(Montreal) Researchers at Concordia University say they’ve found an “almost always effective” way to curb urban sprawl, particularly in large cities.
Posted at 11:50am
Elo Gauthier Lamothe The Canadian Press
According to their study, the use of “green belts” on the outskirts of metropolitan areas could limit this environmentally harmful phenomenon. These belts are protected areas such as forests or agricultural land surrounding a city or region where real estate development is severely restricted or even banned.
According to Parnian Pourtaherian, lead author of the report published in the journal Landscape and Urban Planning, these spaces would prevent the often disorderly expansion of suburbs and economic sectors.
Using open-source data, researchers tracked the urban sprawl of 60 European cities between 2006 and 2015, half of which had green belts. These were divided into four categories: very large cities (2.5 million inhabitants or more), large cities (more than 1 million inhabitants), medium-sized cities (500,000 to 1 million inhabitants) and medium-sized cities (96,000 to 500,000 inhabitants). .
According to the study, 90% of the cities with a green belt had seen a decrease in urban sprawl in the given time period. Conversely, only 36% of the other cities saw such a decline.
“We found large differences in the effectiveness of the green belt in small, medium and large cities, but the difference in the relative changes in urban sprawl was more pronounced in large cities,” the researcher specifies.
Parnian Pourtaherian, who has a master’s degree in natural sciences from Concordia University’s Department of Geography, Urban Planning and the Environment, argues that this method could also be used across Canada.
“Ottawa and Toronto both have green belts, and Vancouver has a ‘green zone’ that acts as such. On the other hand, Montreal doesn’t have a real green belt yet, but it badly needs one,” she says.
Efficient…so well regulated
For Jochen Jaeger, a professor in the Department of Geography, Urban Planning and the Environment at Concordia University, green belts are almost always effective when they are well managed. Their performance can be affected if they’re not properly protected, the researcher points out, or if they’re too small or narrow.
“Some developers and politicians are using the housing crisis argument to expand large development areas and allow additional low-density urban growth or even repeal existing protection laws. They’re also employing a “salami tactic” to destroy the green belt, arguing that every chunk lost is just a “pointless” loss – until there’s nothing left,” laments the study’s co-signatory.
These green belts are a major obstacle to urban sprawl, which consists of an increase in urban areas in a given area. This phenomenon is characterized by low compaction and a large area, often only accessible by road.
This suburban spread seems to have coincided with population growth, but its spread takes residents away from the services offered in the major centers and further threatens the fauna and flora on the outskirts of the cities.
“Limiting urban sprawl is critical as it leads to loss of green space and wildlife habitat, as well as reduced ecosystem resilience due to habitat fragmentation, declining wildlife populations and local species extinction,” says Dr. Hunter.
These impacts would be exacerbated by the climate crisis, the researcher adds, leading to higher spending on transport infrastructure, electricity, water supply and sanitation. Urban sprawl is also associated with increased use of fossil fuels for transportation and the loss of fertile agricultural land.
“By avoiding the expansion of sparsely populated urban areas into natural spaces, the benefits of those spaces – including better air and water quality – are preserved, which the present generation can then pass on to future generations,” he concludes.