On Tuesday, October 28, 2025, an FGD was held in the BAPPEDA Meeting Room of Malang City, with the title “Intervention Model of Urban Heat Island (UHI) Mitigation Simulation Based on Computational Fluid Dynamics (CFD) in the Buffer Zone of Urban Cultural Heritage Areas.” This activity is part of research led by Prof. Ir. Respati Wikantiyoso, MSA, Ph.D. The DRPM Ministry of Higher Education, Research, Science, and Technology funded this research for the 2025 fiscal year. The implementation in the BAPPEDA Meeting Room of Malang City is a form of BAPPEDA Malang City’s commitment as a partner of the city government in this research. This FGD event presented speakers from BAPPEDA and the Environmental Agency of Malang City. Ten related agencies are attending this event, including BBWS, Perum Jasa Tirta, and BPBD Malang City. Actually, this FGD was the first, followed by a second FGD in early December 2025 at the exact location. The discussion will focus on CFD simulation results and their potential for UHI mitigation in the Kayutangan Heritage Area.
Global warming and rapid urbanisation have exacerbated the Urban Heat Island (UHI) phenomenon, characterised by increased temperatures in urban areas compared to surrounding areas. UHI is not simply a physical phenomenon in metropolitan areas but also has profound implications for the quality of life of urban residents. In addition to increasing ambient temperatures, UHI also contributes to reduced thermal comfort, increased energy consumption due to more intensive air conditioning use, and increased health risks, especially for vulnerable groups. The limitations in structural and material modifications hinder the implementation of conventional solutions for UHI mitigation. A simulation-based approach is necessary to evaluate mitigation strategies comprehensively. One of the most advanced methods for this analysis is Computational Fluid Dynamics (CFD)-based modelling, which enables high-resolution simulations of heat transfer and airflow with greater accuracy than other models.
In urban environments, three main mechanisms are involved in heat transfer and airflow: conduction, convection, and radiation. Conduction occurs when heat moves through building materials, depending on the material’s thermal conductivity. On the other hand, it involves heat transfer through a fluid, in this case, urban air, which can be affected by building geometry and wind speed. Radiation is the primary mechanism of surface heating, involving the interaction between solar radiation and building surfaces that have different optical properties, such as albedo and emissivity.
A case study in the Kayutangan urban cultural heritage area in Malang revealed that this area experiences significant temperature increases due to high building density, minimal green open space, and the dominance of low-albedo pavement surfaces. In the first step of this research, it was shown that temperatures in the Kayutangan area can reach 3-5°C higher than in surrounding suburban areas during the day. Another factor exacerbating this situation is the limitation on building structural modifications due to regulations related to the preservation of cultural heritage areas. Therefore, UHI mitigation in this area requires an approach that considers not only technical effectiveness but also historical and conservation aspects. Based on the explanation above, UHI mitigation strategies have been developed, including the application of reflective surfaces, green roofs, and increased green open spaces. However, in urban heritage areas, implementing these strategies often faces challenges related to aesthetics, conservation regulations, and space constraints.
Detailed heat distribution and airflow patterns in urban environments can be analysed using CFD simulations before physical implementation. This significantly contributes to more effective and efficient urban heritage planning. CFD simulations provide a simulation-based approach for evaluating proposed development plans in heritage areas. In the context of buffer zones in urban heritage areas, CFD can be used to dynamically simulate changes in temperature and airflow, providing a more accurate picture of the impact of various mitigation strategies.