Description

Accessibility is an indicator describing the quality of a particular entity of being reached. In this case accessibility is measured referring to green spaces and their walking distance from residential areas. Concluding this indicator is measuring the walking distance between a certain point (residential building) and the nearest green space. However, Accessibility gives information on the residential a building itself, and thus the spatial distribution of green spaces in the city.

Accessibility can be measured in several ways. We can distinguish different methodologies based on what types of NBS are taken into account: only green spaces above a certain area or we can also consider linear and spot-like NBSs too. On the other hand, we can also calculate accessibility based on the radius of certain NBSs or based on the walking distance between two points. 

Scale as linked to D2.2 framework

• Neighborhood

Data source [ link to data framework]

• Municipality databases
• Open sources like Open Street Map
• Proprietary sources like Google, TomTom etc.

Data needs

• Topographic base and vectoral database of the analysed area (including green spaces / NBSs)
• Optional: walking distance based on road network.

Expected Outputs

• unit is m/minutes.
• Map representing either distance or walking distance in time. 

Calculation methods

• The travel distance model measures the minimum travel distance between each location of origin and the nearest destination, and can be expressed as (Talen and Anselin 1998):
• 

Links and references

• Freeman, Linton (1977). "A set of measures of centrality based on betweenness". Sociometry.40: 35–41. doi:10.2307/3033543.
• BARABÁSI, Albert-László. Network science book. Boston, MA: Center for Complex Network, Northeastern University. Available online at: http://barabasi. com/networksciencebook, 2014.
• Swyngedouw, E. and Kaika, M. (2003) The Environment of the City… or the Urbanization of Nature, in A Companion to the City (eds G. Bridge and S. Watson), Blackwell Publishing Ltd, Oxford, UK. doi: 10.1002/9780470693414.ch47
• Andrés Duany, Elizabeth Plater-Zyberk, and Jeff Speck: Suburban Nation: The Rise of Sprawl and the Decline of the American Dream, Farrar, Straus and Giroux, 2010
• E Talen, L Anselin (1998): Assessing Spatial Equity: An Evaluation of Measures of Accessibility to Public Playgrounds: https://doi.org/10.1068/a30059