Enhancing urban sustainability: An emergy-based framework to support green infrastructure planning

Highlights • Develop a sustainability-oriented optimization framework for GI planning. • The framework has high universality and low data requirements. • Provide novel insights from a perspective of energy for GI projects. • Achieve unbiased and equitable cross-domain evaluation of GI’s multifunctionality. • Prevent overdesign and reduce net energy consumption in GI projects. Green infrastructure (GI) is a vital strategy for climate change adaptation and urban sustainability, yet integrating its multifunctionality remains significantly challenging. This study develops a sustainability-oriented optimization framework for GI systems, incorporating emergy analysis, multi-objective optimization, and regional climate models. It highlights a sound cross-domain assessment and addresses real-world challenges such as limited data availability and tight timelines. This framework is applied to two cases across different countries and reveals that GI project sustainability varies by site-specific factors and national contexts. Common findings underscore the high priority of green roofs, which, combined with rain gardens or sunken greens, are eco-friendly, cost-effective, and multifunctional. Permeable pavements, despite previous economic advantages, show lower sustainability. Sensitivity analysis reveals the importance of parameters related to green roofs and the emergy money ratio. This research provides robust decision support for stakeholders and advances GI planning, offering novel insights into sustainable urban practices under climate change.