A multi-disciplinary study of urban climatology and urban planning for densely populated cities

Abstract

While there are researches concerning environmental properties of buildings such as IAQ, there are limited researches that adopt multidisciplinary approach to urban sustainability, especially with respect to urban climatology through which Urban Heat Island is a topical study of environmental impacts from microclimate on planning in densely populated areas. The threats of diseases such as SARS in densely populated cities suggests that it is mandatory to integrate urban climatologically indicators into urban design of our cities. Such integration will not only help to improve living condition and healthy environment; it can also serve as a means to quantify energy savings and environmental benefits for purpose of planning policies of land resources. In Hong Kong, nearly 60% of electrical energy use is for space conditioning during summer months. This paper describes findings of an ongoing research project at the University of Hong Kong that investigates the impact of design-related variables on outdoor micro level daytime heat island effect in residential developments that have in turn an impact on the mode and pattern of air conditioning energy consumption. The study hypothesizes that differences in outdoor temperatures within and between residential developments can be explained by the impact of design related variables on the overall environment. Any studies on environmental issues should be stratified to incorporate geographical and seasonal variation. The study covers several high-rise high-density residential areas, including mixed development urban blocks in inner city as well as coastal developments. The findings of the study will lead to specific environmental design guidelines in terms of density, building height, massing, and vegetation. These guidelines would help practitioners to make design decisions at micro-urban and urban scales. The overall impact of any physical development in urban residential areas of Hong Kong and other similar Asian cities can also be analyzed accordingly. These guidelines will help designers to quantify crucial factors for low energy urban design at the concept design stage itself and mitigate UHI in the long term for subtropical climate cities.