Biophysical factors of remote sensing approach in urban green analysis

Abstract

Greenery in an urban environment is an important consideration when studying temperature, and such enquiry can benefit human health. The purpose of this paper is to investigate how ambient temperature in urban areas is affected by forests and parks. The focus is on biophysical parameters related to these green areas, such as impervious surface percentages, albedo, areal coverage, elevation, and leaf area index (LAI). Geographic information systems and remote sensing were used to quantify green spaces using a pixel-based method. It was found that coverage area has little correlation with temperature. Factor analysis was used to determine the minimum number of independent factors, which explained 63% of the variance of that temperature. Only elevation, LAI and albedo were significant biophysical factors. Guidelines for greenery programmes should include these significant data-sets to understand the influence of green areas on heat reduction.

Keywords:

• estimated ambient temperature
• green areas
• geographic information systems
• remote sensing

Acknowledgements

The authors are deeply grateful to the United States Geological Survey (USGS) for providing the satellite images. Many thanks go to the Institute of Research Management & Monitoring (IPPP), grant no: PV079/2011B from the University of Malaya (UM), International Islamic University of Malaysia (IIUM), and Ministry of Education (MOE) for their support under the research grants and scholarships.