Spatial modelling of summer climate indices based on local climate zones: expected changes in the future climate of Brno, Czech Republic

摘要

With global climate change ongoing, there is growing concern about future living conditions in urban areas. This contribution presents the modelled spatial distribution of two daytime (summer days, hot days), and two night-time (warm nights and tropical nights) summer climate indices in the recent and future climate of the urban environment of Brno, Czech Republic, within the framework of local climate zones (LCZs). The thermodynamic MUKLIMO_3 model combined with the CUBOID method is used for spatial modelling. Climate indices are calculated from measurements over three periods (1961-1990, 1971-2000 and 1981-2010). The EURO-CORDEX database for two periods (2021-2050 and 2071-2100) and three representative concentration pathway (RCP) scenarios (2.6, 4.5 and 8.5) are employed to indicate future climate. The results show that the values of summer climate indices will significantly increase in the twenty-first century. In all LCZs, the increase per RCP 8.5 scenario is substantially more pronounced than scenarios per RCP 2.6 and 4.5. Our results indicate that a higher absolute increment in the number of hot days, warm nights and tropical nights is to be expected in already warmer, densely populated midrise and/or compact developments (LCZs 2, 3 and 5) in contrast to a substantially lower increment for forested areas (LCZ A). Considering the projected growth of summer climate indices and the profound differences that exist between LCZs, this study draws urgent attention to the importance of urban planning that works towards moderating the increasing heat stress in central European cities.