Souverijns Niels, De Ridder Koen, Veldeman Nele, Lefebre Filip, Kusambiza-Kiingi Frederick, Memela Wetu, Jones Nicholas K W
Environmental Modeling Unit, Flemish Institute for Technological Research (VITO), Mol, Belgium.
PlanAct, Johannesburg, South Africa.
Urban Clim. 2022 Dec;46:101331. doi: 10.1016/j.uclim.2022.101331.
Heat stress is an important threat for human health and urban areas are affected at higher rates compared to rural environments. Additionally, climate change will increase the vulnerability towards urban heat stress in the future. Current high-resolution urban heat stress assessments are limited in time and space due to the high computational costs. In this paper, the UrbClim numerical model is used to simulate urban heat accurately at a fast rate and high spatial resolution for the cities of Johannesburg and Ekurhuleni, South Africa. Using detailed terrain information, (future) urban heat stress assessments are provided at 30 m resolution for both city agglomerations, while meter-scale simulations are executed for a selection of neighborhoods. These model simulations are evaluated using an extensive monitoring campaign in which the local community was heavily engaged. Distinct spatial differences in the urban heat island effect are observed, with greatest heat stress in areas with high building densities and low vegetation numbers. These areas are often characterized by lower socio-economic living conditions. The meter-scale analysis further shows the importance of shade provided by vegetation to lower heat stress in both present and future climate. These assessments offer assistance in the design of climate-resilient urban planning strategies.
热应激是对人类健康的一项重要威胁，与农村环境相比，城市地区受影响的比例更高。此外，气候变化将在未来增加城市热应激的脆弱性。由于计算成本高昂，当前的高分辨率城市热应激评估在时间和空间上受到限制。在本文中，UrbClim数值模型被用于快速且以高空间分辨率准确模拟南非约翰内斯堡市和埃库鲁莱尼市的城市热状况。利用详细的地形信息，为这两个城市群提供了30米分辨率的（未来）城市热应激评估，同时对部分社区进行了米级模拟。这些模型模拟通过一项广泛的监测活动进行评估，当地社区深度参与其中。观察到城市热岛效应存在明显的空间差异，在建筑密度高、植被数量少的地区热应激最为严重。这些地区往往具有较低的社会经济生活条件。米级分析进一步表明，植被提供的遮荫对于降低当前和未来气候下的热应激都很重要。这些评估为气候适应型城市规划策略的设计提供了帮助。
