Online Decision-Making Tool for Active Shade Management

Shade is an important design feature to mitigate heat stress, especially in hot, dry cities. The impact of shade on people is localized, site-specific, and context-dependent. It varies diurnally and seasonally by shade infrastructure, orientation, and ground cover. As cities seek to address shade deserts, i.e. urban areas lacking the shade needed to reduce heat burden and protect human health, tools are needed to choose the right shade for the right place. We developed a web-based decision support tool that generates shade performance curves for various shade types to explore the cooling performance of shade infrastructure in the built environment. The user can choose parameters such as shade type, size, location, and date to evaluate which shade infrastructure performs the best in terms of heat load reduction on the human body. The website displays a rendered hemispherical view of the shade infrastructure based on the chosen parameters. A graph displays the evolution of the hourly daytime mean radiant temperature (heat load) reduction ΔMRT that a person experiences when standing under the shade compared to a sun-exposed location. The tool was validated for hot, sunny summer days in the Phoenix metropolitan area using the human-biometeorological cart MaRTy. A sensitivity analysis showed the shade performance across three shade types (tree, umbrellas, bus shelter), different seasons, and times of day. The web-based decision-making tool will allow users to assess the heat load impacts of customized, site-specific shade interventions for active shade management and help planners and designers in choosing the right shade for the right place.