The impact of urban ventilation corridors on land surface temperature: a temporal multisource spatial analysis of Colombo, Sri Lanka

Abstract

Urban ventilation corridors (UVCs) are essential in urban planning as they enhance air movement and help disperse heat, thereby improving air quality and contributing to a more liveable urban environment. Despite their importance, the impact of UVCs on land surface temperature (LST) within local climate zones has been under-explored. This research seeks to fill this gap by investigating the relationship between UVCs and LST, particularly in the context of temporal changes in the built environment. To achieve this, this study employed a multidisciplinary approach, combining spatial data—such as building footprint and height—meteorological information and satellite imagery. These data were used to identify UVCs, delineate local climate zones and assess LST levels in the case of Colombo, Sri Lanka. By employing cost-distance–based least-cost path calculations, the study effectively mapped potential UVCs. The findings revealed that the shift from open mid- and high-rise buildings to more compact structures significantly hinders natural airflow into urban cores. Furthermore, areas within UVCs were found to have lower temperatures compared to surrounding regions. The study also highlights the importance of maintaining compensatory spaces, such as water bodies and green spaces, and regulating building façades to enhance air circulation. Urban planners and designers should prioritize land-use management policies and strategies to improve urban liveability.