Evaluating the Social Sustainability of Urban Blue-Green Infrastructure: A Visual Perception Study on the Restorative Capacity of Public Spaces

As a core tenet of Green Urbanism, fostering social sustainability through restorative urban environments is essential for enhancing the psychological resilience of active urban generations. While urban parks are recognized as critical blue-green infrastructure, the micro-mechanisms through which their morphological configurations influence perceived restoration remain insufficiently understood. The aim of this study is to investigate how specific landscape element types and proportions in urban parks modulate the visual behavior and psychological restorative outcomes of young urban populations through a multimodal experimental approach. This study employs a novel assessment framework, integrating VR-based eye-tracking and physiological monitoring (HRV, EDA, EEG), with a sample of 77 young adults (aged 18–30) to investigate how landscape element types and proportions modulate visual behavior and restorative outcomes. The findings indicate that landscape components drive restoration through divergent visual cognitive pathways: natural elements promote recovery by fostering sustained visual engagement and exploratory saccades, whereas artificial elements function as cognitive stressors that fragment visual continuity. Mediation analysis further reveals a “quality-over-quantity” effect, demonstrating that restorative efficacy is governed by specific morphological configurations rather than mere green coverage. We identify critical restorative thresholds where the systematic reduction in artificial visibility, combined with the strategic prioritization of multi-layered vegetation and optimized sky openness, significantly maximizes restorative fascination and physiological relaxation. These evidence-based design strategies offer a precise toolkit for sustainable urban renewal, allowing urban planners to optimize the restorative quality of public spaces. By aligning micro-scale visual perception with macro-scale social sustainability goals, this research contributes to the development of resilient and health-promoting cities under the principles of Green Urbanism.