How the science of cities can help European policy makers ... _urbanisation... · How the science...
Transcript of How the science of cities can help European policy makers ... _urbanisation... · How the science...
Regional & Urban Policy
How the science of cities can help European policy
makers: new analysis and perspectives
By Lewis Dijkstra, PhD
Deputy Head of the Economic Analysis Unit,
DG Regional and Urban Policy
European Commission
Regional & Urban Policy
Overview
• Data revolution
• Defining cities
• New analysis and links to the urban sustainable development goal indicators
• Density
• Land use changes
• Green space
• Public transport
Regional & Urban Policy
A data revolution
• More micro data (population register, business register, patents)
• More geo-coded data (building register, census…)
• More remote sensing data (water, green, imperviousness, buildings…)
• More big data (smart phones, geotagged pictures, messages…)
Regional & Urban Policy
Copernicus Urban Atlas
• Thematic classes based on CORINE Land Cover nomenclature
• But more specific for built-up areas, and less specific outside urban areas
• Geometric resolution of 1:10,000
• Minimum mapping unit of 0.25 ha in urban areas, 1 ha in other areas
• Imagery reference year: 2006 and 2012
Regional & Urban Policy
What makes a city?
• Buildings, mass, proximity
• People, density, size
• Exchange, intensity, distance
• Functions, specialised, variety
• Political
• Economically linked
• Labour market, commuting zone
Regional & Urban Policy
Population distribution within a city
1. To find out IF a municipality contains a city
2. To define an 'urban centre'
3. To measure access to transport, green space…
4. To measure weighted density instead of average density
5. To measure exposure to air quality
Regional & Urban Policy
EU-OECD city and commuting zone definition in three steps
1. Define an urban centre of 50 000 or more
2. Define a city based on this urban centre (consisting of one or more municipalities)
3. Define a commuting zone based on this city (including check for polycentric cities)
IMPORTANT! Cities are selected based on the population of their centre, not total population
Regional & Urban Policy
Three grid concepts
1. Urban centres = contiguous (excluding diagonals) cells with a density of at least 1500 inhab/km2 and a minimum of 50 000 inhabitants (after gaps filled with majority rule)
2. Urban clusters = contiguous (including diagonals) cells with a density of at least 300 inhab/km2 and a minimum of 5 000 inhabitants (no gap filling)
3. Rural grid cells = cells outside urban clusters
Regional & Urban Policy
Three degrees of urbanisation Three grid concepts (Cork, IE)
Three types of municipalities
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Three types of municipalities
Cities > 50% pop. in urban centres
Towns and suburbs
> 50% pop. in urban clusters
< 50% pop. in urban centres
Rural area > 50% pop. in rural grid cells
Urban areas = Cities + Towns and Suburbs
Regional & Urban Policy
Density drops away from the centre
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Popu
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Population density profile of selected mid-sized European capital cities, 2006
Distance from city centre (Km) Source: Batista e Silva, F. et al. (2012)
Wien
Lisbon
Budapest
Brussels
Stockholm
Dublin Amsterdam
Regional & Urban Policy
Share of built-up area drops away from the centre
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Distance to the city centre
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Regional & Urban Policy
Share of built-up area drops away from the centre (cumulative)
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Maximum distance to the centre
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Regional & Urban Policy
Density or land use indicators
• Target 11.b holistic disaster risk management
• Population density measured over continuous urban footprint
• Target 11.3 sustainable urbanization (& 11.a)
• Ratio of land consumption rate to population growth rate at comparable scale
• Problems
• Urban footprint or building footprint
• What is land consumption?
• What scale?
Regional & Urban Policy
Proposal land use efficiency indicator
• Measure built-up area (building footprint) per inhabitant based on GHSL for
• Cities following the EU-OECD definition and
• Commuting zone (if commuting is available) or
• Suburbs following degree of urbanisation or
• A buffer based on population size of a city
• Monitor the changes in built-up area per capita over time (land use efficiency)
• Cities with a high efficiency can reduce it, cities with low efficiency should increase it.
Regional & Urban Policy
Measuring access to public transport: input data
• Location of all public transport stops
• Timetables of services: 2 groups:
• bus and tram
• train and metro
• Population per building block based on:
• detailed population grids
• census tracts
• neighbourhood statistics
• plus disaggregation using land use data and/or imperviousness if needed
Regional & Urban Policy
Spatial distribution of population matters
No location awareness: assuming uniform population density throughout the city
High-resolution spatial distribution of population: Opportunities for new indicators
Regional & Urban Policy
Frequency of departures
• Average stops an hour from 6:00 to 20:00 on a normal week day
Very high
More than ten departures an hour for both medium- and high-speed modes
High More than ten departures an hour for one mode, but not both
Medium
Between four and ten departures an hour on one or both modes, but no access to more than ten departures and hour
Low less than four departures an hour for one or both modes, but no access to more than four departures an hour
Null No access within walking distance
Regional & Urban Policy
Typology of frequency classes
Very high Access to more than ten departures an hour for both medium- and high-speed modes
High Access to more than ten departures an hour for one mode, but not both
Medium Access to between four and ten departures an hour on one or both modes, but no access to more than ten departures and hour
Low less than four departures an hour for one or both modes, but no access to more than four departures an hour
Null No access within walking distance
Regional & Urban Policy
Stockholm: areas and population by access to public transport and its frequency
844,000 1,135,000 1,542,000 2,042,000 inh. inh. inh. inh.
Regional & Urban Policy
Access to public transport in Brussels
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Distance to the city centre in km
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Access to a
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frequency of
Regional & Urban Policy
Target 11.2 Public transport
• Share of people living within 0.5 km of public transit [running at least every 20 minutes] in cities with more than 500,000 inhabitants
• Specify the city definition to be used
• Km of high capacity (BRT, light rail, metro) public transport per person for cities with more than 500,000 inhabitants
• Why not measure access to high capacity public transport?
Regional & Urban Policy
Green spaces in Brussels, 2012
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Distance to city centre in km
forests
agriculture and natural areas
sports and leisure
green urban areas
Regional & Urban Policy
Access to green spaces by size
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Maximum distance to the city centre in km
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Access according to the size of green space
Regional & Urban Policy
Target 11.7 Green and public space
• Area of public space as a % of total city space
• Share of residents within 0.5 km of accessible green and public space
• Accessible is extremely difficult to determine
• Public space: roads, sidewalks, squares?
• Proposal: share of residents with
• Almost no open space in a buffer of 0.5 km
• No green space of at least x m2 within 0.5 km
• This avoids the problem of measuring access, but it will be a subset of the population with no access
Regional & Urban Policy
Conclusion
• Data revolution is in full swing, but we need
• a universe of cities using a single methodology
• Understand population distribution within cities
• Be aware of the modifiable area unit problem:
• Use uniform building blocks (like grid cells)
• Use population with access rather than area share
• When using area shares, use a grid definition, not an administrative one
• Take full advantage of new continuous, high resolution data sets (vs coarse and binary data)
Regional & Urban Policy
More information
• EU-OECD City definition
• http://ec.europa.eu/regional_policy/sources/docgener/focus/2012_01_city.pdf
• New degree of urbanisation
• http://ec.europa.eu/regional_policy/sources/docgener/work/2014_01_new_urban.pdf