The accelerating pace of high-density urbanization across the Global South has intensified environmental degradation, socio-spatial inequality, and a systemic decline in urban livability. Within contemporary urban planning and landscape architecture, the strategic deployment of Urban Green Space (UGS) and integrated Blue-Green Infrastructure has emerged as a critical socio-ecological instrument for enhancing ecological performance, mitigating structural vulnerabilities, and supporting human well-being. This study presents a multi-criteria comparative analysis of UGS construction, contrasting Chengdu's state-led "Park City" paradigm with Kinshasa's fragmented, predominantly informal urban landscape. Framed within design methodology, this research examines the spatial configurations, structural connectivity, and governance frameworks that determine UGS efficacy. Chengdu's implementation of ecological corridors, interconnected greenways, and sponge city facilities demonstrates how coordinated top-down policy integration and entrepreneurial environmental governance can advance an ecological civilization agenda. Kinshasa, by contrast, faces critical challenges characterized by rapid spatial encroachment, institutional capacity deficits, severe budgetary constraints, and extreme data scarcity. To operationalize cross-continental insights for sub-Saharan Africa while avoiding the pitfalls of uncritical policy borrowing, this paper formulates an adaptive, three-phase strategic framework designated as the "Congo River Park City" model. This path progresses from localized, low-cost environmental mitigation (bioswales and riparian buffer stabilization) to decentralized, community-led infrastructure stewardship, culminating in incremental municipal regulatory and land-use integration. The study demonstrates that while Chengdu illustrates the value of macro-scale ecological connectivity, the long-term viability of UGS systems in Kinshasa fundamentally depends on aligning green infrastructure with the immediate livelihood needs, collaborative co-production capacity, and economic survival strategies of its urban populations.