Detecting and Monitoring Desertification Indicators in Yobe State, Nigeria
E. Elijah; M. Ikusemoran; K. J. Nyanganji and H. U. Mshelisa
Journal Title:Journal of Environmental Issues and Agriculture in Developing Countries
Owing to the environmental and socio economic impacts of desertification in Yobe State, this work sets out to detect the indicators of desertification in the study area and to monitor their spatio-temporal changes from 1975 to 2013. Five multi-temporal Landsat satellite imageries within the same season (OctoberNovember) of 1975 (from Landsat Multispectral Scanner (MSS), 1986 (from Thematic Mapper (TM)), 2000 and 2009 (from Enhanced Thematic Mapper (ETM+)) and 2013 was acquired from Earth Explorer by Google Earth Pro maps were used for this study. The acquired images were classified into four landcover types: surface water, trees, shrubs/grass and bare land/dunes. The result shows that the percentage of surface water recorded about 0.51% decrease between 1975 and 2013, the trees landcover class decreased from 582.76km2 in 1975 to 284.73km2 of the total land area in 2013, area covered by shrubs and grass also decreased from 1990.45km2 in 1975 to 669.06km2 in 2013. Dryland areas covered by bare land and dunes increased from 5061.25km2 to 6719.74km2 in 1975 and 2013 respectively at a rate of 43.64km2 annually. The results of the spatial distribution pattern of physical and biological indicators of desertification were used to establish the presence and spatial coverage of desertification in the study area. Assessment of area coverage of a selected dune at the northern part of the study area using Google Earth Pro map reveals that the dune increased from 0.19km2 in 2010 to 0.21km2 in 2013. From these findings, constant monitoring and evaluation of areas affected by desertification and effective community-based tree planting programme is recommended among others.