THE INFLUENCE OF HOUSING DENSITY AND URBAN DESIGN ON THE SURFACE ENERGY BALANCE AND LOCAL CLIMATES OF MELBOURNE AUSTRALIA, AND THE IMPACT OF MELBOURNE 2030’s VISION

By the year 2003, 47% of the world’s 6.3 billion inhabitants were living in urban areas, while in more developed countries, 75% of the population (1.2 billion) lived in urban areas (Population Reference Bureau, 2003). As more and more people make their residencies in the heart of the industrial and commercial world, urbanisation will continue to grow. Alterations to the natural environment due to the physical structure of the city, and its artificial energy and pollution emissions, interact to form distinct urban climates (Bridgeman et al., 1995). These urban climates can often be undesirable causing increases in air pollution and aiding the formation of Urban Heat Islands (UHI). Urban warming can have substantial implications on air quality and human health (Stone and Rodgers, 2001). For instance, the UHI effect can exacerbate hot weather conditions and lead to increases in mortality both directly and indirectly, as seen from the European heat wave event in 2003, which is said to have been compounded by the urban environment, and related to 20,000 deaths (Schar et al., 2004). Those with increased vulnerability include the elderly, low income earners, and residents in high density, older housing stock with limited surrounding vegetation (Smoyer-Tomic et al., 2003). The UHI effect can be mitigated via environmental modification, particularly through controlled and structured urban design measures that can reduce heat stress related illnesses. Unfortunately, despite the obvious existence of UHI’s in most cities, few cities have developed comprehensive programs for its mitigation (Stone and Rodgers, 2001).