Land use/landcover change detection mapping of Apa local government area, Benue state, Nigeria

Abstract

The study was carried out to detect the changes in land use/landcover of Apa Local Government Area of Benue State. Many researches have been carried out on land use/land cover mapping in urban areas in Nigeria, however only few have been carried out in rural areas. This study therefore, was geared towards identifying the land use/land cover changes over the years in Apa Local Government Area of Benue State, Nigeria using satellite remotely sensed data, and determining the magnitude and rate of change over the years. For the study, Landsat satellite images were acquired for 1986 and 2001 while Nigeriasat-x was used for 2012. Images were subjected to various image processing techniques and a supervised classification was carried out on the various images using ILWIS (Integrated land and water information system) software. The classification resulted in six classes which include bare surfaces, cultivated area, urban area, forest, grassland and Water body. The result showed that during the 26 years period, the magnitude of change of forest area was -144.985km2, percentage of change was -70.75% and annual frequency of change was -5.58km2; cultivated area had a magnitude of 208.041km2, percentage of change was 97.04% and annual frequency of change was 8.00km2; the magnitude of change of urban area was 14.177km2, percentage of change was 15.43% and annual frequency of change was 0.55km2; grassland in the study area also has a magnitude of change 54.63km2, percentage of change was 18.61% and annual frequency of change was 2.10km2. The study further revealed that loss of naturally vegetated area was mainly as a result of urban growth and expansion, farming activities and commercial activities. Land cover of the study area during the period between 1986 and 2012 changed from a forested area to other land uses as a result of increase in population, demand for land for agricultural purposes and increase in the demand for firewood. In order to curb the increasing rate of deforestation in the study areas, the study therefore recommends that, government at all levels should enforce existing laws/sanctions policies against activities that lead to deforestation like indiscriminate felling of tress, bush burning and illegal logging of trees.

Keywords: Land use/land cover changes, remotely sensed data, Nigeriasat-X, ILWIS, image processing, supervised classification and deforestation.