CONTINENTAL MODELING OF AIR POLLUTION USING ArcGIS

Abstract

There are many physical and chemical process associated with long range transport of air-pollution. Out of those there are only five main phenomena playing important role in the atmosphere which can be described in form of mathematical terms while developing the air pollution model. Those processes can be broadly classified as horizontal and vertical (convection plus eddy diffusion) and chemical transformation of the pollutants in the atmosphere as well as deposition on the earth surface. The continental model equations take the form of partial differential equations which are very difficult to solve analytically, therefore in the present work these equations are solved by using numerical methods. In the present work emphasis is given on the modeling of the horizontal transport of pollutant by taking basic assumptions for the wind velocity, mass burning rate of pollutant from the source etc. Model equations have been developed by taking suitable control volume and are solved by using finite volume method. MATLAB Simulation results give the idea about concentration profile of a pollutant along X and Y co-ordinate of horizontal direction in different time period. Then the model has been used to predict the concentration of SPM at various meteorological stations and is compared with the observed concentration in those stations for the Jaipur Indian Oil Corp. Fire Episode, 2009. ArcGIS is used to determine the geographical locations and distance between meteorological stations for this purpose. Results reveal importance of advection over convection as diffusion in lateral direction is found to be much higher than that of molecular diffusion.