Land Use Change Detection in OMO Biosphere Reserve Using GIS and Remote Sensing

Abstract

Inadequacy of reliable data on the rate and extent of forest conversion remains a major problem threatening sustainable forest management in Nigeria. In this study, we examined land use change pattern in Omo Biosphere Reserve, Nigeria, between 1987 and 2011. Landsat TM imagery for 1987 and Landsat ETM⁺ imagery for 2011 were analyzed for land use change detection using Erdas Imagine 9.2 and ArcGIS 9.2.  The results showed that farmlands, disturbed forests, settlements and rivers increased in area while the areas covered by the natural forests, plantations, and roads decreased from the 1987 figures. The farmlands had the highest increase in area (19025 hectares) from 1987 figures, followed by disturbed forests (10917 hectares), settlements (4262 hectares), and rivers (235 hectares). The highest reduction in area was observed for plantations (22699 hectares), followed by natural forest (10803 hectares) and roads (937 hectares). As at 1987, the natural forest was the most extensive land cover type, occupying 39.32% of the reserve. However, the disturbed forest is now the most extensive of all the land use types covering 36.34% of the reserve, followed by the natural forest (32.05%), farmland (14.78%), plantation (10.62%), settlement (4.11%), roads (1.22%), and rivers (0.87%). There was a drift in the abundance of the natural forest cover from the northeastern part of the reserve in 1987 to the northwestern part in 2011 due to unsustainable exploitation in the former and various conservation projects in the later. It is expected that the information provided in this study will aid decisions that will enhance sustainable management of the reserve.