Spatio-Temporal Urban Expansion Analysıs in a Growing City of Oyo Town ,Oyo State, Nigeria Using Remote Sensing And Geographic Information System (GIS) Tools

Abstract

The assessment of the land use / land cover expansion that occurred in the area over a period of thirty years is the utmost priority of this research work. Multi temporal Landsat satellite imageries TM 1984, 1990 and ETM+ 2002, 2014 from the United States Geological Survey (USGS) website were used as the primary dataset. Area of interest was clipped in ArcGIS 9.3 environment, image enhancement and image classification were adequately done using ENVI 4.5 remote sensing software. Using supervised classification algorithm, the images were classified into bare soil, built-up area, vegetation, water body and wetland; these were then used to carry out change detection analysis or time series analysis. Results obtained from the analysis of built-up area dynamics for the past three decades revealed that the town has been undergoing urban expansion processes. The expansion was prolonged both from urban centre to adjoining non-built-up areas in all directions. The total built up area in the town has expanded from 28.04sq/km in 1984 to 49.51 sq/km in 2014 at an average expansion rate of 0.7, 0.4 and 0.9 per annum during 1984 – 1990, 1990 – 2002 and 2002 – 2014 study periods respectively. The study period from 2002 – 2014 was the time at which the town experienced the highest urban expansion. The analysis of spatial trend revealed that the urban landscape has experienced a process of sprawling and fragmented development pattern particularly in the fringe areas while the town centre underwent infill and edge expansion development processes. The fringe areas show scattered expansion pattern. Quantifying urban expansion patterns and development processes of the past trends can help better understand the dynamics of built up area and guide sustainable urban development planning of the future urban growth.