Outline
- Abstract
- Keywords
- Introduction
- Study Area
- Methods
- Results
- Discussion
- Conclusions
- Acknowledgements
- References
رئوس مطالب
- چکیده
- کلیدواژه ها
- مقدمه
- ناحیه مورد مطالعه
- متدها
- نتایج
- بحث
- نتیجه گیری ها
Abstract
One of the fastest growing cities in India, Bangalore is facing challenges of urban microclimate change and increasing levels of air pollution. This paper assesses the impact of street trees in mitigating these issues. At twenty locations in the city, we compare segments of roads with and without trees, assessing the relationship of environmental differences with the presence or absence of street tree cover. Street segments with trees had on average lower temperature, humidity and pollution, with afternoon ambient air temperatures lower by as much as 5.6 °C, road surface temperatures lower by as much as 27.5 °C, and SO2 levels reduced by as much as 65%. Suspended Particulate Matter (SPM) levels were very high on exposed roads, with 50% of the roads showing levels approaching twice the permissible limits, while 80% of the street segments with trees had SPM levels within prescribed limits. In an era of exacerbated urbanization and climate change, tropical cities such as Bangalore will have to face some of the worst impacts including air pollution and microclimatic alterations. The information generated in this study can help appropriately assess the environmental benefits provided by urban trees, providing useful inputs for urban planners.
Keywords: Climate change - Sustainability - Tree plantation - Urban forests - Urban heat islandsConclusions
This study provides initial, exploratory insights into the possible environmental benefits of street trees in reducing air temperature, humidity and air pollution in tropical developing cities, where insufficient information is currently available. Results indicate that ambient air temperature, road surface temperature humidity and air pollution are lower in road segments with tree cover in Bangalore, although the small sample size and lack of information on wind speed are potentially confounding factors that may influence our results. While this study provides a preliminary exploration of some of these issues, more extended, in-depth research is required to focus the attention of planners on the role of urban greenery in sustainable city management, a role that has been largely ignored in many developing country cities (Kuruneri-Chitepo and Shackleton, 2011). Tropical cities like Bangalore, where the impacts of warming and air pollution may be especially severe, could benefit from programs of large scale tree planting such as those being undertaken in other cities such as Tshwane, South Africa (Stoffberg et al., 2010), and Guangzhou, China (Jim and Chen, 2009). The results of this research suggest that such tree plantation can have greater impact in microclimatic amelioration and air pollution reduction if conducted in urbanized parts of the city with high public movement such as streets and market places, where in fact most trees have been cut rather than planted in recent years (Nagendra and Gopal, 2010).