Effect of land use/cover change on sediment load of the Mpanga river sub-catchment
Abstract
Like other countries in the sub-Saharan Africa, Uganda is not an exception to the effects of
land use/cover changes on the environment. Specifically, the study intended to determine the
effects of land use/cover changes on sediment load in the Mpanga sub-catchment. A series of
images from Landsat and Sentinel acquired for 2000, 2010 and 2020 were classified using a
supervised classification procedure in a 10.4 Geographical Information System software to
determine the land use/cover changes. The Soil and Water Assessment Tool was used to
model the sediment yield in the sub basins of Mpanga micro catchment. Results showed a
variable and increasing trend in expansion of agricultural lands and built-up areas between
2000-2020. Grasslands and wetlands were the most affected land cover types experiencing
the highest level of changes in the study area. Results of projection to 2030 and 2040
revealed that there will be a further increase of agricultural land and built up areas with most
of the expansion occurring at the expense of grasslands and wetlands land cover types. The
pattern of sediment load from 2000-2020 is increasing across the years with 4,161 tonnes and
6,740 tonnes of sediment realised in 2000 and 2020 respectively. There was a variation in
sediment loading taking place across different sub-basins of the Mpanga sub-catchment.
Built-up areas and agricultural lands were the major contributors of sediment loading in the
catchment. This study has therefore shown that land use/cover changes have an effect on
sediment loading in the River Mpanga-sub-catchment. It is recommended that the Ministry of
Agriculture, Animal Industry and Fisheries and the Ministry of Water and Environment as
well as the Ministry of Urban Planning collaboratively promote sustainable agriculture and
urban planning to minimise actions that lead to sediment loading in the catchment.