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In this paper, a mathematical model, a numerical algorithm for the process of transfer and diffusion of harmful substances, is developed, which takes into account the wind speed in three directions and the rate of deposition of aerosol particles on the underlying surface, as well as the capture of particles by vegetation elements, which play a significant role in the dynamics of the object of study. In order to integrate the task, an implicit finite-difference scheme and an algorithm with the second order of approximation in terms of time and space variables were developed with the help of which numerical calculations can be carried out on a computer system, on the basis of which it is possible to investigate and predict the ecological state of the industrial region under consideration. To investigate the adequacy of the developed mathematical apparatus, computational experiments were carried out on a computer, the results of which were compared with full-scale data of a real production facility located in the Tashkent region of Uzbekistan. [ABSTRACT FROM AUTHOR]

The spread of air pollutants in the atmospheric boundary layer is mainly conditioned by complex dynamic processes of the air mass movement and turbulent diffusion. Therefore, in meeting the challenges of monitoring and forecasting the ecological conditions of the atmosphere, first of all, it is necessary to take into account the air flow characteristics and the laws governing their changes. In this regard, one of the essential aspects in studying of the air flow structure is consideration of the dependence of the wind profile on the atmospheric stability and surface roughness. Thus, this work purpose is to study the influence of the vertical wind profile on the process of the spread of harmful emissions in the atmosphere based on the developed mathematical tools and GIS technologies. The results of computational experiments on determination the air flow characteristics at given heights and at various values of the ground-level wind speed and the roughness coefficient are presented in the paper, as well as the results of numerical calculations demonstrating the influence of the horizontal and vertical components of the wind speed on the distribution of suspended aerosol impurities in the considered region. [ABSTRACT FROM AUTHOR]

A mathematical tool was developed for monitoring, predicting the concentration of harmful substances in the sur-face layer of the atmosphere of industrial regions for making a managerial decision to protect them from techno-genic factors. Since one of the main factors in the change of the concentration of harmful substances in the atmosphere is aerosol particles, then when conducting a comprehensive study on their distribution, their velocities mixed in the boundary layer of the atmosphere are taken into account with their physical and mechanical properties. In the article, on the basis of the proposed mathematical tool, numerical calculations on a computer were performed and, based on their analysis, it was established that with an increase in the intensity of aerosol generators and horizontal components of wind speed, the propagation area of the concentration of aerosol particles in the atmosphere increases. A detailed analysis of numerical calculations showed that the change in the concentration of aerosol particles in the atmosphere is affected by the coefficient of absorption of aerosol particles, which changes depending on the moisture content of the airmass of the atmosphere; the vertical rate of deposition of particles, which depends on the mass, shape and density of aerosol particles; the coefficient of turbulence that depends on the roughness of the earth's surface. [ABSTRACT FROM AUTHOR]