Urban Heat Island Risk Assessment and Mapping in the Swedish Residential Sector

Abstract

Although Scandinavian countries, including Sweden, are relatively less vulnerable to climate change, Swedish residential dwellings specifically those constructed before the 1975s are likely to be impacted by current extreme weather events (EWE) such as urban heat islands (UHI). This EWE can worsen air quality, increase heat-related illnesses (particularly among vulnerable populations), and raise maintenance costs and energy demand for cooling in buildings.  This study aimed to map UHI risk in Sweden's residential sector using a scenario-based analysis approach. Moderate Resolution Imaging Spectroradiometer (MODIS) Remote sensing (RS) imagery data (land surface temperature (LST)) and some statistical data (including the number of houses, building typologies, and characteristics) collected from the SCB (Statistics Sweden) and TABULA database are used. The overall UHI risk maps for Sweden are developed following the risk matrix approach, by weighting and aggregating the created maps for UHI hazard, building exposure, and vulnerability. Here, the geographical information system ArcGIS pro 3.1 was used to carry out the different spatial analysis tasks, including pre-processing of spatial data, developing required maps, and performing raster calculations. The outcomes reveal a range of areas posing risks, with most high-risk zones situated in the southern and southeastern regions. Moreover, there is a discernible impact of the UHI on most of the buildings across Sweden constructed prior to the 1960s. Nevertheless, for structures built between 1961 to 1975, only those in the southern regions display potential susceptibility to the UHI. Furthermore, the western areas exhibit a low UHI risk. Despite the limitation of data used, the findings of this study have practical implications, as they can help homeowners, renovation companies, and policymakers implement appropriate adaptation strategies. The approach used is comprehensive, easily applicable, scalable, and can be replicated anywhere, assisting in the development of climate-resilient buildings not only in Sweden but also in other regions.