CLIMATIC AND AIR HYGIENE MAPS AS AIDS FOR PLANNING AND ZONING (EXAMPLE: CLIMATE ATLAS FEDERATION REGION STUTTGART)
5.7 Climate Analysis Map

A significant component of the study mentioned above was the production of climate analysis maps depicting the local-climatic conditions in this region as a cartographic overview (Figure 5/10 and Figure 5/11). The significant bases for this are the data material described above, topographic maps, city maps, land use plans, and aerial photographs.

The classification of climatope and cold-air collection areas is not parcel-specific. Tolerances can range up to 100 m, since both the contextual definition of borders relative transient areas and the accuracy of drawing due to the working material used must be taken into account. Technically-detailed appraisals are necessary for more precise results. The signatures and symbols used in the maps correspond largely to the VDI Guideline 3787, Section 1., which is required by 2013.

Climatopes

Climatopes describe geographic areas with similar microclimatic characteristics. These are distinguished primarily by the daily thermal variation, the vertical roughness (wind field disruption), the topographical situation or exposure, and above all by the type of material land use. The level of emissions is included as an additional criterion for special climatopes. Since the microclimatic characteristics of built-up areas are determined significantly by the material land use and especially by the type of development, the climatopes are named after the dominant land-use type or building use.

Water Climatope

The water climatope (especially for large bodies of water) has a compensating thermal influence relative to its surroundings due to low-intensity daily and yearly variations; in summer, the air temperatures during the day are lower and at night higher than in surrounding areas. The water climatope is characterized by high levels of air humidity and wind.

Open Land Climatope

The open land climatope (Figure 5/12) exhibits extreme daily and annual variations in temperature and humidity in addition to very small changes in wind flow. Thus an intensive production of fresh and cold air is associated with this climatope. This applies in particular to expansive areas of meadow and arable land as well as to open fields with very few trees.

Forest Climatope

The forest climatope (Figure 5/13) is characterized by strongly-dampened daily and annual variations in temperature and humidity. While relatively low temperatures and higher air humidity prevail underneath the canopy because of shading and evaporation during the day, relatively mild temperatures are present during the night. In addition, the leaf canopy works as a filter against air pollution, so that the forest climatope functions as a regenerative zone for the air and as a recreational space for people.

Greenbelt Climatope

Green spaces such as parks in developed areas (Figure 5/14) work to balance their built-up and usually overheated surroundings via their relatively extreme daily variations in temperature and humidity and the associated production of cold, fresh air. Larger green spaces can serve as ventilation corridors. Green spaces with thick tree cover in developed areas use their shading to create cool balancing areas with high air humidity relative to the warmed surroundings.

Garden City Climatope

The garden city climatope (Figure 5/15) includes built areas with open one- to three-story development and rich green spaces. All climatic elements are only slightly altered relative to the open space climatope, although a noticeable nightly cooling occurs and regional winds are not significantly impeded.

City Periphery Climatope

The city periphery climatope (Figure 5/16) is defined by dense detached buildings, rowhouses, or development that incorporates green spaces and takes up entire blocks, all of which can reach up to three stories in height. The climatope can also be characterized by freestanding buildings of a maximum of five stories surrounded by green spaces. Nightly cooling is strongly limited and significantly dependent upon the surroundings. Local wind and cold air flows are hindered, while regional winds are strongly impeded.

City Climatope

Multiple-story enclosed development with small proportions of green space and freestanding skyscrapers characterize the city climatope (Figure 5/17). Strong heating during the day contrasts with very little cooling at night. Through this process, there arises a heat-island effect with low air humidity relative to the surroundings. The dense and tall development influences the regional and super-regional wind systems to a substantial extent, so that air exchange is limited and a high aggregate level of air pollution is present. In street canyons, both high air and noise pollution and gust-like wind turbulence are found.

Core City Climatope

Dense and tall central-city development (Figure 5/18) with very little green space leads to strong heating during the day and the production of a clear heat island effect with lower-than-average humidity during the night. The massive built environment together with the resultant heat island produces a significant influence on regional and super-regional winds. An altogether high level of air pollution is present. In street canyons, gust-like wind turbulence arises along with high levels of air and noise pollution.

Commercial Climatope

The commercial climatope ()Figure 5/19 corresponds largely to the climatope of dense development; that is: Heat island effect, low air humidity, and substantial wind field disruption. In addition, expanded access roads and parking lots as well as heightened emissions are present. Intensive cooling is visible in the nightly heat image, in part at the roof level of large buildings (especially those with sheet metal roofs), while the streets and parking lots surrounded by buildings remain warm.

Industry Climatope

The industry climatope is comparable with the city and core city climatopes, but also exhibits large transportation-related surfaces and significantly higher emissions (including land uses that require special permission under emissions law). A significant heat island forms during both day and night because of extensive sealed surfaces, although the roofs of buildings cool off partially. The air masses near the ground are warmed, dry, and enriched with pollutants. The massive building forms and the warming near the ground significantly alter the wind field.

Railroad Climatope

The railroad climatope is characterized by intensive warming during the day and quick cooling during the night; however, surface temperatures are higher than in the open land. The train tracks are open to the wind because of their sparse covering and often serve as air induction passages or air exchange surfaces in built-up areas. Railroads are considered to be a climatope only in the presence of widths greater than 50 m; that is, only in the case of multi-track railroad lines.

Cold Air Areas and Characteristics of the Relief Structure

The ventilation of built areas with cold air flow has a significant function, especially during low-exchange weather conditions. Areas for cold air production and collection, which provide the nightly fresh-air supply, are therefore characterized distinctively in the climatic map. Also depicted are cold air blockage areas, narrow sections of valleys, winds descending from slopes, mountain and valley winds, and air induction passages for regional winds, along with data for air pollution.

Pollution from Traffic Emissions

Main traffic thoroughfares are divided into three groups on the basis of their average daily traffic counts, and are depicted differentially via the widths of the corresponding map lines.

Pictograms

Pictograms are used to characterize areas with heightened home heating or traffic emissions, intensely-emitting enterprises, and high particulate and heat emissions in the respective climatopes. Further pictograms make reference to local idiosyncrasies of importance for the land areas in concern.

The pictogram Immissions Pollution emphasizes locations with high levels of air pollution in areas at risk of ground inversion effects. These are usually cold air collection areas that cool strongly at night and that exhibit high air pollution values because of nearby pollutant emitters.

Ground/Valley Fog arises frequently in valleys and in areas at risk of ground inversion effects. The designation for elevated Inversion refers to expanded and dominant heat islands in built-up areas. The relatively high surface temperatures and the associated turbulence do not create ground inversions (cf. Figure 3/20 in Chapter 3.3.2); rather, the lower boundary of the inversions lies several decameters above the ground.

The variation of the windfield give a hint to buildings with more than 10 stories or especial hills (dumps) where the wind is changed.

The wind rose depicts the percentage distribution of the average annual frequency of wind direction at a given measurement location.

The Air Pollution Windrose combines the windrose described above with immissions measurements and gives the average measured pollution concentration under the influence of the respective wind directions.