Delimitation of urban settlements in Norway Margrete Steinnes, SSB

Todays delimitation of urban areas Adjusting the delimitation based on landuse maps Testing the Nordic definition

Definition used today A hub of buildings shall be registered as an urban settlement if it is inhabited by at least 200 persons (60 - 70 dwellings). The distance between the buildings shall normally not exceed 50 metres. Deviations are allowed for areas that cannot/are not to be occupied, for example parks, sports facilities, industrial areas or natural barriers such as rivers or arable land. Also included are agglomerations that naturally belong to the urban settlement with up to a distance of 400 meters from the centre of the urban settlement.

Todays method Method developed in 1999: Buildings (as points) are buffered with the radius of the ground floor + 25 meters. Buildingstypes that normally occupy larger areas are buffered with 100 meters (schools, hospitals, churches, industry e.g.) Sportsfacilities are included as buffered points Inhabitants counted within polygons, 200 + chosen Negative buffer of 75 meters

Method

Result

Problems ”Bubble-shaped” outline More accurate data is available

Problems Undeveloped areas make up 20-30 per cent even of the largest cities

Problems Some elements take up to much space (sports facilities, large buildings) Built-up elements with no buildings are not represented (parks, industrial areas)

New landuse map Better quality maps are availble Buildings outlines Properties as polygons Roads as polygons ++ Land resource map covers the whole country Using exsisting digital maps GIS-system; automatic delimitation, classification and placing in hierarcy Main principle: Use the highest quality data sources available, but use the next best quality where no optimal data source exists

Built-up areas, landuse map

Built-up areas, landuse map Bygningene ligger delvis innenfor og delvis utenfor det bebygde arealet. Utnyttingsgraden er høy nok begge steder. Hele eiendommen velges som arealfigur. Spesialtilfelle: For boligeiendommer som er mindre enn 1 dekar regnes hele eiendommen som bebygd. N Bygningen ligger helt utenfor bebygd areal. Hele eiendommen velges som arealfigur. Utnyttingsgraden på eiendommen er for lav. Det bufres rundt bygget.

Hierarki

Adjusting the boundaries of urban settlements Keeping todays definition Keeping the distance citerias (50m, 200m) Total number of inhabitants stay the same Removing the non built-up areas at the edge of the settlement

Method for adjusting boundaries

Testing the Nordic definition Tested in 2004 (http://www.ssb.no/natur-og-miljo/artikler-og-publikasjoner/utproving-av-nordisk-tettstedsdefinisjon-i-norge) Main criterias: 200 inhabitants, less than 200 meters distance between buildings Method: Buildings (as points) are buffered with the radius of the ground floor + 100 meter. Inhabitants counted within polygons, 200 + chosen Negative buffer of 75 meters

Results Number of urban settlements: from 932 to 1493 (60 % increase) Total area increases by 57 % Population increases by 7 % Long, narrow and continuos urban settlements along valleys and fjords

Examples

Conclusion Too much rural land is included Existing operationalized definition is more in line with the Nordic definition than a strict 200 meter distance criteria.