The Impact of vegetation in urban microclimates

Author(s)

Paula Shinzato

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Arquitetura e Urbanismo (FAU/SBI)
• Defense date: 2009-04-24

Examining board members

Denise Helena Silva Duarte; Lucila Chebel Labaki; Paulo Renato Mesquita Pellegrino

• Advisor: Denise Helena Silva Duarte

Abstract

The main purpose of this research is the effects of vegetation in urban microclimate conditions, under the premise that the presence of vegetation influences the microclimate and its surroundings. Considering different forms of green space distribution and using native species, it could quantify the intensity and spatial distribution for the microclimate effects by a vegetated area. The modifications of air temperature and the surface temperature at the level of the pedestrians were analyzed based on energy balance and computer models. Parametric simulations on ENVI-met were done to investigate the effect of green areas distribution (linear forms, large mass of vegetation and small groups of trees) and were compared with on-site measurement data. The simulation results showed the impact of urban vegetation for climatic aspects. The outputs indicated that the vegetation effect is local and do not have a significant influence beyond the limits of the green area. Regarding to the intensity of vegetation effect, the average difference between air temperature under the trees and above the streets is 1.5ºC. While the shadowing of a dense tree (LAI=10) showed an average difference of 23ºC for superficial temperatures between green spaces and the street. This result pointed out that green area is an important strategy to mitigate the heat island effect in city centers, as it can prevent asphalt and concrete from heating and releasing long wave radiation during night time. (AU)