delineating population clusters

Delineating population clustersApplying 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

Two methods

- Polygons

network of paved roads and address points

- Grid method

delineating by grids only

Occasion

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

Methodspopulation cluster map (2)

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 set

Grid cells combined with residential areas (2)

MethodsGrid (2) Proximity factor

N

Area

RCIRCLEingridfocalsumoutgrid

1

),,(

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 selection radius 1000m, threshold 200 dwellings / km2

Dwellingsproximity selection radius 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 Gorinchemdwellings per 100m grid

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

Thank you for your attention