Land Use Land Cover Changes and Its drivers in Gojeb River Catchment, Omo Gibe Basin, Ethiopia

Abstract

Land use land cover (LULC) changes are inherently spatial and dynamic with high spatiotemporal variability resulted from complex human-environmental interactions. Current extents, rates and intensities of LULC changes are driving unprecedented changes in ecosystems functions and environmental processes at local, regional and global scales. The study was conducted to assess LULC changes and its drivers using remote sensing (RS) and geographic information system (GIS) in Gojeb River Catchment, Ethiopia. The satellite images at different reference years (1978, 1987, 2001 and 2015) were obtained from Landsat images. Supervised classification with maximum likelihood algorithm was applied for image processing and change analysis. The LULC classes identified were cropland, forestland, shrubland, swamp, and woodland. The study found that the catchment has undergone significant LULC changes. The major changes were expansion of cropland at the expense of other LULC classes at the rate of 29.56% in 1978, 38.91% in 1987, 46.62% in 2001 and 52.74% in 2015. It has gained about 160,736.08 ha with an annual average increment of 4,344.22 ha. Conversely, forestland has undergone reductions at an annual rate of 9,030.0 ha between 1978 and 1987. The conversions of other classes to cropland are mainly associated with more demand for crop production. On the other hand, the conversion of relevant part of forest land to other classes could be due to vegetation degradation. Hence, the conversion of forestland to other land use classes could be attributed to the highly demand of agricultural land, firewood, charcoal, timbers and housing materials. The major driving forces which should be considered in sustainable watershed management were population growth and government induced settlements. Provision of modern alternative sources of energy, agricultural inputs and promoting non-agricultural sectors are also other considerations for the community sustainable livelihood. It is critical to follow holistic view and management of the catchment for successful integrated watershed management endeavours.