Climatic-responsive planning and action for mitigating heat-related health risk at community level in high density cities– A Case of Hong Kong  (14611517) (1 Jul 17 - 31 Dec 20)
• Researchers: REN Chao, William GOGGINS, Kevin LAU
• Funding Amount: HK$551,992
• Funding source: Research Grants Council - General Research Fund

More frequent and intense extreme hot weather will be experienced under future climate change (IPCC, 2012). Because of the urban heat island effect, the problem in high density cities will be exacerbated in summer (WMO & WHO, 2015). The quality of urban thermal environment will deteriorate, and thus, heat-related health risk, especially to the poor and the elder people will increase. A spatial understanding of heat-related health risk at the community level is needed for more climate-responsive design and decision-making.

Previous studies adopted “Crichton’s Risk Triangle (RT)” hazard-risk assessment methodology to explore and quantify the relationship between extreme hot weather, heat exposure, vulnerability and risk. It was also suggested that they were associated with the social, economic and environmental aspects of urban living conditions. However, most of them were conducted in low- to medium-density cities in temperate climates (Lindley et al., 2006;Morabito et al.,2015; Tomlinson et al., 2011). There is a lack of studies conducted in high-density urban environment. In addition, environmental evaluations on urban morphological characteristics are generally limited.

Hong Kong is a high-density city in terms of both the built environment and population. Its hot humid subtropical climate combined with future climate change will increase the duration, frequency and intensity of extreme hot weather events (HKO, 2015). In addition, due to its high-density inhomogeneous urban morphology, intra-urban temperature differences are highly variable. It is therefore important to acquire spatial and quantitative understandings of heat exposure and vulnerability under extreme hot weather.

The proposed project aims to contribute by: (i) collecting and collating social, economic and environmental information of each of the Territory Planning Unit in geographic information system (GIS); (ii) investigating the variation of intra-urban temperature under extreme hot weather conditions (daytime and nighttime) to quantify the magnitude of extreme hot weathers; (iii) adopting the RT statistical method to map out heat exposure and vulnerability at community level; (iv) based on the above findings, developing a heat-related risk map with five risk levels; and (v) drawing up a climate-responsive design action list and providing a reference to planners and governors when they are considering land use, landscape planning and development intensity.

The project will provide a methodology for a more comprehensive understanding of heat risk in subtropical high density cities. It will address the call for better management of heat risk and response from the WMO and WHO. The Urban Climatic Planning Recommendation Map, developed by the Planning Department of Hong Kong Government, will be enhanced by the spatial understanding of heat risk obtained by the proposed study and it will enable a more comprehensive analysis of public health impact under extreme hot weather.