Assessment of Urban Sprawl in Mowe/Ibafo Axis of Ogun State using GIS Capabilities

Abstract: Urban Sprawl is one of the challenges to urban development in many nations. Different aspects of the phenomenon have been researched with a view to providing solutions to myriad of ills attributed to it. For any meaningful intervention, however, assessment of development to ascertain sprawl is essential. Despite this, its quantification and monitoring in environment with paucity of data remains a daunting task. Therefore, this thesis was designed to utilise GIS to assess urban sprawl in Mowe/Ibafo area of Ogun State. The study classified Landsat data of 1987, 2000 and 2016 covering Mowe/Ibafo into water, vegetation and built-up areas and subjected them to post classification analysis. Digital Elevation Model and population data were used to examine factors of urban expansion and staff of Planning Offices interviewed to obtain data on development monitoring. The classified land cover map was divided into zones using centre of the towns and expressway. Shannon’s Entropy and Relative Entropy were computed from the zones. Elevation layer was also overlaid on the classified land cover map to examine factors of expansion. Overall Accuracy assessment for 1987, 2000 and 2016 classification were 88%, 90% and 86%. The classification showed that 1.69% (5.52 sq.km) of Mowe/Ibafo was built in 1987. This increased to 8.33% and 66.26% in 2000 and 2016 respectively. The results of a paired-samples t-test conducted revealed a significant difference between 1987 and 2016 land cover scores with an increase from 1987 (M = 2.0115, SD =0.14899) to 2016 (M = 2.3116, SD = 0.49023), t(362079) = -36.801, p <.0005). The results of Relative Entropy were very high and close to 1 confirming urban sprawl in Mowe/Ibafo. A comparison with Entropy values for the area within Obafemi-Owode (subset of the study area) produced a lower value, though close to 1, suggesting that the wider the coverage, the more the magnitude of sprawl. Pattern of development in the area was influenced by expressway and elevation as flat and stable (15 – 30 m) areas were most developed. The study revealed that there was inadequate local manpower,resources and government synergy to adequately monitor development in the area. The government of Ogun and Lagos states should work together for orderly development of Mowe/Ibafo axis.