Monitoring Seasonal and Diurnal Surface Urban Heat Islands Variations Using Landsat-Scale Data in Hefei, China, 2000–2017

Abstract

The surface urban heat island (SUHI) is one of the most common effects of the urban ecological environment, and its long-term diurnal and seasonal fine-scale analysis remains poorly understood. This article utilized a modified reconstruction model and spatiotemporal fusion model to generate twice daily (day and night) and seasonal Landsat-scale (30 m) land surface temperature (LST) data using Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat images in Hefei, China, from 2000 to 2017. The diurnal and seasonal characteristics of SUHI variations and the complex interrelationships between SUHI and landscape patterns were analyzed. The result shows that fine-scale SUHI varied diurnally and seasonally, with a great deal of spatial heterogeneity. The fine-scale SUHI phenomenon was obvious in spring and summer during the daytime (average annual intensity of the heat island is 5.05 °C in summer, 3.26 °C in spring, 2.08 °C in autumn, and 1.90 °C in winter), and appeared at nighttime throughout the year (average annual intensity of the heat island is 2.85 °C in summer, 2.75 °C in spring, 2.69 °C in autumn, and 2.30 °C in winter). The change characteristics of landscape pattern indices in different SUHI zones reveal that construction land has an amplifying effect for SUHI, while areas dominated by vegetation and water weaken the effects of SUHI. The mitigation effect of vegetation on SUHI during the day is better than that at night.