Speaker
Description
Blue-green infrastructure (BGI) have been lauded as a multifunctional solution for cities since they can simultaneously contribute to stormwater management, heat mitigation, and biodiversity conservation. However, deciding on BGI elements, such as green roofs or ponds, which perform different functions, is complex. Elements are interconnected, can be combined, their performance is uncertain, and societal preferences about the desired function also vary.
This study tackles the complexity and uncertainty of assessing BGI combinations with respect to 13 technical, social, environmental and economic objectives using participatory multicriteria decision analysis (MCDA). We assessed 61 combinations of green roofs, bioretention cells, detention ponds, and pervious pavement at different implementation rates (10%, 25%, 50% and 100%) in a municipality near Zurich, Switzerland. Using multi-attribute utility theory (MAUT) and the concept of expected expected utility (EEU), we integrated probabilistic performance predictions from domain-specific models with expert judgement and elicited preferences of six local stakeholders. EEU provides a rationale to select options when predicted performance and preference data is probabilistic.
Overall, bioretention cells combined with detention ponds performed well in face of heterogeneous stakeholder preferences, indicating potential compromise. Smaller implementation rates performed better than larger spatial coverage because the higher associated drawbacks, e.g., costs and potential for invasive species outweighed marginal performance gains of larger coverage. For the first time, this work conducts a systematic sustainability assessment of BGI by a participatory, model-informed approach, enabling robust recommendations for urban planners and decision-makers. We show that a comprehensive participatory approach, involving real-world stakeholders, is essential to the robustness of these recommendations.
| Keywords | multi-attribute; utility theory; uncertainty analysis; participatory MCDA; sustainable infrastructure; nature-based solutions |
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| Participation in the SNSF Early-Stage Researcher Support and Award Scheme | I am submitting a regular presentation but do not wish to participate in the scheme. |
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