Air temperature distribution and the influence of sky view factor in a green Singapore estate

Wong Nyuk Hien¹ and Steve Kardinal Jusuf²

Accepted for publication in Journal of Urban Planning and Development

Abstract

This paper investigates, firstly, the influence of vegetations to the air temperature distribution and secondly, the correlation between air temperature and Sky View Factor (SVF) to understand whether the trees have adverse impact especially to the nighttime air temperature since trees reduce the SVF values. Air temperature and SVF measurements were conducted in a green Singapore estate, One-North, on 1^st November 2007 – 31^st March 2008. The field measurement results show that daytime air temperature difference between dense greenery area and less greenery area is 2.4K and the nighttime air temperature difference is 1.1K. The temperature maps study provides a clear picture on the air temperature distribution across the One-North estate and concludes that parks or clusters of trees are able to maintain both daytime and nighttime air temperature at a cool level. Statistical analysis was conducted to analyze the correlation between air temperature and SVF. During daytime, there is a significant and good correlation between air temperature and SVF. The higher the SVF, the higher is the air temperature. Trees reduce the sky openness and provide shading to the environment. At nighttime, there is a weak correlation between air temperature and SVF. Thus, there is no adverse impact, i.e. reduction of nighttime net long-wave loss, due to the reduction of SVF by trees.

Keywords: air temperature distribution, Sky View Factor (SVF), correlation analysis, green Singapore estate, tropical climate.