A SURVEY OF LAND USE CHANGES IN ARABLE SOILS IN THE SOUTH-WESTERN CORNER OF UGANDA
Mutekanga F. P. N.
Uganda Polytechnic Kyambogo, Department of Physics, P.O. Box 7181, Kampala, Uganda. Email: mtekanga@afsat.com
Accepted in January 2004
Abstract
The majority of the population in Uganda depend on agriculture for their livelihood, yet agricultural production is being very strongly affected by land degradation. There is, therefore, an urgent need for sustainable management of the land resources. Sustainable management depends on effective decision-making and a requirement for this is up-to-date information on the extent and severity of degradation. This study, carried out in Bubale sub county, Kabale District in the southwestern corner of Uganda, was aimed at assessing the extent and severity of land degradation in the district, information of which would be used in decision-making for natural resource management and land use planning in the district. Soil degradation was investigated using remote sensing and GIS techniques. Aerial photographs of the years 1954 and 1990 were interpreted for three parishes in the sub county, namely, Kashenyi, Nangara and Nyamiyaga and a land cover change analysis was made. Features of soil degradation were examined on four hill slopes: Kitumbeezi-Rwenkunguru, Kafunjo, Kabindi and Rwamate, representing the East, West, South and North respectively. The features examined were soil chemical characteristics and erosion features. The interpretation of the aerial photographs revealed only the different classes of land cover and not the features of erosion. Erosion features in Bubale sub county are not very extensive and could only be observed on the ground. From the land cover change analysis it was observed that the cultivated area and that under grassland decreased appreciably between 1954 and 1990 while that of settled area and woodlots increased. The cultivated area was turned to settlements due to increased population and to woodlots because it could yield no more. The grasslands, which were actually marginal land, were converted to cultivated area due to the demand for more arable land. Land degradation was observed to be responsible for declining yields, which was reported to be about half to two thirds of what they were during the 1970s. Erosion features were in form of rills, alternating scours and sediment fans, pedestals, collapsed terrace bunds and gullies.