Evaluating the Environmental Justice of Tree Canopy Connectivity in Pheonix, Arizona, USA

Abstract

Phoenix, Arizona, a metropolis located in the Sonoran Desert in southwester USA, is expected to see major disturbances resulting from global warming, including excessive heat events1 and drought2. Urban Green Infrastructure (UGI) has the potential to help mitigate excessive heat3 yet, as water becomes increasingly scarce, efficiency in both the location and configuration of UGI is critical to maximize its positive benefits.  Well-connected UGI provides more ecosystem services and can better mitigate extreme temperatures in urban areas than poorly connected UGI 4. However, owing in part to the current and anticipated scarcity of water, the distribution and connectivity of this lifesaving resource has the potential to be unjust regarding economically vulnerable communities. The purpose of this study is to determine if there are relationships between the coverage/connectivity of Phoenix UGI and sociodemographic variables associated with vulnerability.  Using a 2010 1m landcover classification raster and the landscapemetrics R package, landscape metrics were calculated for sample plots withing areas zoned for single-family residential homes.  Vulnerability statistics were then apportioned for each plot using 2010 ASTER/CDC Social Vulnerability Index data. These variables were then examined to determine relationships between connectivity and vulnerability using Principal Component Analysis.      1.  Stone, B. et al. Climate change and infrastructure risk: Indoor heat exposure during a concurrent heat wave and blackout event in Phoenix, Arizona.Urban Climate 36, 100787 (2021). 2.  Bolin, B., Seetharam, M. & Pompeii, B. Water resources, climate change, and urban vulnerability: a case study of Phoenix, Arizona. Local Environment 15, 261–279 (2010). 3.  Marando, F. et al. Urban heat island mitigation by green infrastructure in European Functional Urban Areas. Sustainable Cities and Society 77, 103564 (2022). 4.  Debbage, N. & Shepherd, J. M. The urban heat island effect and city contiguity. Computers, Environment and Urban Systems 54, 181–194 (2015).