Spatio-Temporal Modeling of the Urban Heat Island in the Phoenix Metropolitan Area: Land Use Change Implications

TLDR

Vegetation cover reduces land surface temperature by increasing latent heat flux and decreasing sensible heat flux, thereby cooling urban environments. The study aims to map spatial and temporal variations of the surface urban heat island in Phoenix and determine how land‑use/land‑cover changes from 2000 to 2014 drive these variations. Using MODIS 8‑day composite LST imagery and Landsat‑derived LULC maps for 2000 and 2014, the authors analyze SUHI intensity across the metropolitan area. The analysis reveals that the greatest LST increases occurred on Phoenix’s outskirts, driven mainly by conversion to urban, residential, and impervious surfaces, indicating that expanding vegetation could mitigate the heat island effect.

Abstract

This study examines the spatial and temporal patterns of the surface urban heat island (SUHI) intensity in the Phoenix metropolitan area and the relationship with land use land cover (LULC) change between 2000 and 2014. The objective is to identify specific regions in Phoenix that have been increasingly heated and cooled to further understand how LULC change influences the SUHI intensity. The data employed include MODerate-resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) 8-day composite June imagery, and classified LULC maps generated using 2000 and 2014 Landsat imagery. Results show that the regions that experienced the most significant LST changes during the study period are primarily on the outskirts of the Phoenix metropolitan area for both daytime and nighttime. The conversion to urban, residential, and impervious surfaces from all other LULC types has been identified as the primary cause of the UHI effect in Phoenix. Vegetation cover has been shown to significantly lower LST for both daytime and nighttime due to its strong cooling effect by producing more latent heat flux and less sensible heat flux. We suggest that urban planners, decision-makers, and city managers formulate new policies and regulations that encourage residential, commercial, and industrial developers to include more vegetation when planning new construction.