Greenspace, bluespace, and their interactive influence on urban thermal environments

Urbanization has continued growing dramatically in the past few decades, as more than half of the global population live in urban areas. The alternation of surface materials and morphologic characteristics in urban areas and anthropogenic emissions from daily activities have been evident with a considerable influence on a wide spectrum of local climate, hydrologic cycles, and ecologic patterns. Decades of research efforts have enlightened our physical understanding of the impacts of LULC on urban climates. In addition, such knowledge has provided a scientific basis for adaptation and mitigation strategies in cities to counteract the risks associated with adverse climate effects. Examples include the adoption of high albedo roofs and pavements to alleviate heat stress and harnessing the evapotranspirative cooling power of urban greenspace and blue space (water bodies, including lakes, rivers, etc.) to provide a more comfortable thermal environment. Building on multiple-year dense observations from the ground networks and high-resolution spaceborne thermal measurements, this presentation will discuss the heat mitigation capacity of nature-based cooling infrastructures, such as green space and blue space.   Specifically, we will compare the thermal benefits of different cooling infrastructures, and how their spatial organization, and coverage yield different diurnal effects at both the microclimate scale and the city scale. The study shed light on their individual and interactive effects under different meteorological conditions, which offers new insights into the cooling benefit of excising urban amenities under various synoptical conditions, including extreme heat events. The findings provide critical information support to invest in future natural-based cooling amenities in cities as the heat threats grow dramatically on a global scale.