LAND USE EFFECTS ON URBAN HEAT ISLANDS IN MARICOPA COUNTY

Abstract

Maricopa County of Arizona is the 4th most populous county in the US, growing over 20% in population between 2010 and 2020. The Urban Heat Island (UHI) phenomenon in the county has increased alongside. The continued growth of urban and suburban structures, roads, and vegetation removal have created a heating effect near the ground that can be measured by the Land Surface Temperature (LST). By comparing Landsat-8 Thermal Infrared Sensor (TIRS) data the LST and thus UHI can be analyzed to better understand the long-term costs associated with urbanization. This effect is commonly associated with the removal of vegetation and using low reflective building and paving materials which can disproportionally influence the surface temperatures and thus heat in the area. Due to the sparse desert vegetation of Maricopa County, one would suspect that the newly developed areas may not be much warmer but due to the nature of the built materials that can absorb and release more energy after the sun sets than typical Arizona dirt. However, newly planted, and harvested farmland had the largest mean LST shifts within the study period contributing to the UHI problem even though farming occurs in rural areas. The urban space needs additional considerations and model variables that county officials could consider. Using an exploratory regression with an average land use per American Community Survey census tract and a generalized linear regression, results show which areas might exacerbate UHI issues so that the associated costs can be considered as part of future planning.