The right shade in the right place: Thermal assessment of natural and engineered shade in Tempe
The Challenge
Many cities in the Southwestern US have recognized the significance of shade for healthy urban environments and developed tree and shade master plans with city-wide canopy goals to reduce heat vulnerability. The City of Tempe’s Urban Forestry Plan envisions 25 percent tree canopy cover by 2040 with emphasis on “shading sidewalks and paths, cooling people and reducing radiated heat from hard surfaces”. The plan strongly ties into the City’s goal to become a 20-minute city, i.e. a community where residents can comfortably walk/bike to major urban hubs and amenities within 20 minutes of their homes, as outlined in the City of Tempe General Plan 2040. However, the implementation of the tree planting strategies poses several challenges to the City of Tempe. Besides water use concerns and maintenance issues, many tree planting efforts encounter urban infrastructure challenges, such as sewer lines, communication cables, or power lines that invisibly block space in right of ways from underneath. Above ground, dense tree canopy cover is a big concern for business owners when it blocks business signs. Alternative shade solutions are needed, such as awnings and shade sails, but little is known about the daytime heat mitigation efficacy and thermal comfort benefits of those shade types. To date, no actionable information is available that can help cities in Maricopa County make well-informed decisions on viable alternative shade solutions.
The Approach
This pilot study expands the “right tree in the right place” guiding principle of Tempe’s Urban Forestry Plan to “right shade in the right place” by testing the thermal comfort performance of various shade types (natural and engineered) in the context of their surroundings (underlying surface, urban form) and function of space (right of way, playground, etc.) using “MaRTy”. In collaboration with the City of Tempe, the study aims to develop guidelines and best practices that will inform the City’s active shade management strategies and can be incorporated into City ordinances and plans.
Findings and Impact
Results will be published once the project is complete.