TITLE:
Urban Heat Island Effects during Heatwave Periods in Dalian from the Perspective of Local Climate Zones
AUTHORS:
Linze Li, Gaoyu Li
KEYWORDS:
Local Climate Zone (LCZ), Surface Urban Heat Island Intensity (SUHII), Heatwave, Cold-Region City, GeoDetector
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.16 No.6,
June
5,
2026
ABSTRACT: Under the background of global climate warming and accelerated urbanization, the frequency and intensity of extreme heat events have continued to increase, leading to increasingly prominent urban thermal environmental issues in traditionally cold-region cities. During the summer of 2018, Northeast China experienced one of the most severe regional heatwave events in recent years. As a representative coastal cold-region city in China, Dalian exhibited a markedly intensified urban heat island effect under the influence of this extreme climatic event. This study focused on the main urban area of Dalian and used the Local Climate Zone (LCZ) classification framework in conjunction with remote sensing land surface temperature (LST) data to quantitatively analyze the spatial distribution characteristics of surface urban heat island intensity (SUHII) during the representative heatwave summer of 2018. Furthermore, multiple urban environmental factors were incorporated, and the GeoDetector model was used to systematically investigate the driving mechanisms underlying the urban heat island effect. The results indicate that: 1) the spatial distribution of LCZs in the main urban area of Dalian exhibited a distinct pattern characterized by “coastal agglomeration and inland transition”, with different underlying surface types providing the fundamental basis for thermal environmental differentiation; 2) under heatwave conditions, the land surface thermal environment demonstrated significant spatial heterogeneity, with high-temperature areas primarily concentrated in the urban core and coastal industrial zones, whereas low-temperature areas were mainly regulated by water bodies and mountainous vegetation. Overall, the spatial pattern was characterized by “enhanced warming in built-up areas and localized cooling in ecological spaces”, and the spatial distribution of SUHII corresponds well with LCZ types; 3) GeoDetector analysis revealed that surface imperviousness was the dominant driving factor, while water bodies and vegetation exert important regulatory effects. Population density also significantly influenced the spatial differentiation of the urban heat island effect, whereas topographic effects were comparatively limited; interactions among multiple factors all exhibited enhancement effects, among which the coupling of surface imperviousness with water bodies, vegetation, and human activities provided the strongest explanatory power for the spatial pattern of the urban heat island, indicating that the heat island effect was jointly driven by multiple factors and was substantially intensified through their combined interactions. The findings of this study can provide a scientific basis for thermal environment regulation and climate-adaptive urban planning in cold-region cities.