a series of computer-coded equations.

Computers are extremely useful for the repetitive calculations required in estimating concentration at a number of receptor locations, from a number of sources.

Gaussian-plume Model GPM is considered the most commonly used model in defining dispersion parameters and associated concentration of pollutant.

It has been used since 1960.

This model is applicable to ideal conditions of uniformity and steady state under which the data do not change with time and distance.

It can only be applied on a short travel distance of about 10 km and smooth terrain.

On the other hand, the impact of severe accidents such as Fukushima Daiichi event, March 2011 and the Chernobyl accident 1986 were on a regional scale greater than 200km.The objective of this work is to review the basic dispersion models and the approaches used in some countries