Abstract:
In an effort to pinpoint the sources of sediment pollution in Lake Victoria, the contribution of sediment from
compounds, landing sites, unpaved roads and footpaths is determined in the catchment of Nabera Bay and
Kafunda Bay at the northern shore of Lake Victoria in southern Uganda. The volume of soil loss is determined
in 36 compounds, 1 school and 1 landing site by comparing the original and current soil surface. The original
soil surface is reconstructed using botanical and man-made datable objects. The soil loss rates are calculated
by dividing the eroded soil volume by the age of the oldest datable object. Considering all compounds and
landing sites in the study area, the average soil loss rate in compounds amounts to 107 Mg ha−1 year−1 (per
unit compound) and to 207 Mg ha−1 year−1 per unit landing site. The soil loss from footpaths and unpaved
roads is calculated by multiplying the total length of footpaths and unpaved roads with the average width and
soil loss depth. The mean soil loss rate on footpaths is 34 Mg ha−1 year−1 and on unpaved roads equals
35 Mg ha−1 year−1. Compounds, landing sites, footpaths and unpaved roads occupy a small fraction of the
study area (2.2%), but contribute disproportionately to the total soil loss (i.e. 85%) in the study area. It is
concluded that compounds, landing sites, footpaths and unpaved roads are very significant sources of
sediment pollution to Lake Victoria. This needs to be considered when designing strategies to reduce
sediment production in the area.
