The relationship between roof greening and thermal environment in Taipei city.

Abstract

The relationship between green roofs and the thermal environment in Taipei city C.-Y. Sun Department of Land Economics, National Chengchi University, Taiwan Abstract During the last decade, a large amount of research has been published in Taiwan on different strategies for the reduction of the urban heat island effect. The most important strategy for reducing ambient temperature and mitigating the heat island effect is encouraging citizens to build a green roof on their own buildings. In order to analyze the effect of green roofs on the thermal environment, this paper collects temperature and humidity data from two buildings with different roof greening levels and tries to analyze the relationship between roof greening and the thermal environment in Taipei city. The result of this research can give citizens an idea what kind of thermal environment they can get if they make some greening on their roofs; moreover, it also can provide some useful data to governments for calculating the environmental benefit if they carry out the green roof policy. Keywords: heat island effect, green roof, greening level. 1 Introduction Taipei is the biggest metropolis of Taiwan, which has around 5,000,000 citizens with a very high living density. The high concentration of buildings in the city has resulted in many environmental issues, such as air pollution, traffic jams, urban warming and the urban heat island effect. In order to solve these problems, several studies indicated that green roofs can be used to mitigate some problems associated with storm water runoff, the urban heat island effect, wildlife habitat, air quality and energy consumption (Liu and Baskaran [1]; Wong et al. [2]; Takebayashi and Moriyama [4]). In recent years, due to ecological concerns, the government has promoted the building of sustainable architecture to mitigate the building’s negative impact on the urban environment and to create harmony