THE URBAN HEAT ISLAND EFFECT AND ITS IMPACT ON THE CLIMATE AND LANDSCAPE OF PHOENIX, ARIZONA

This paper examines the impact of the urban heat island effect on the climate and landscape of Phoenix, Arizona. Urbanization is quickly becoming the most influential environmental factor because of the exponential growth in the human population coupled with industrialization, modernization, and commercialization, which has become the allure of urban centers worldwide. While urbanization offers numerous advantages, it comes at the cost of altering the environment by replacing permeable natural soils and vegetation with impermeable urban surfaces, such as pavements, buildings, and other such structures. This impervious modification results in absorption of solar energy that is taken up by the surfaces, resulting in an “island” of higher temperatures that distinguish the urban centers from the surrounding, cooler rural areas, aptly named the urban heat island effect. In Phoenix, there has been an increase in the annual mean average temperatures while rural Sedona (Arizona) has seen stable temperatures. Additionally, the Phoenix area has low annual precipitation rates accompanied by high evaporation rates. Apart from a few localities within the Phoenix area, there is a general trend of decreasing groundwater levels. Increasing temperatures and decreasing groundwater levels have a few consequences, including increased danger of land subsidence, increased demand and consumption of energy, and intensifying the effects of the existing desert climate. To mitigate the consequences of the urban heat island, Phoenix’s urban policies must be modified to: (1) increase green infrastructures and recreational areas, (2) increase albedo on urban surfaces, (3) increase multi-storied buildings equipped with green roofs, and (4) reduce dependence on private transportation.