Influence of selection of rural reference area for quantifying the surface urban heat islands intensity in major South Korean cities

Abstract

Surface urban heat island intensity (SUHII), which is the difference in land surface temperature (LST) between urban and rural areas, depends on selection of rural reference and studies that have analyzed the impacts of different methods on estimating SUHII are few. This study aims to analyze impact of two different methods for defining rural areas, buffer area around city, and non-urban areas within city, on estimating SUHII in five major cities of South Korea using satellite measurements for period 2018–2022. Using a buffer region around city to define rural reference area results in a higher estimate of SUHII compared to using rural areas within city limits. The largest differences in SUHII were found in Seoul (both day and night) and Busan (night), with Seoul exhibiting a difference of 1.14°C (day) and 1.51°C (night), and the differences are mostly driven by the physical characteristics of the city and geographical location.