Abstract

This research is an attempt to assess the deforestation rate that took place during the period from 1986 to 2002 in the ILESHA region of southwestern Nigeria. The study used two multi-date Landsat images P190R55 for the years 1986 and 2002, in addition to a topographic map at a scale of 1:250,000 covering ILESHA area (produced and published by Federal Surveys, Nigeria, 1969).

The Topographic map and the two images (after transforming the former to a Digital Raster Graphic "DRG" using an A4-sized scanner) were processed and analyzed. The results showed that the annual rate of depletion of the humid tropical rainforest cover during the period from 1986 to 2002 was -1.85% (equivalent to 11,823.5 ha). The increase of the areas covered by derived savanna (+185%) and disturbed secondary forests (+1.42%) at the expense of the area covered by humid tropical rainforests was attributed to the intensity of agricultural activities necessitated by the increase of population. The increase of population was manifested by the increase of the area covered by settlements (+2.80%).

The annual depletion rate of water bodies (-2.34%) also contributed to the humid tropical rainforest deforestation rate.This research underscores the advantages of integrating space-based earth observation technologies (RS, GIS, and GPS) for the continuous forest inventory and monitoring.It was found out that if current deforestation rate is not controlled, the humid tropical rainforest in the study area will be completely depleted within 38 years from 2002.