Meteorology in generally a neglected parameter in urban planning. At the present time, with increasing air pollution and the extension of the urban areas in to the countryside it is becoming very significant to incorporate meteorological considerations in to the planning process. For the air pollution control there is a need for dispersion models to study different types of quantities of emissions, alternative locations for industries, residential and sensitive buildings, width of streets and their relation to the prevailing wind and other meteorological conditions.

In fact, the atmospheric dispersion modeling for an urban planning is complex process but for the enthusiastic urban planner there is a very basic model “Fixed box-model” discussed below: 

 

Obviously, for an existing city we can do nothing about u, H, and L (see illustration above). However, lf we are laying out a new city, we should lay it out to be long and thin, perpendicular to the wind direction (L as small as possible) or else pick a place where H and u are large. These choices will minimize air pollutant concentrations. This generally means not to put your city in a valley; anyway many major cities are in valleys. 

For an existing city the variables which may be manipulated are b and q. We can reduce b by having our upwind neighbors reduce their emissions and to reduce q we must reduce our own emissions.