Assessment of Urban Heat Island and Mitigation by Urban Green Coverage

Abstract

Urban heat island (UHI) is a growing threat to human well-being and poses increasing pressure on urban utility infrastructure, especially during summer months. This study examined the UHI in Melbourne using remote sensing imagery from MODIS to derive land surface temperature (LST) for the summer of 2009. Then, the potential of urban green coverage in reducing extreme summer temperatures in Melbourne was investigated using an urban climate model for 2009 and for projected 2050 and 2090 future climates. Modeling results showed that the average summer daily maximum (ASDM) temperature differences between Melbourne CBD, suburbs and rural areas were in the range of 0.5–2.0 °C. It was also found that despite the projected climate warming in 2050 and 2090, the cooling benefit in terms of the reduction in the average summer daily maximum temperature due to various urban forms and vegetation schemes remains similar to that estimated for 2009. Thus, the cooling benefit due to various urban forms and green schemes in future climates can be reasonably projected based on the benefits identified with the present-day climate.