An Investigation into Minimizing Urban Heat Island (UHI) Effects: A UK Perspective

Cities are major sources of Green House Gas (GHG) emissions and the effects of mass urbanization upon the environment have now become clear. Great opportunities exist within cities for tackling climate change. Urban Heat Island (UHI) effect is a phenomenon where significant temperature difference between inner micro-climates of a city and their neighboring micro-climates can be perceived. Mitigation of UHI effects can positively contribute to alleviate detriments of climate change. This research project aims to investigate effective and resilient UHI mitigation strategies and to provide guidance for their application in future. A review of literature indicates that UHI is a growing problem in the UK and that mitigation of such effects would enhance sustainable development at urban scale. The lack of guidance for designers and planners looking into mitigating the UHI effect is also identified. Utilizing ENVI-met simulations and through Urban Futures Assessment Method (UFAM), this research identifies and tests resilient and effective UHI mitigation strategies. Results show that building form, orientation and layout are among the most effective UHI mitigation strategies. Trees, shrubs and grass (TSG), and use of high albedo materials (HAM) in external building surfaces are also indicated as effective measures whose success is dependent on building form. All assessed mitigation strategies (TSG, HAM, UIWB) are shown to have a similar level of resilience which could be improved if properly future-proofed against subsequent changes. Accordingly some practical suggestions are provided to help improve the resilience of tested UHI mitigation strategies.