Monitoring Urban Sprawl in the Federal Capital Territory of Nigeria Using Remote Sensing and GIS Techniques

Abstract

Urbanization in Abuja and its environs was largely due to the movement of the Federal Capital Territory to Abuja in 1991 causing the influx of internal/national and international migrants and natural increase of birth rate over mortality. This increase has not only put pressure on the city (Abuja) but the surrounding settlements by posing a threat to the limited resources thereby resulting to high cost of living. Abuja city was planned for limited people as opposed to what is obtained now. The research set out to measure the changes in landmass or landuse/landcover and population increase in the study area. Multi-date Satellite images of 1987, 1999 and 2007 (Landsat TM, Landsat ETM and Nigeriasat 1) were acquired from National Centre for Remote sensing Jos and used in analyzing the physical expansion of the city overtime. Using supervised classification algorithm, the images were classified into built up, rock-outcrop, vegetation and water bodies and used to carry out change detection or time series analysis. In addition, coordinates of locations in the area were obtained using a GPS while figures from National Population Commission were used. Change detection analysis was carried out on the imageries to obtain the physical expansion of the area. Using change detection method, it was found that the builtup area increased from 8% in 1987 to 22% in 2007, rock-outcrop decreased from 74% to 37%, vegetation decreased from 40% to 17%, while the area occupied by water body has remained constant overtime. Also projection was done for population in the next nine years and 1,925,464.089 figures which are about 37% is expected. To support this increase in population and physical growth rate observed, constant monitoring of the urban growth is required to be sustained by anthropogenic activities.

Key words: Monitoring, Urban sprawl, Urbanization, Remote Sensing, Geographic Information System (GIS), change detection