Trees are good contributors in urban landscaping. However, trees can also cause negative influence at different levels to its surroundings. The uncontrollable growth of the canopy could block sunlight from nearby houses. And during windstorm, fallen trees could cause huge damage to traffic and people’s property.
The current management of the city’s public trees was fully relying on residents’ damage reports, which means actions have only been taken after the damage (Street Tree By-law NO.5985, 1992). According to the historical record, only 30% of the potential problems of the trees were reported before the damage (VanConnect, 2019). This method is ineffective and inefficient because of three major reasons. Firstly, many people that are lack of professional training cannot precisely assess the possibility of tree fall, so they do not recognize the danger before the actual damage. Thus, they will not report the issue. Secondly, many people want to report the issue but become unable to report. Because they are confused by the complexness of the online report system, and their phone call can never be reached due to the frequently busy emergency line. Finally, it takes a long time for the city to respond to an issue.
Therefore, I decide to analyze the potential negative influence of urban trees in advance. And this project will provide an idea on how to prevent the negative influence of city trees in advance by imitating the real-world tree shadow coverage on houses and tree falling situation in ArcGIS. The objective of this project is to find the potential canopy shade coverage on nearby houses, and predict the potential falling direction and damage areas when a windstorm comes. The study will be conducted on one neighbourhood with high volume of street trees: Dunbar north region around Balaclava Park.