The changing landscape of Canadian metropolitan areas, 1971 to 2011
Ottawa - The built-up area of Canada's census metropolitan areas (CMAs) more than doubled in size from 1971 to 2011. A new study, "The changing landscape of Canadian metropolitan areas," released today in Human Activity and the Environment, found that built-up areas increased 157% from 5,651 square kilometres (km2) in 1971 to 14,546 km2 in 2011.
Among large census metropolitan areas, Edmonton and OttawaGatineau (Ontario part) have the highest growth rates for built-up area
In 2011, the Toronto CMA had the largest built-up area in the country, with 2,184 km2 of roads and settled areas. Other large CMAs included Montréal, ranked second with 1,571 km2, Edmonton (1,094 km2), Vancouver (995 km2), Calgary (700 km2) and OttawaGatineau (Ontario part) (635 km2). Built-up areas are characterized by a high percentage of impervious surfaces such as roadways, parking lots and roof tops.
From 1971 to 2011, built-up area increased most in Toronto (+1,189 km2), Montréal (+816 km2), Edmonton (+752 km2), Vancouver (+503 km2), Calgary (+427 km2) and OttawaGatineau (Ontario part) (+417 km2).
Of these CMAs, Edmonton (+220%) and OttawaGatineau (Ontario part) (+191%) had the highest built-up area growth rates from 1971 to 2011.
Built-up area in mid-sized and smaller CMAs also expanded considerably: Halifax (+319 km2), Québec (+292 km2), OttawaGatineau (Quebec part) (+261 km2) and London (+247 km2). Among them, OttawaGatineau (Quebec part) had the highest growth rate, with built-up area increasing 391% from 1971 to 2011.
The growth rate of built-up areas was also high in several newer CMAs, such as Kelowna, AbbotsfordMission and Barrie, which did not meet the criteria to be considered CMAs in 1971.
In 2011, the CMAs with the highest population density were Toronto (3,368 persons/km2), Montréal (3,356 persons/km2), Vancouver (3,100 persons/km2) and Calgary (2,685 persons/km2), indicating that these CMAs had more compact forms of development.
Average CMA population density dropped from approximately 3,460 persons/km2 in 1971 to nearly 2,110 persons/km2 in 2001, but then increased slightly to 2,250 persons/km2 in 2011.
From 2001 to 2011, population density increased most in Toronto (+411 persons/km2 or +14%), Vancouver (+327 persons/km2 or +12%), Calgary (+290 persons/km2 or +12%), Barrie (+258 persons/km2 or +19%), Oshawa (+237 persons/km2 or +13%) and Edmonton (+226 persons/km2 or +16%).
Settled area expansion on arable, and natural and semi-natural land
This study also examined changes in the cover and use of the land surrounding CMAs, an area called the 'CMAecosystem' (CMAE). CMAEs that had a large amount of arable land in 2011 were mainly located in the Prairies and in southern Ontario and Quebec. CMAEs in these areas were also likely to have arable land make up a high proportion of their total land area and have correspondingly lower proportions of natural and semi-natural land.
From 1971 to 2011, relatively equal proportions of arable and natural and semi-natural land were lost to settled area, though the split varied by metropolitan area.
CMAEs with the largest increases in settled area on arable land include those in the Golden Horseshoefor example, the Toronto CMAE with 961 km2. Others include Montréal (+448 km2), Edmonton (+402 km2), OttawaGatineau (Ontario part) (+295 km2), London (+256 km2) and Calgary (+214 km2).
Most growth in settled area in Windsor (85% of growth, or an increase of 134 km2), London (73% or +256 km2), Hamilton (72% or +487 km2), Edmonton (70% or +402 km2) and Saskatoon (69% or +108 km2) occurred on arable land.
CMAEs with the largest increases in settled area on natural and semi-natural land include Montréal (+462 km2), Toronto (+448 km2), Halifax (+297 km2) and Vancouver (+296 km2). Most growth in settled area in Greater Sudbury (87% of growth, or an increase of 259 km2), Thunder Bay (87% or +130 km2), Halifax (86% or +297 km2) and St. John's (83% or +91 km2) occurred on natural or semi-natural land. Most natural and semi-natural land lost to settled area from 1971 to 2011 was forest land or natural land for pasture.
For many CMAEs in southern Ontario, settled area expansion occurred largely on the highest quality farmland, also known as dependable agricultural land. For example, in the CMAEs of Toronto, London, St. CatharinesNiagara and Windsor, 85% of the land converted to settled area from 1971 to 2011 occurred on Class 1 to 3 agricultural land, accounting for 9% of the stock of dependable agricultural land in these CMAEs.