Urban Sprawl and Traffic-Related Air Pollution in Greater Gaborone: A Spatial Analysis of the Land Use–Transport–Environment Relationship

Keone Kelobonye , Chenesani Sithole, Orateng Amos

Rapid urban sprawl in many Sub-Saharan African cities has significantly reshaped urban mobility patterns, resulting in longer commuting distances, increased private vehicle dependence, and growing pressure on major transport corridors. These trends have important implications for environmental quality, urban sustainability, and climate resilience. This paper investigates the spatial relationship between urban sprawl and traffic-related air pollution (TRAP) in Greater Gaborone, Botswana, using Geographic Information Systems (GIS) and remote sensing techniques. Landsat imagery from the United States Geological Survey (USGS), accessed via Google Earth Engine, is used to map land use and land cover change between 2006 and 2026, and Sentinel-5P TROPOMI tropospheric NO2 data are used to map TRAP hotspots for 2026 using the Getis-Ord Gi* statistic. Built-up land area in Greater Gaborone grew by 79.6% over the study period, spreading outward from the historic core in multiple directions. TRAP hotspots are concentrated in this core and extend along the city's major roads into nearby growth areas, while more distant peripheral growth remains in the coldspot zone. This suggests that pollution has not spread uniformly with the built-up footprint, and that Greater Gaborone's transport corridors may play a role in shaping which growth areas experience elevated pollution and which do not. These findings offer evidence-based insights for land use planning and air quality management within Botswana's urban development framework, and highlight that Greater Gaborone spans multiple local government jurisdictions with no single authority responsible for the metropolitan area as a whole.