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A 1 Defining urban areas, some case studies in Finland Nordic Forum for Geostatistics Sinikka Laurila Statistics Finland 26.3.2004 Slide 2 A 2 Definitions from... National Land Survey Finnish Environment Institute Technical Research Center of Finland Statistics Finland Conclusions - some issues in developing delineation Slide 3 A 3 National Land Survey - in large scale maps: base map, land use map delineation based on satellite maps, built-up-areas and other available map data - in small scale maps: from scale 1:250 000 onwards delineation based on building coordinates method grid-buffer method (grid size 25mx25m) localities, when at least 180 inhabitants - no nomenclature (codes or names) Slide 4 A 4 Slide 5 A 5 Slide 6 A 6 National Land Survey... - functionality: mainly cartographic elements or delineating tightly populated areas - no statistics included Slide 7 A 7 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 Slide 8 A 8 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 Slide 9 A 9 Slide 10 A 10 Settlement Structure of the Bothnian Arc Area Slide 11 A 11 Source: Finnish Environment Center, 2003 Slide 12 A 12 A Closer Zooming to Border Between Two Countries Slide 13 A 13 Source: Finnish Environment Center, 2003 Slide 14 A 14 SO: Finnish datasets were adapted to Swedish coordinate system Slide 15 A 15 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 Slide 16 A 16 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 Slide 17 A 17 Slide 18 A 18 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 Slide 19 A 19 Slide 20 A 20 Slide 21 A 21 and Statistics Finland Slide 22 A 22 Background 1 4 0 km 650 km Localities Built up areas Uninhabited Lakes 5.2 mil. inhabitants 1.3 mil. buildings 305 000 km2 land area About 17 people per km2 Share of total land area for localities about 2.5 Slide 23 A 23 Requirements and bases for the delineation method Buildings The definition of localities At least 200 residents Distance between buildings max 200 meters Continuous area Do not restrict any administrative area Location x,y The use of building The number of residents Slide 24 A 24 The development of the delineation method Two different methods Buffering points Gridding and buffering Slide 25 A 25 Spatial parameters Different grid sizes 100 x 100 meter gridnet 100 x 100 meter grid Building point 75 x 75 meter grid 50 x 50 meter grid Slide 26 A 26 Spatial parameters Different buffer Zones 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 100 x 100 meter gridnet Building point Slide 27 A 27 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 25 The final model, grid A + B, values 50 and 75 Other buildings Residential buildings Slide 28 A 28 The Grid- and buffer- method The Clusters of buildings Grid to polygons Merge the polygons by 50/75 meter buffer zone Slide 29 A 29 The Grid- and buffer- method The 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 Slide 30 A 30 The Grid- and buffer- method The final localities Merge polygons together with 100 meters buffer zone Resize the the buffer zone back to original (-100 meters) 1057 Arpela Slide 31 A 31 The Grid- and buffer- method By-products Holes or gaps Built-up areas Slide 32 A 32 Evaluations of the adopted method Effect to the working process Quantity of data Slide 33 A 33 The evaluation of the adopted method Evaluating the results Slide 34 A 34 Localities 2000 Slide 35 A 35 The time series: 1990,1995 and 2000 The Oulu region 19902000 The density of population 812 as./kmThe density of population 906 as./km Slide 36 A 36 Slide 37 A 37 Slide 38 A 38 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... Slide 39 A 39 Thank You !