Availability of Public, Near-residential Green Spaces 2016
The analysis of the stock of green space covered all green spaces in the area of the city with recreational qualities.
This analysis includes the green spaces and playgrounds presented in the Green-Space Information System (GRIS). It also involves both green spaces created as part of compensatory measures, such as the Rudow-Altglienicke landscape park, and areas maintained by Grün Berlin GmbH, such as the Britz Garden and the Gardens of the World (Gärten der Welt) in Marzahn. The grounds of the “Prussian Palaces and Gardens Foundation Berlin-Brandenburg”, such as the Charlottenburg Palace grounds and the Glienicke Park are included, too. Berlin’s forest areas are also used to determine the number of residential blocks in the intake areas near the forests and the forest edges.
The Botanical Garden and the two Zoos are not included in this availability analysis, as they are neither freely accessible public green spaces, nor are they public green spaces with affordable entrance fees.
Similarly, numerous smaller tree-lined “pocket parks”, covering an area of less than 5,000 m2 have been excluded both from the analysis and this update. Although some of the facilities represent important climate-effective areas, which shape the urban space and also play an important role in terms of biodiversity, they generally do not offer sufficient space for typical recreational uses, including exercise and leisure. The following criteria were used for the assessment:
Facilities for near-residential recreation must have a minimum size of 0.5 ha, to make type-specific use possible. For green spaces bisected by streets, the resulting segments are considered only if one of them is larger than 0.5 ha. However, smaller areas can also be included, provided that they directly border on other green spaces, and are thus located in the context of the green network structure.
Moreover, it is assumed that green spaces, which are greater than 10 ha and are assigned to the “near-development” category are needed and visited by residents living nearby, in the manner of near-residential use. Therefore, for the purposes of this analysis, these larger facilities have also been assigned intake areas, and calculated accordingly.
Unhindered accessibility to the green space must be guaranteed. Obstacles include railway lines, large bodies of water, and motorways.
Noise pollution and air pollution diminish the recreational value of spending time outside. Since detailed measurements and/or prepared data regarding the air quality in green spaces was not available at the time of compilation, the pollution factor is limited here to the element of traffic noise.
For green and open spaces, German Industrial Standard (DIN) 18005, 5.87, Sound Protection and Urban Development for Urban Development Planning, specifies a limit of 55 dB (A). With free acoustic propagation, this limit can be reached on a city street with a speed limit of 50 km/h even at a vehicle load of 2,000 motor vehicles per day. Main thoroughfares are, as a rule, burdened with far more than 10,000 motor vehicles per day (cf. Environmental Atlas Map Traffic Volumes, 07.01, Edition 2011). This corresponds to a noise pollution of more than 60 dB (A), and frequently more than 70 dB (A). Patchy vegetation in green spaces provides no noise buffer. A reduction of the noise can be ascertained solely at increasing distance from the source of the noise. Due to the location of many green spaces on heavily travelled streets, a large number must be considered heavily noise-polluted, and would therefore be classified as unsuitable for recreation. As a minimum requirement, it was stipulated that at least a part of the open space had to be unaffected by major environmental stresses. This criterion was further specified to indicate that an open space on a heavily-travelled street, with a noise level of more than 70 dB (A), would only be classed as suitable for recreation if it had a minimum depth of 100 m from the street, or a minimum size of 1 ha. Minimum size and/or depth should guarantee that a visit to the open space would be possible at a distance from the street. Green spaces larger than 1 ha were thus classified as suitable as a rule.
Ascertainment of Intake Areas
Each green facility is assigned an intake area (green facilities located in the adjacent State of Brandenburg are not included).
For smaller facilities, the centre is chosen as the point of origin of the radius; for larger spaces, the entrance area was used (approx. 100 m inside the open space). The intake area calculated for near-residential green space, for a distance of between 300 and a maximum of 500 m around that green space, only takes complete blocks and block segments into account.
Since the accessibility of a green space can be reduced by existing barriers, these will be addressed next. Barriers include e.g. rivers and canals, railroad lines, airports and motorways. If such barriers exist around a green space, the intake area is corrected.
