Urban Expansion and Its Dual Impact on Biodiversity Loss and Thermal Dynamics: A Remote Sensing-Based Assessment of Abomey-Calavi, Benin

Rapid urban expansion in sub-Saharan Africa has increasingly posed challenges to ecological sustainability and climatic stability.In this study, the spatiotemporal impacts of urban growth on biodiversity and surface temperature dynamics in Abomey-Calavi, Republic of Benin, were quantitatively assessed.A multidecadal analysis was conducted using satellite imagery from the Landsat series (1992, 2002, 2012, and 2022), temperature records, and relevant literature, in alignment with Sustainable Development Goal (SDG) Indicator 11.3.1 and Indicator 1 of the Singapore City Biodiversity Index (CBI).Findings revealed a significant imbalance between land consumption and population growth, with a land use to population ratio of 4.25, substantially exceeding the sustainable threshold of 1.This trend denotes unsustainable urban development.Concurrently, biologically active land-serving as a proxy for biodiversity-declined from 472.42 km (94.75% of the study area) in 1992 to 220.31 km (44.19%) in 2022, amounting to a biodiversity area loss exceeding 50%.Thermal analysis detected statistically significant shifts in both minimum and maximum temperatures, with minimum temperatures increasing from 24.41 to 25.14 (p = 3.14 10) and maximum temperatures rising from 30.30 to 31.02 (p = 7.62 10).These findings indicate that urban sprawl has not only driven ecological degradation through habitat fragmentation and biodiversity depletion but has also exacerbated the urban heat island effect.The methodological integration of geospatial analysis, climate data, and urban biodiversity indicators demonstrates the utility of multidisciplinary approaches in diagnosing the environmental consequences of unregulated urbanization.The results underscore an urgent need for evidence-based urban planning and biodiversity-sensitive development policies tailored to rapidly expanding West African cities.