Abstract. This study assesses decentralised blue-green infrastructure measures for urban climate adaptation in Berlin and Cologne using a dual approach that combines multi-criteria analysis and cost–benefit analysis. Twenty sustainable urban drainage system variants, including swales, trenches, tree pits, green roofs, and cisterns, are evaluated with respect to economic, social, environmental, and hydrological performance. Results show that vegetated measures, particularly swales and tree-based systems, achieve the highest overall scores and positive net-benefit values, while predominantly underground systems perform less well. The integrated assessment highlights important co-benefits and trade-offs of blue-green infrastructure and provides decision support for prioritising nature-based solutions in urban rainwater management.
Received: 22 Dec 2025 – Discussion started: 20 Jan 2026
Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
Cities face more heat and extreme rainfall. We studied twenty blue-green infrastructure options, such as swales, green roofs and tree pits. Using a multi-criteria assessment and a cost-benefit evaluation, we found that vegetated measures deliver the most benefits, while underground systems score lower. Our results suggest cities should prioritise solutions with green elements that effectively reduce flooding, support cooling and improve urban well-being.
Cities face more heat and extreme rainfall. We studied twenty blue-green infrastructure options,...
