Improved urban heat island mitigation using bioclimatic redevelopment along an urban waterfront at Victoria Dockside, Hong Kong

Abstract

Bioclimatic design provides solutions to mitigating the urban heat island (UHI) effect and improving urban quality of life. Waterfront settings provide a unique opportunity for UHI mitigation, as cool winds (i.e. sea breezes) provide good cooling conditions. We used ENVI-met numerical simulations to investigate the synergistic mitigation effects of redeveloped urban forms, ventilation corridors, and extensive greenery on local microclimate and outdoor thermal comfort at an urban waterfront in Victoria Harbour, Hong Kong. The thermal performance along the waterfront and within an inner urbanised area was evaluated in three scenarios: existing configuration (Case A), redeveloped building form (Case B), and Case B with a ventilation corridor and extensive greenery added. In the study area's subtropical climate, the additional strategies used led to a synergistic improvement in microclimate and thermal comfort in both settings. The appropriate use of combined urban forms and ventilation corridors along waterfronts can thus lead to a more acceptable pedestrian-level wind environment and enhance the ventilation potential within inner urbanised areas. The cooling intensity of greenery (turf and green facades) along such waterfronts can also be extended for further benefits. Overall, the synergistic mitigation effects of redeveloped urban forms, ventilation corridors, and extensive greenery in proximity to water bodies demonstrated here provide science-based guidance for the use of bioclimatic design along urban waterfronts in order to achieve improved microclimates and thermal comfort at neighbourhood scales.