Analysis of the Pattern of Land Degradation in Okaba, Kogi State, Nigeria

Abstract

The study examined the pattern of land degradation in Okaba using GIS and remote sensing techniques. The study area is located between latitude 7 25’7 31’N and Longitude7 40’7 46′ E and covers approximately 122.7km2. The satellite data (landsat: 1998, 2002, 2007and 2012) together with other geospatial datasets were used to quantify different categories of land degradation. The results were validated in the field. Land use/ land cover of the study area was determined in order to see the effects of land use on land degradation. Normalized Differential Vegetation Index (NDVI) and Tasseled Cap indicators of the area were determined from Landsat data. Landsat along with other secondary data were analyzed to create various thematic maps, viz., land use, vegetation, and soil used in modeling land degradation in Okaba. The Land use/cover, NDVI, Tasseled Cap Brightness (TCB), Tasseled Cap Wetness (TCW) and Tasseled Cap Greenness (TCG) were integrated to assess the degradation scenario in the study area using the Idrisi Selva ‘Reclasstool’ and ArcGIS 10’Spatial analyst tool’. The results reveal that bareground increases throughout the study epoch while vegetation decreases. The findings of this study revealed that 42.1% of land is undergoing different categories of land degradation such as soil erosion and devegetation.