Plan Evaluation for Heat Resilience: City of Mesa, AZ

Abstract

The combination of climate change and the urban heat island (UHI) effect is increasing the number of dangerously hot days and the need for all communities to plan for urban heat resilience equitably. Urban heat resilience requires an integrated planning approach that coordinates strategies across community plans and uses the best available heat risk information to prioritize heat mitigation and management strategies for the most vulnerable communities. This report, supported by the U.S. DOE-funded Southwest Urban Corridor Integrated Field Laboratory (SW-IFL), summarizes the findings from two complementary methods for examining how different city plans shape urban heat resilience.

The first methodology, Plan Quality Evaluation for Heat Resilience, provides a broad assessment of how plans address heat and their effectiveness likelihood. We adapted well-established plan quality assessment approaches to heat (Meerow et al. 2024). We then applied the methodology to assess whether Mesa’s plans meet 56 criteria across seven established principles of high-quality heat resilience planning. We also cataloged the types of heat mitigation and management strategies included in the plans.

The second methodology, the Plan Integration for Resilience Scorecard™ (PIRS™) for Heat provides a more detailed assessment of the heat mitigation policies and their spatial alignment with heat vulnerability. PIRS™ for Heat was developed as an extension of the original Plan Integration for Resilience Scorecard™, a methodology developed by Berke et al. (2015) and then further advanced and translated to planning practice by Malecha et al. (2019), for spatially evaluating networks of plans to reduce vulnerability to hazards. With support from the U.S. National Oceanic and Atmospheric Administration (NOAA) Climate Program Office’s Extreme Heat Risk Initiative and in partnership with the American Planning Association, PIRS™ for Heat was initially piloted in five geographically diverse U.S. communities, including Baltimore, MD, Boston, MA, Fort Lauderdale, FL, Seattle, WA, and Houston, TX. The rationale, methodology, and findings from the first five cities are published in the guidebook The Plan Integration for Resilience Scorecard™ (PIRS™) for Heat: Spatially evaluating networks of plans to mitigate heat.

We analyzed all policies in Mesa’s network of plans, including their comprehensive plan, hazard mitigation plan, and climate action plan. Policies were only included if they had the potential to impact urban heat, were place-specific, and contained a recognizable policy tool. Policies were then scored based on how they would likely impact urban heat. Scored policies were mapped to relevant census tracts across the city to evaluate their spatial distribution and the net effect on urban heat. The resulting PIRS™ for Heat scorecard was then compared with physical and social vulnerability data to assess policy alignment with heat risks and to identify opportunities for improved urban heat resilience planning.