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Defining urban areas,some case studies in Finland
Nordic Forum for Geostatistics Sinikka
LaurilaStatistics Finland26.3.2004
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• Definitions from ...
• National Land Survey
• Finnish Environment Institute
• Technical Research Center of Finland
• Statistics Finland
• Conclusions - some issues in developing
  delineation

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National Land Survey
- in large scale mapsbase map, land use
mapdelineation based on satellite maps,
built-up-areas and otheravailable map data -
in small scale mapsfrom scale 1250 000
onwards delineation based on building coordinates
method grid-buffer method (grid size
25mx25m)localities, when at least 180
inhabitants - no nomenclature (codes or names)
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National Land Survey...
- functionality mainly cartographic elements or
delineating tightly populated areas - no
statistics included
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Finnish Environment Institute
- grid based method - data aggregated in the
center of a 250m x 250m grid - preconditions
the grid contains at least 50 buildings and the
aggregate area of the buildings is at least 1
500 square meters - the part of water areas is
added to grids - update interval 3 to 5 years
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Finnish Environment Institute ...
- The System for Monitoring the communities -
development of community indicators comparable in
space and time using grid data- monitoring
the inside structure and structural changes in
locality areas - statistical grid data
(125mx125m) from 3 km buffers of the locality
centers - the system is used by 13 local offices

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Settlement Structure of the Bothnian Arc
Area
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Source Finnish Environment Center, 2003
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A Closer Zooming to Border Between Two Countries
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Source Finnish Environment Center, 2003
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SO
Finnish datasets were adapted to Swedish
coordinate system
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Results
The population density of densely populated
areas in Sweden is almost double compared to
Finland
70 of the population live on the 10 km wide
coastal zone
Source Finnish Environment Center, 2003
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Technical Research Center of Finland
- based on building coordinates- building
coordinates are converted to triangles- the size
of the triangle page is flexible (for instance
200 m)- triangles are converted to areas, which
are buffered by 50 m - grid data, point data
(population, buildings, employment etc.) - a very
accurate delineation
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Technical Research Center of Finland ...
- monitoring and describing communities and
regional structures- tools provided (mainly
usable in MapInfo/Vertical Mapper) monitoring
built-up areas commuting urban and rural
areas traffic streames in commuting urban
areas - aimed for regional planners
researchers decision making procesesses in
regional planning
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and Statistics Finland
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Background
Localities
5.2 mil. inhabitants 1.3 mil. buildings 305 000
km2 land area
Built up areas
Uninhabited
1 4 0 0 km
Lakes
About 17 people per km2 Share of total land area
for localities about 2.5
650 km
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Requirementsand bases for the delineation method
The definition of localities

• At least 200 residents
• Distance between buildings max 200 meters
• Continuous area
• Do not restrict any administrative area

Buildings

• Location x,y
• The use of building
• The number of residents

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The development of the delineation methodTwo
different methods

• Buffering points

• Gridding and buffering

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Spatial parametersDifferent grid sizes
100 x 100 meter gridnet
Building point
100 x 100 meter grid
75 x 75 meter grid
50 x 50 meter grid
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Spatial parametersDifferent buffer Zones
100 x 100 meter gridnet
Building point
100 x 100 meter grid and 50 meter buffer-zone
75 x75 meter grid and 50 meter buffer-zone
50 x 50 meter grid and 75 meter buffer-zone
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The Grid- and buffer- method Clusters of
buildings

• Buildings
• Two ArcInfo Grids (raster surface)
• Grid A, all buildings, value 50
• Grid B, other than residential buildings, value
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• The final model, grid A B, values 50 and 75

Residential buildings
Other buildings
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The Grid- and buffer- methodThe Clusters of
buildings

• Grid to polygons
• Merge the polygons by 50/75 meter buffer zone

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The Grid- and buffer- methodThe preform of
localities and their satellites

• Select the areas with at least 200 residents
• Buffer zone with 100 meters
• Assemble the preform of localities and they
  satellites in one coverage

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The Grid- and buffer- methodThe final localities

• Merge polygons together with 100 meters buffer
  zone
• Resize the the buffer zone back to original (-100
  meters)

1057 Arpela
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The Grid- and buffer- methodBy-products

• Holes or gaps
• Built-up areas

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Evaluations of the adopted method

• Effect to the working process
• Quantity of data

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The evaluation of the adopted methodEvaluating
the results
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Localities 2000
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The time series 1990,1995 and 2000 The Oulu
region
1990
2000
The density of population 812 as./km²
The density of population 906 as./km²
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Conclusions
- present definition provides aggregate locality
statistics- unable to describe the structure or
deveplopment (functionality) in localities
(urban areas)- factors that determine urban
areas besides population or buildings
employment commuting municipal infrastructure
supply of services ...
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Thank You !