2. Climate and air as planning factors
It is difficult to evaluate our
climate, especially urban climate, and to compare it with other planning factors (like air and noise), which have various, even legally binding limit and guide values.
What is required most frequently is not an absolute assessment but a comparative evaluation. In spite of these difficulties, climate has always played an important role in the planning of buildings, estates and towns and cities.
The most significant climatic condition for the building sector is wind: It has an influence on buildings and their stability as well as on the aeration of residential estates and on air hygiene.
While the wind direction is important in the context of the transportation ability of the wind and its influence on buildings and air hygiene, it is mostly wind speed that plays a major role for mechanical forces and the rarefaction of air pollutants.
The following
table 2.1 gives the most significant climatic differences between cities and their surrounding regions.
These climatic changes are not to be judged too negatively. But there is the fact that climatic conditions mostly have an immediate impact on air pollutants and therefore determine air hygiene.
In contrast to the current weather situation, climate data provides information on the situation of individual climatic elements over the course of many years.
There is no fixed measure for climate. It is rather determined by the interaction of the individual climatic elements, and the usual international reference period of time is 30 years.
We want to give a rough outline of a number of climatic elements and derived properties, also in the context of their relevance for air pollution without neglecting the significance of climatic aspects for civil engineering and the planning and operating of heating and ventilation systems. Climatic elements play a significant role for development planning during the drawing up of land use plans and development plans, as climatic concerns have to be considered in the planning phase according to § 1 of the Building Code.
The measuring methods of meteorological factors in the context of air pollution control are presented in the VDI guidelines 3786 Part 2 to 9 (Verein Deutscher Ingenieure, Association of German Engineers).
The climate measuring networks operated by the German Meteorological Service are rather coarsely meshed and only allow for a resolution on the regional scale. Local issues therefore require detailed examination and analyses. Climatology uses statistical methods for the analyses and presents average values and maximum and minimum values as well as frequency distributions and correlations with other factors.
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| © City of Stuttgart, Office for Environmental Protection, Section of Urban Climatology |
