Causal Drivers and Future Projections of Urban Wetland Loss in Sunyani East Municipality, Ghana: Implications for Climate Risk and Resilience

Abstract

<title>Abstract</title> Urban wetland degradation in secondary cities of the Global South poses a major threat to ecosystem services and climate resilience, yet causal mechanisms remain poorly understood, especially in inland regions. This study provides a thirty-year (1994–2024) spatiotemporal and causal analysis of wetland loss in Sunyani, Ghana, an inland secondary city. Integrating Landsat imagery, ERA5 climate data, and advanced causal inference techniques Convergent Cross Mapping (CCM) and Geographical CCM (GCCM) we quantified land use/cover change and identified direct drivers of wetland degradation. Results show a severe decline in wetland extent (&gt; 40%), while built-up areas more than doubled. Causal analysis established unidirectional links from urban expansion, agricultural encroachment, and rising land surface temperatures to wetland loss, with precipitation and forest cover as key sustaining factors. Field surveys confirmed widespread conversion, pollution, and hydrological disruption. Future projections indicate wetlands could decline to 1.35% of land area by 2054 under business-as-usual trends, exacerbating flood risk and urban heat island effects. An integrated flood hazard map directly links former wetland areas to high-risk zones. This study demonstrates that wetland loss in Sunyani is a targeted anthropogenic process that amplifies urban climate vulnerability. We recommend enforceable wetland zoning, integration of causal maps into urban planning, and targeted restoration of degraded sites. These findings underscore the urgent need for causal, place-based wetland conservation strategies in rapidly urbanizing tropical regions to ensure the achievement of the Sustainable Development Goals (SDGs), especially Goals 3, 6, 11, 13, and 15.