Green infrastructure investment prioritization for urban ecosystem services and resilience: a decision-support framework

Green infrastructure (GI) investments are increasingly promoted as nature-based solutions that generate multiple ecosystem services and contribute to human well-being, climate adaptation, and urban resilience. However, prioritizing GI alternatives is a complex decision problem because different options provide diverse regulating, maintenance/habitat-related, cultural, ecological, technical, and socio-economic benefits under uncertainty. To provide a systematic ecosystem services basis, this study uses the Common International Classification of Ecosystem Services (CICES) as a guiding reference for screening the potential contributions of urban GI alternatives to human well-being. In particular, GI alternatives can be understood as ecosystem service bundles, where interactions and potential synergies among water regulation, biodiversity support, urban cooling, recreation, and public well-being shape their overall contribution to ecosystem management. To address this challenge, this study proposes an integrated Multi criteria Decision Aiding (MCDA) framework for prioritizing GI investment alternatives under uncertainty. The proposed framework combines the Modified Delphi approach, Intuitionistic Fuzzy Step-wise Weight Assessment Ratio Analysis (IF-SWARA), and Intuitionistic Fuzzy Multi-Attributive Border Approximation Area Comparison (IF-MABAC). The Modified Delphi approach is used to validate the criteria and alternatives and consolidate expert judgments, while IF-SWARA determines the relative importance of the evaluation criteria. IF-MABAC is then applied to rank GI investment alternatives. The findings show that Stormwater Management and Flood Mitigation receives the highest criterion weight (0.080), although the overall weight distribution is relatively balanced across the fifteen criteria. Following the IF-MABAC calculation, Constructed Wetlands emerge as the highest-ranked alternative (1.183), followed by Green Walls (0.309), Rain Gardens (0.173), Green Roofs (0.031), and Permeable Pavements (-0.220). Constructed Wetlands show positive relative performance on 12 of the 15 criteria, although trade-offs remain for cost-effectiveness, long-term replacement cost, and technical feasibility. The robustness analyses consistently preserve Constructed Wetlands as the leading alternative, while greater variation is observed among the lower-ranked options. The resulting prioritization is expert-based and context-specific and should therefore be interpreted as conditional on the selected criteria structure, consensus judgments, linguistic scale, and Kayseri planning context. Ultimately, the study contributes to ecosystem services research by offering a CICES-informed, transparent criteria architecture for supporting GI investment decisions rather than a purely methodological innovation.