Urban Expansion and the Sustainability of Land-Use, Environmental and Infrastructure Practices in Lafia Urban Area, Nasarawa State, Nigeria

The rapid physical expansion of Lafia Urban Area, capital of the State of Nasarawa, Nigeria, has heightened demand for land, the environment and infrastructure. This research was carried out to evaluate land-use efficiency, sustainability of the environment and sufficiency of infrastructure to support land use in Lafia Urban Area, in order to determine whether land use in the metropolis is sustainable. A descriptive cross-sectional survey design was employed; with sustainable development theory as its underpinning. The total population of Lafia Local Government Area population was projected to the year 2026, utilizing the geometric growth method with 2.8% annual growth rate obtaining population of 573,157 persons in 2026. Yamane (1967) specified 5% level of precision to obtain a sample size of 400 respondents from a heterogeneous population through stratified sampling. Noticing a low response rate from a 100% distribution, a sample of 399 copies of structured questionnaires which were successfully retrieved; analyzed. Data were derived from the structured questionnaire survey administered to head of households and land users, also observation made in the course of fieldwork. Descriptive statistics (percentages, frequencies, mean scores) were used to produce comprehensive low, moderate and high indices to evaluate land-use efficiency, environmental sustainability and infrastructural sustainability. Land-uses in Lafia Urban Area are characterized by expansion (mean = 4.17), conversion of agricultural/undeveloped land (mean = 4.02) and increasing mixed land use (mean = 4.08), while redevelopment of existing built-up land remains weak (mean = 2.82), producing a moderate land-use efficiency score of 3.18. Environmental sustainability was rated low overall (mean = 2.57), with wetlands and environmentally sensitive areas the least protected (mean = 2.39). Infrastructure sustainability was moderate (mean = 2.75), with drainage and waste management lagging behind road provision. Urban expansion in Lafia is proceeding largely through peripheral conversion of agricultural and environmentally sensitive land rather than through the redevelopment of existing urban land, and this pattern is outpacing the city's environmental protection and infrastructure-coordination capacity. The study recommends an integrated spatial framework that prioritises infill and redevelopment, statutory protection and mapping of green infrastructure and wetlands, and mandatory infrastructure-capacity assessment as a precondition for development approval. The findings extend sustainable development theory to the land-use, environmental and infrastructure interface in a rapidly growing secondary Nigerian city and provide planning authorities in Lafia and comparable urban centres with an empirical basis for prioritising infill development, green-infrastructure protection and infrastructure-linked approvals.