Figure 1. Example of a green roof in Stockholm. The picture shows a biotope roof in Norra Djurgårdsstaden. The areas with gravel are prepared for installation of PV-modules.
Stockholm Green is an open source calculation module used for calculating the biotope area factor according to the Stockholm methodology (Grönytefaktor, GYF). It also calculates subcategories relevant for the biotope area factor. The calculation module was developed within Ecodistr-ICT project and was programmed by SP Technical Research Institute of Sweden.
• Stockholm Biotope Area Factor (GYF), [-]
• Biodiversity ratio, [-, %]
• Social value ratio, [-, %]
• Climate adaptation ratio, [-, %]
The GYF methodology and what it does
The biotope area factor (BAF) was originally developed in the 1990s in Berlin, Germany to increase green space in the city. It has since been further developed at other locations including the city of Stockholm (here referred to as GYF, Grönytefaktor). This module calculates the biotope area factor of a district, i.e. the area portion of a plot of land that serves as a location for plants or assumes other functions for the ecosystem, in relation to the total area of the plot, in accordance with the model developed in Stockholm, Sweden. The methodology, however, can be used in other cities as it is not dependent on site specific conditions related to the origin city. It was developed to illustrate ecosystem services and encourage the strengthening of local ecosystems and creation of climate-adapted courtyards with high social values. Planners, architects and developers received a concrete planning tool adapted to their way of working, which facilitated and inspired planning and design with ecosystem services.
The Stockholm GYF methodology is a more advanced tool compared to the Berlin BAF tool. It includes many more input parameters and investigates multiple aspects of urban green. The input required is more detailed and will take some time to investigate and collect whereas for the Berlin BAF this is a more simple procedure. Stockholm GYF will, however, provide the user with much more information on urban green and ecosystems in the district.
Berlin Green is a separate module which is also available in the Ecodistr-ICT IDSS platform.
Areas of application
The Stockholm GYF promote greenery that serves several functions, e.g. create green spaces for recreation, delay and purification of rainwater, provide shading and contribute to pollination, and for aesthetic purposes. The GYF is measured as a ratio of the eco-effective surface to the total surface of the district. The eco-efficient surface consists of all the green and blue areas within a district designed according to certain set requirements. Blue surfaces refer to facilities connected to an open storm water management, such as ponds, ditches and rain gardens.
The results are presented as a ratio [-] of ecologically effective surface area to the total land area (district), and the targets should be set by the stakeholders. The GYF target value can vary and references to previous relevant studies should be investigated, normally a factor of 0.6 is used. However, any improvement to the existing GYF is important and even a small change will make a difference to ecosystem services in the area.
Interdependence to other modules
This calculation module is not interdependent to other modules.
References and more information
List of input data
The input data used in the Stockholm Green calculations are listed below. All input parameters are not required to be filled in with the exception of “Total Land Area of Plot”. However, the more information that is supplied the more accurate the result.
Some input parameters are described as contributing (sub-) factors (CF). These are surfaces within the district. To these additional (supplementary) factors (AF) can be added for individual elements or important functions. These, including integer data, are later recalculated to equivalent (ecologically effective) surfaces. This means that certain features can count towards several aspects multiple times and are therefore more important since they contribute to the calculated GYF for different input areas.
The input parameters also contribute to biodiversity (B), social value (S), and climate adaptation (C).
For more information and detailed description of all input parameters, see references above.
Table 1 Input data for Stockholm Green calculation module
|Applicable to district||Unit||Explanations|
|Total Land Area of Plot||m2||This is the surface area for the district.|
|Unsupported ground greenery||m2||CF. Contribute to B, S and C.|
|Plant bed (>800 mm)||m2||CF. Contribute to B, S and C.|
|Plant bed (600 – 800 mm)||m2||CF. Contribute to B, S and C.|
|Plant bed (200 – 600 mm)||m2||CF. Contribute to B, S and C.|
|Green roof (>300 mm)||m2||CF. Contribute to B, S and C.|
|Green roof (50 – 300 mm)||m2||CF. Contribute to B, S and C.|
|Greenery on walls||m2||CF. Contribute to B, S and C.|
|Balcony boxes||m2||CF. Contribute to B, S and C.|
|Water surface permanent||m2||CF. Contribute to B, S and C.|
|Open hard surfaces that allow water to get through||m2||CF. Contribute to B, S and C.|
|Gravel and sand||m2||CF. Contribute to S and C.|
|Concrete slabs with joints||m2||CF. Contribute to S and C.|
|Diversity in the field layer||m2||AF. Contribute to B.|
|Natural species selection||m2||AF. Contribute to B.|
|Diversity on thin sedum roofs||m2||AF. Contribute to B.|
|Integrated balcony boxes with climbing plants||m2||AF. Contribute to B.|
|Butterfly restaurants||m2||AF. Contribute to B.|
|General bushes||m2||AF. Contribute to B.|
|Berry bushes||m2||AF. Contribute to B.|
|Large trees||–||AF. Contribute to B. Large trees (trunk >30 cm).|
|Medium large trees||–||AF. Contribute to B. Medium large trees (trunk 20-30 cm).|
|Small trees||–||AF. Contribute to B. Small trees (trunk 16-20 cm).|
|Oaks||–||AF. Contribute to B. Oak trees (Quercus robur).|
|Fruit trees||–||AF. Contribute to B.|
|Fauna depots||–||AF. Contribute to B.|
|Beetle feeders||–||AF. Contribute to B.|
|Bird feeders||–||AF. Contribute to B.|
|Biologically accessible permanent water||m2||AF. Contribute to B.|
|Dry areas with plants that temporarily fill with rain water||m2||AF. Contribute to B.|
|Delay of rainwater in ponds||m2||AF. Contribute to B.|
|Delay of rainwater in underground percolation systems||m2||AF. Contribute to B.|
|Runoff from impermeable surfaces to surfaces with plants||m2||AF. Contribute to B.|
|Grass area – games||m2||AF. Contribute to S. Grass area usable for ball games and playing.|
|Gardening areas in yards||m2||AF. Contribute to S.|
|Balconies and terraces prepared for growing||m2||AF. Contribute to S.|
|Shared roof terraces||m2||AF. Contribute to S.|
|Visible green roofs||m2||AF. Contribute to S.|
|Floral arrangements||m2||AF. Contribute to S.|
|Experiential values of bushes||m2||AF. Contribute to S.|
|Berry bushes with edible fruits||m2||AF. Contribute to S.|
|Trees experiential value||–||AF. Contribute to S.|
|Fruit trees and blooming trees||–||AF. Contribute to S.|
|Green surrounded||m2||AF. Contribute to S. Pergolas, paths surrounded by leaves and other greenery|
|Bird feeders – experiential value||–||AF. Contribute to S.|
|Water surfaces||m2||AF. Contribute to S.|
|Biologically accessible water – experimental value||m2||AF. Contribute to S.|
|Fountains, circulations systems, etc.||–||AF. Contribute to S.|
|Trees leafy shading||–||AF. Contribute to C. Trees with leafy shade over play areas, etc.|
|Shade from leaf cover||m2||AF. Contribute to C. Pergolas, green corridors etc.|
|Evening out of temp||m2||AF. Contribute to C. Green roofs, ground greenery.|
|Water collection during dry periods||m2||AF. Contribute to C.|
|Collected rainwater for watering – climate impact||m2||AF. Contribute to C.|
|Fountains etc. – cooling effect||–||AF. Contribute to C.|
Information for programmers
For more information about the Stockholm Green module for programmers, turn to link >>.