Insights Wales – Outdoor human thermal comfort and urban heat island in local climate zones in Cardiff

Dr. Tania Sharmin

Outdoor thermal comfort (OTC) is an important factor in determining the health and wellbeing of people using urban spaces. Favourable OTC conditions, such as shaded areas, cool or permeable pavements and access to green spaces can help to mitigate the negative effects of extreme heat and cold and improve the quality of life in urban areas.

However, many urban spaces in cities are designed with rather ambiguous climate-design approaches without considering the necessary evidence-base or performance analysis. This means that climatic and comfort aspects are not considered in the design process, which can lead to unutilised spaces or spaces that have negative effects on public health and wellbeing. Hence it is crucial to evaluate the environmental performance of exiting urban spaces in cities to provide insights for climate-sensitive urban design. This is particularly essential for protecting the cities and their valuable social and urban life from rapid urban warming, urban heat island (UHI) effects and frequent heat waves in relation to climate change. During heatwaves, the UHI effect can further increase air temperatures in urban areas, leading to increased heat stress, air pollution, and energy consumption. Despite being the capital of Wales there has been limited research to examine the OTC and UHI conditions in Cardiff.

In this study, we have examined the OTC and UHI for the local climate zones (LCZs) for Cardiff. The study adopts a GIS-based approach to generate a LCZ map for urban climate classification of Cardiff and apply land surface temperature (LST) maps to identify the hot spots in Cardiff using Landsat 8 satellite data. Then it focuses on several public urban spaces in Cardiff to determine the mean radiant temperature (Tmrt), an important parameter that controls human energy balance and thermal comfort of people. A comparison of Tmrt in the urban spaces will aid in understanding the spatial variation, their OTC conditions. The findings of this study will help to identify vulnerable areas in terms of UHI and OTC and take mitigating measures, accordingly, thus helping to improve the resilience of the city in a changing climate.

About the Speaker

Tania is an architect and researcher with a background in environmental design, energy performance of buildings (thermal modelling), CFD microclimate modelling, outdoor thermal comfort and climate-responsive urban design. Tania is a Fung Global Fellow 2022-23 of Princeton Institute for International and Regional Studies (PIIRS) and a Senior Lecturer (Associate Professor)  in Sustainable Environmental Design in Architecture at the Welsh School of Architecture, Cardiff University. Previously, she worked as a postdoctoral research associate at the University of Cambridge for Managing Air for Green Inner Cities (MAGIC), developing urban scenarios to investigate the influence of the built environment on air pollution and UHI impact.

Find out more

Comments are closed.