Balancing Urban Heat, Flood and Water Scarcity: Blue-Green Infrastructure in Alpine Cities 

Abstract

In Alpine cities, water management needs to be adapted to the challenges of climate change, including altering temperature and precipitation patterns. Blue-green infrastructure (i.e., the combination of nature-based and technical solutions) can help to improve the water and energy balance, to increase the evaporative cooling effect, to maintain sufficient soil water availability and to reduce runoff peaks. Thus, it can reduce the risks of heat, drought and flooding, and improve the overall quality of life in cities. The implementation of blue-green infrastructure requires an interdisciplinary approach, as mechanisms of urban water management and ecohydrology (i.e., energy balance and soil-plant-atmosphere continuum) must be optimized with regard to the common goal. In the research project 'BlueGreenCities', ecological and technical disciplines are integrated to close knowledge gaps regarding (1) land-atmosphere interactions in ecological, hydrological and meteorological systems, and (2) the performance of blue-green adaptation measures under different climate scenarios in alpine urban areas. We present first results of measurement campaigns and eco-hydrological modelling to better understand the energy budget of various green spaces in the city of Innsbruck, Austria. Moreover, we give first insights if the specialty of the alpine setting (increasing summer droughts, but still cold winter temperatures) will be a chance or a burden for the current urban vegetation in the future. The outcomes of our project underpin the importance of climate-friendly and future-proof planning of urban green spaces to ensure proper functioning of the blue-green infrastructure concept. The results support scientists as well as urban planners, land developers and policy stakeholders in decision-making for sustainable and flexible water management systems that maintain human well-being, economic development and environmental protection. This work is funded by the Austrian Climate and Energy Fund in the project BlueGreenCities (Project No. KR21KB0K00001), funding period: October 2022 until September 2025.