Wooded areas are also assigned an intake area. It is assumed that the edges of forests can to some extent assume the functions of a near-residential open space. Forest edges were evaluated so highly as recreational areas that throughout Berlin, inhabited blocks in an intake area of 500 m from forest areas are categorized as having green space available.
The same is done in some cases even for well-structured farmland areas, or other high-quality open spaces (for example in Gatow, at Großglienicker Weg or Krugpfuhl Buchholz); the surrounding inhabited blocks are likewise categorized as provided with green space, and are assigned an intake area.
Recreational use of agricultural areas is possible only to a limited degree, and only in some parts of the area; however, in the Berlin portion of the Barnim region, the areas accessible by footpath are included in the assessment. For this recreational area, the agricultural segments, including fields, meadows and pastures, are part of the park landscape.
Calculation of the Degree of Availability
According to the standard value or benchmark applicable in Berlin, the availability of public green spaces to the population at a level of 6 m2 or more of near-residential open space per inhabitant is considered sufficient. Determining the m2 of green space per inhabitant in a defined intake area yields the relative degree of availability of public green space. Based on this value, the degree of availability (m2 of green space per inhabitant) is broken down into four levels: availability provided (standard value is met), availability poorly provided (50% or more of the standard value), availability minimally provided (less than 50% of the standard value) and availability not provided (less than 0.1 m2 per inhabitant) (cf. Landschaftsprogramm Artenschutzprogramm – Begründung und Erläuterung [Landscape programme protection of species programme – explanation and commentary], SenStadtUm 2016, p.91). For the calculation of the respective degree of availability, the number of inhabitants in the intake area of a green space is aggregated and the size of the green space (in m2) is divided by the calculated population.
For the calculation, all blocks are included in which more than ten inhabitants live per hectare. This so-called population threshold is established for the planning process to ensure that the automated analysis also considers the population living in areas with structure types with predominantly commercial, services, trades and industry, and those with “other uses”, without however including individuals, those living in industrial areas for caretaking or security purposes. In this way, more inhabited blocks can be included, especially in inner-city locations with key metropolitan use types, or mixed-use areas (cf. Figure 2).
Provision with Private Green Space
Private and semi-public areas can compensate for a lack of public green space. For this reason, the structure of residential buildings is used to determine the overall availability of open space: it is an indicator for the supply of private open spaces. Single-family housing developments, for example, have yards. In the block edge development of the Wilhelminian period, on the other hand, it is difficult to spend time in semi-private green spaces, other than in courtyards or on balconies. In order to ascertain not only the availability of public green areas to the population, but also that of private green space, the urban structure recorded in the Environmental Atlas (cf. Statistical Base) was divided into three structure type categories, each assigned different proportions of private open space (high – medium -low, cf. map legend). Examples of these respective types include single-family home areas, areas with row-house developments, and in contrast to these, the inner city residential blocks of the Wilhelminian period.
Deduction of the Housing Type
The building structure is examined as an indicator for the available share of private open space. Areas with different building structures, but with comparable shares of private/semi-public open spaces, are lumped together, and classified into three categories (cf. Fig. 1):
Extremely slight share of private/ semi-public open spaces
This involves predominantly areas of closed block development (before 1918), including all preservation-oriented reconstructed blocks integrated into this building structure. In addition, core and mixed areas are counted in this category.
Slight to medium share of private/ semi-public open spaces
To this category belong all building structures which display large quadrangles or strips of green space (development from the ’20s and ’30s and/or from the ’50s and ’60s), and the large estates with generous green spaces between the buildings. Furthermore, the redeveloped apartment blocks of the ’60s and beyond also include closed block development which was decored completely, and thus has larger open spaces. The compact, high-rise developments of the ’90s are also included here.
Medium to high share of private/ semi-public open spaces
This category includes all open development (for instance single-family or row-house development), and also the low density single-family housing developments of the ’90s. to a large extent, the buildings have their own gardens, so that the share of private green space is very high.
In relation to the 16 urban structure types, defined by the Environmental Atlas (cf. Statistical Base), the three categories shown in Figure 2 are then divided into the structure types with predominantly residential use, those with predominantly retail, service, commercial and industrial use, and those with other uses.