During summer 2015, a study was conducted to characterize effects of tree species and shade structures on outdoor human thermal comfort under hot, arid conditions. Motivating the research was the hypothesis that tree species and shade structures will vary in their capacity to improve thermal comfort due to their respective abilities to attenuate solar radiation. Micrometeorological data was collected in full sun and under shade of six landscape tree species and park ramadas in Phoenix, AZ during pre-monsoon summer afternoons. The six landscape tree species included: Arizona ash (Fraxinus velutina Torr.), Mexican palo verde (Parkinsonia aculeata L.), Aleppo pine (Pinus halepensis Mill.), South American mesquite (Prosopis spp. L.), Texas live oak (Quercus virginiana for. fusiformis Mill.), and Chinese elm (Ulmus parvifolia Jacq.). Results showed that the tree species and ramadas were not similarly effective at improving thermal comfort, represented by physiologically equivalent temperature (PET). The difference between PET in full sun and under shade was greater under Fraxinus and Quercus than under Parkinsonia, Prosopis, and ramadas by 2.9-4.3 °C. Radiation was a significant driver of PET (p<0.0001, R2=0.69) and with the exception of ramadas, lower radiation corresponded with lower PET. Variations observed in this study suggest selecting trees or structures that attenuate the most solar radiation is a potential strategy for optimizing PET.
The intent of this study is to develop a new eco-cultural design model of development for the Salt River watershed and surrounding areas with renewed respect for the land in modern society. It includes both conceptual and practical community guides to facilitate and catalyze a new community-driven typology of planning prepared for rapid community change and climate challenges. This study includes the review of prominent existing projects, both regionally and globally, with expertise in the areas of urban development, culture and place keeping/making, ecology and water management. This study aims to exhibit the diverse components of urbanism and its effects on the Salt River corridor, surrounding urban ecosystems and climate. This thesis argues for simultaneous and codependent cultural and ecological growth and healing, and its necessity for sustainable urban development. Lastly, an urban revitalization framework is manifested in a community-oriented handbook based on key findings to produce a unified vision executed by watershed community co-design of the Phoenix metropolitan area.