Urban canals can reduce temperatures in their immediate surroundings by more than 2°C during heat waves [1].
This finding suggests that existing city waterways can serve as critical infrastructure for mitigating the urban heat island effect during extreme weather. As cities face more frequent heat events, understanding the cooling capacity of blue spaces helps urban planners design more resilient environments.
Researchers from the University of Manchester conducted the study, focusing on urban areas across Great Britain and Ireland [2]. The team found that the cooling effect of these canals is not limited to the water's edge but extends up to 50 meters from the banks [2].
The cooling occurs because water bodies provide evaporative cooling and moderate the ambient temperatures of the air around them [1]. This process helps lower the heat trapped by concrete and asphalt, materials that typically absorb and radiate heat in dense city centers.
While the research highlights the benefits of canals, the extent of the cooling depends on the scale of the water body and the surrounding urban layout. The study specifically notes the effectiveness of these waterways during peak heat events [1].
By identifying the specific range of this cooling effect, the research provides a measurable metric for city officials. This data allows for better planning of green and blue corridors to protect vulnerable populations from heat-related illness during summer peaks [2].
“Urban canals can reduce temperatures in their immediate surroundings by more than 2°C during heat waves”
This research quantifies the 'cooling island' effect of urban waterways, providing a blueprint for nature-based solutions in urban planning. By proving that cooling extends 50 meters from the bank, the study suggests that zoning for residential or public spaces near canals can significantly reduce the need for energy-intensive air conditioning and lower heat-related health risks during extreme weather events.
