Sunday, July 22, 2012
There has been a lot of talk lately about distribution of vegetation in urban areas. The changes are so stark that we can identify low income communities from satellite photos just on the basis of tree cover. This new study illustrates this phenomenon examining Montreal.
Spatial distribution of vegetation in Montreal: An uneven distribution or environmental inequity? By Thi-Thanh-Hien Pham, Philippe Apparicio, Anne-Marie Séguin, Shawn Landry, Martin Gagnon in Landscape and Urban Planning (2012)
Growing evidence is showing that across North American cities, underprivileged populations and racial and/or visible groups have disproportionally less access to vegetation than affluent groups, raising concerns of environmental inequity. This study aims to verify whether in Montreal (Canada) there is environmental inequity resulting from variations in urban vegetation for low-income people and visible minorities. More specifically, various vegetation indicators were extracted from very-high-resolution satellite images, including the proportion of city blocks, streets, alleys and backyards covered by total vegetation and trees/shrubs. Socio-demographic variables were obtained from 2006 Canada Census and rescaled to the city block level, by using a population-based weighing method. Statistical analysis indicates that there are disparities in the distribution of vegetation in Montreal which disfavour low-income people and, to a lesser extent, visible minorities. Disparities are also more pronounced on public land (streets, alleys) than on private land (backyards). Income is a major factor but cannot fully explain inequities among visible minorities. Notwithstanding the weak extent of such disparities, those vulnerable communities might need a better access to ecological services provided by vegetation, notably such as heat island mitigation. Compensatory equity needs to be addressed and our findings call for authorities to reconsider greening budgetary allocation and practices, especially in the most deprived neighbourhoods of the city.