Analyzing the Impacts of High-Albedo Surfaces on Outdoor Thermal Environments in Antwerp Within the Local Climate Zone Framework

Abstract: With the rapid pace of urbanization, the urban heat island (UHI) effect has become a significant challenge faced by most cities globally, especially in warmer climate regions. In response to this issue, the use of high-albedo surface materials has gained attention as an effective urban climate adaptation strategy. High-albedo surfaces reflect more solar radiation, reducing heat absorption by the urban environment, and thereby helping to lower local temperatures. This study evaluated the potential effects of applying high-albedo surfaces on the outdoor thermal environments in various local climate zones (LCZs) within Antwerp by utilizing high-resolution meteorological data, satellite imagery, and Urban Weather Generator (UWG). The analysis is divided into two parts. First, Urban climate modeling identified notable day-night fluctuations in UHI intensity across LCZs. In August, LCZ2 (open mid-rise) recorded the highest daytime heat buildup, peaking at 1.5°C above rural temperatures by midday, with a subsequent delay in nighttime cooling. Conversely, December exhibited more consistent UHI patterns across all zones, with reduced temperature variability. This highlights the critical role of solar exposure and heat retention in compact urban morphologies. Second, simulations across multiple LCZs evaluated the cooling potential of incorporating high-albedo materials tailored to specific urban contexts. In LCZ2 (open mid-rise), characterized by intense daytime heat accumulation, road-focused enhancements reduced peak surface temperatures by 2.1°C, with the most significant cooling observed between 10:00–15:00 in August. These findings stress the importance of context-specific strategies: prioritizing road surface modification for daytime heat reduction in open mid-rise zones like LCZ2 while adopting integrated approaches in other LCZs to achieve thermal resilience across varying time scales. This research provides insights for optimizing the application of high-albedo materials across diverse urban climates, offering tailored solutions to improve microclimates and support sustainable urban development.

Keywords: UHI, High-Albedo Surfaces, Local Climate Zone, Thermal Environment, Climate Adaptation Strategies