Featured Research

from universities, journals, and other organizations

Too Many Trees Planted In Central Strip Of Roads Can Be Worse Than None; Can Trap Vehicle Exhaust Fumes

Date:
July 21, 2009
Source:
Inderscience
Summary:
A new study suggests that we can improve city environments by planting trees down the middle of streets provided they are not too close together. Too many trees planted close together along a central strip, as is common in many major European cities could lead to more vehicle exhaust fumes being trapped in the urban canyon than would occur if there were no trees.

A new study published in the International Journal of Environment and Waste Management suggests that we can improve city environments by planting trees down the middle of streets provided they are not too close together.

Christof Gromke now of the WSL Institute for Snow and Avalanche Research SLF in Davos, Switzerland, and Bodo Ruck of the Institute for Hydromechanics at the University of Karlsruhe, Germany, have investigated the effects of trees on ventilation and pollution levels along city streets lined with densely packed tall buildings, so called urban canyons.

The team's wind tunnel study investigated how air flows along canyon-like city streets and how this is affected by the street having a central line of trees. They looked at how air flows along and upward from the urban canyons and the effect of different spacing for trees and how stationary or moving traffic affects air flow.

Their results suggest that streets with too many trees planted close together along a central strip, as is common in many major European cities could lead to more vehicle exhaust fumes being trapped in the urban canyon than would occur if there were no trees. Specifically, the leafy canopies of a high density tree line hinder the upward flow of pollutants. They also damp down the swirling eddies of air that would otherwise help exhaust gases escape the street.

The study does not advocate removing trees from city streets, of course. Further investigation revealed that a wider spacing of trees, with trees separated by at least the width of their crowns enables pollution-carrying eddies to form and allows the air at street level to clear much more quickly especially when traffic is not at a standstill.

The research could help town planners improve city environments by choosing the optimum spacing of trees when planting new streets or to pollard more appropriately to improve airflow in streets with established tree lines.


Story Source:

The above story is based on materials provided by Inderscience. Note: Materials may be edited for content and length.


Journal Reference:

  1. Effects of trees on the dilution of vehicle exhaust emissions in urban street canyons. Int. J. Environment and Waste Management, 2009, 4, 225-242

Cite This Page:

Inderscience. "Too Many Trees Planted In Central Strip Of Roads Can Be Worse Than None; Can Trap Vehicle Exhaust Fumes." ScienceDaily. ScienceDaily, 21 July 2009. <www.sciencedaily.com/releases/2009/07/090720105127.htm>.
Inderscience. (2009, July 21). Too Many Trees Planted In Central Strip Of Roads Can Be Worse Than None; Can Trap Vehicle Exhaust Fumes. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2009/07/090720105127.htm
Inderscience. "Too Many Trees Planted In Central Strip Of Roads Can Be Worse Than None; Can Trap Vehicle Exhaust Fumes." ScienceDaily. www.sciencedaily.com/releases/2009/07/090720105127.htm (accessed August 22, 2014).

Share This




More Plants & Animals News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) — An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) — According to a new study, spiders that live in cities are bigger, fatter and multiply faster. Video provided by Newsy
Powered by NewsLook.com
Lost Brain Cells To Blame For Sleep Problems Among Seniors

Lost Brain Cells To Blame For Sleep Problems Among Seniors

Newsy (Aug. 21, 2014) — According to a new study, elderly people might have trouble sleeping because of the loss of a certain group of neurons in the brain. Video provided by Newsy
Powered by NewsLook.com
Ramen Health Risks: The Dark Side of the Noodle

Ramen Health Risks: The Dark Side of the Noodle

AP (Aug. 21, 2014) — South Koreans eat more instant ramen noodles per capita than anywhere else in the world. But American researchers say eating too much may increase the risk of diabetes, heart disease and stroke. (Aug. 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins