Balancing Density and Greenery: Addressing Urban Heat Islands in Transit-Oriented Development

This study explores the relationship between urban form, green infrastructure, and the Urban Heat Island (UHI) effect in Manchester's Transit-Oriented Development (TOD) neighbourhoods: Manchester Piccadilly and East Didsbury. The research investigates how urban density, characterised by deep street canyons and lack of green spaces, influences the intensity of UHI effects. Land Surface Temperature (LST) and Normalised Difference Vegetation Index (NDVI) were mapped using remote sensing techniques to identify spatial patterns of heat intensity and vegetation coverage, respectively. The analysis revealed significant negative correlations between NDVI and UHI intensity in both areas, with East Didsbury exhibiting a stronger correlation than Manchester Piccadilly. This result suggests that higher vegetation density contributes to cooling and mitigates UHI effects more effectively in areas with more expansive green areas. Furthermore, regression analysis of street canyon and UHI intensity demonstrated a positive relationship in both neighbourhoods, with Manchester Piccadilly showing a stronger association due to its higher building density and limited green areas. The results highlight the critical role of urban geometry and green cover in moderating UHI effects, particularly in dense urban TODs where the urban canyon effect is more pronounced. The study emphasises the importance of integrating green infrastructure in TOD areas, particularly in high-density environments where altering urban form is challenging. Recommendations include prioritising the expansion of green infrastructure, such as green roofs and tree canopy coverage, as offsetting techniques to mitigate the adverse impacts of UHI.