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Delineating population clusters. Applying grid methods Niek van Leeuwen Statistics Netherlands nlwe@cbs.nl. Presentation. Occasion Methods Population cluster map Grid methods Results Further research. Occasion.
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Delineating population clusters Applying grid methods Niek van LeeuwenStatistics Netherlands nlwe@cbs.nl
Presentation • Occasion • Methods • Population cluster map • Grid methods • Results • Further research
Occasion • EU Census 2001, population cluster map, based on land use map 2000, production 2005 • Land use map 2003 published in 2006 • More recent statistics on population clusters
Occasion • Two methods • Polygons • network of paved roads and address points • Grid method • delineating by grids only
Methods • comparing polygon and grid methods: data 2001 • polygon: • - population cluster map • grid: • - number of dwellings per grid cell • - proximity factor • calibration set: • - Combination of polygons and grid cells with totalized number of dwellings and proximity factors per cell.
Methodspopulation cluster map (1) • - morphological delineated area • mainly groups of residential houses • recognizable street pattern (no ribbon development) • form one cluster when: • separated < 200m separated > 200m but connected by bridge • minimum number of dwellings
MethodsGrid (1) • total number of dwellings per grid • dwellings from housing register with addresses • addresses provided with coordinates • proximity factor • - each cell calculated a proximity factor
Results, grid6.76 million dwellings, 532 thousand grids (100m)
Results, Calibration set Grid cells combined with residential areas (1)
Results, Calibration setGrid cellscombined with residential areas (2)
MethodsGrid (2) Proximity factor R =radius in number of cells N = number of cells involved 100m x 100m grid cell Radius R N 1000m 10 317 500m 5 81 200m 2 13
Dwellingsproximity selectionradius 1000m, threshold 200 dwellings / km2
Dwellingsproximity selectionradius 200m, threshold 400 dwellings / km2
ResultsArea “Het Westland”, SW of The HagueDwellings per 100m grid
ResultsArea “Het Westland”Proximity; radius 1000m, threshold 200 dwellings / km2
ResultsArea “Het Westland”Proximity; radius 200m, threshold value 400 dwellings / km2
River basin areaNear Gorinchemresidential and other areas in population cluster polygons
River basin areaNear Gorinchemproximity radius 1000m, threshold 200 dwellings / km2
River basin area Near Gorinchemproximity radius 200m, threshold 400 dwellings / km2
Concluding • Delineating residential area by total number of dwellings is not sufficient • Proximity is the measure
Future research • Grid method • calibration: effects of selection on number of residential areas and statistics. • Adding non dwelling addresses Vector method - delineating residential areas from National road file and address points