Economic and environmental benefits of cool pavements: a case study of Bhubaneswar city.

Abstract

The change of land use from natural lands to built-up areas is one of the key reasons for the urban heat island (UHI) effect, because of absorbance and storing of heat energy. Roads and streets cover a significant fraction of the urban fabric and are continuously exposed to solar radiation. This study examines the impact of pavement surface temperature on urban air temperature. Measurements were made across the Bhubaneswar city to capture the temperature and relative humidity along the major arterial roads. The study quantified the UHI effect and evaluated the benefits of cool pavements in reducing air temperature and improving energy efficiency. The study reveals a strong relation between pavement surface temperature and near-surface air temperature. It was found that up to 1.5 m above the pavement surface, the impact of pavement surface temperature on the air temperature is substantial. On a particularly hot summer day, the air temperature just above the pavement surface and at 1.5 m above the surface was observed to be higher than the surrounding ambient air temperature by up to 7.4 °C and 2 °C, respectively. Based on the measurements taken during this limited period, the peak UHI intensity in Bhubaneswar city was found to be ~ 1.9 °C, which is high, if the current developments of the city are taken into consideration. This study also indicates that significant economic and environmental benefits can be achieved with the adoption of cool pavement technologies.