Dynamics of land use and land cover change in semi-arid Karamoja sub-region, Uganda

There is limited information on the patterns of land use and land cover changes taking place in the semi-arid ecosystem of Karamoja, a key livestock producing sub-region of Uganda. Thus, this study was designed to determine the pattern and rate of land use and land cover changes in Karamoja sub-region. The study was retrospective using Landsat imagery for 1986, 2000 and 2013. Imagery was obtained from the Global Observatory for Ecosystem Service and analysed using unsupervised classification in ERDAS IMAGINE 9.1 and ArcGIS 10.1. Satellite image overlays were conducted in order to determine the patterns of land use and land cover change. Results showed that grasslands remained the dominant land cover type, however, a declining trend from 75.8, 74.2 to 66% during 1986, 2000 and 2013 period, respectively, were observed. The decline in grasslands is orchestrated by an increase in bushland and croplands over the same period. Croplands increased ten-fold between 2000 and 2013 arising from increased promotional activities by government of Uganda and development actors in the sub-region. Land use and land cover change matrix revealed varied dynamics of change in different land use and land cover types. Between 1986 and 2013, 98.7% of woodlands converted to other land use/cover types. During the same period, 59.3% of grasslands converted to bushlands and 35.8% of croplands converted to thicket and shrublands. We have shown that bushland encroachment and cropland expansion present a real challenge to the continued existence of key grazing land covers in the rangelands of Karamoja.