Green infrastructure implementation for sustainable stormwater management in urban environments: a configurational approach

With the impending consequences of climate change, increased urbanization, and the proliferation of impermeable surfaces, the need for sustainable stormwater management (SSM) is more critical than ever. This urgency has driven the adoption of nature-based solutions, such as green infrastructure (GI) implementation, which has proven to be both efficient and effective for managing stormwater sustainably. However, the implementation of GI faces several barriers, necessitating a closer examination of the key factors driving its adoption. This study aimed to identify the combination of GI factors that lead to SSM. Through a review of the literature focusing on GI for stormwater management, as well as a review of the literature on SSM we identified four GI factors (Appendix A) that are contributing to the outcome of SSM: stakeholder engagement, financial incentives, regulatory policies, and technical considerations. Existing studies show how certain GI factors can lead to SSM without explaining how these factors combine. Our study responds to this gap by following the QCA method, in order to explain how the different GI factors combine for SSM in urban environments. The objective of this research will therefore be to answer the question: what are the combinations of green infrastructure factors that lead to sustainable stormwater management in urban environments? To achieve this, a fsQCA (fuzzy-set Qualitative Comparative Analysis) was conducted using 16 case studies (Appendix B) to gain insights into real-world applications. After data calibration (Appendix C), necessary conditions (Appendix D) and truth table analysis (Appendix E), the FsQCA findings (Appendix F) reveal two configurations for sustainable stormwater management in urban environments. High levels of stakeholder engagement and regulatory policies are present in both configurations. However, these modalities are necessary but not sufficient for achieving SSM in urban environments; it is meaningful only when combined with financial incentives (Configuration 1) or with technical considerations (Configuration 2). While stakeholder engagement and regulatory policies and regulations are crucial, the study also underscores the importance of financial incentives and technical considerations. These factors have been identified as significant barriers in many studies and must be addressed to overcome the challenges associated with green infrastructure implementation. Addressing these complexities, particularly technical considerations and financial constraints will foster more sustainable urban environments that are resilient to stormwater challenges