Challenges created by the Austro-Hungarian Empire: Addressing Urban Heat Inequality through Nature-based Solutions in Vienna and Budapest

Towards the end of the 19th century, dense and urbanized European capitals were developed under the Austro-Hungarian empire. Most of the historically built-up areas are important for cultural heritage, they are now a challenge for heat reduction and urban planning. In Vienna and Budapest, the local populations are facing growing climate change impacts in the form of heatwaves and tropical nights. Nature-based solutions (NBS) are being eyed as measures to tackle urban heat islands and address the unequal distribution of green areas.

The cities of Budapest and Vienna are comparable in terms of geographical area, population and climate zones. The urban morphology of the cities is understood by using Local climate zones to understand the thermal zones formed in the city. Vienna has a higher percentage of compact urban form as compared to Budapest in the city centre. The composition of urban morphology is combined with the results of thermal remote sensing analysis for Urban Heat Island (UHI) using Ecostress and the survey results of an integrated discrete choice experiment for NBS. This study delineated the geographically vulnerable areas and how the most vulnerable people perceive their affectedness. 

In both Budapest and Vienna, heat is felt more intensely and impacts health to a greater extent in low-income neighborhoods with limited access to and poor-quality green areas. However, residents of Budapest stated to have more experience with heat waves and respondents indicated much higher rates of heat negatively affecting them. Budapest reports higher UHI intensity than Vienna - meaning that the difference between perceived heat and actual temperatures is higher in Vienna. Budapest 18th district has been deploying NBS to address extreme heat and flooding. The learnings from the deployment in Budapest and the choice experiment results in terms of preference of NBS feed into suggesting optimum NBS solutions for Vienna.