High settlement densities correspond to large numbers of inhabitants affected by this problem area. Therefore, air quality is one of the main problems to be solved, not only in urban regions but also in the surrounding rural areas serving as fresh air reservoir.

In areas of fresh air production and on their corresponding transport routes, called ventilation paths, air pollution level should be maintained on the lowest possible level to enable supply of the settlements with air masses of high quality. Emissions ought to be reduced if the funcitonality of theses areas and paths is already inflected by emissions.

In areas with high settlement densities governed by reduced ventilation or in areas of cold air accumulation reduction of air pollution is a necessity due to the in most cases already existing high level of air pollution and their inherent tendency to accumulate pollutents as vertical air mass exchange is low compared to other ventilation situations (e.g. undisturbed ventilation).
 

			Maintain transport of fresh air
			Reduce air pollution in sensible areas

Fig.: Basel and its surroundings as an example for the classification of the problem-area air quality
        (corresponding to a map scale of 1:100.000)                             

For a detail scene of the city of Basel corresponding to a map scale of 1:25.000 click here

For further, more detailed information see publication list or contact Dr. Dieter Scherer or Dr. Ute Fehrenbach.