SOIL-EROSION SURVEY OF THE CENTRAL PART OF THE SWAZILAND MIDDLEVELD

Soil erosion has worsened considerably in the Middleveld of Swaziland over the last 20 years. Most of the erosion has occurred on deep collu vial and saprolitic materials and is associated with convex-slope brea ks and rejuvenation shoulders on valley sides. Although the risk of er osion seems to reflect natural instability in the landscape, the way i n which the land is used determines the ultimate severity of the probl em. Land systems can serve as functional units as far as erosion asses sment is concerned. The most severely eroded land occurs within the Ma nzini, Jabuleni, Lobamba and Chibidze land systems. The universal soil loss equation (USLE) and the soil loss estimator for southern Africa (SLEMSA) give vastly different estimates of the rate of soil loss but no information is available to validate or refute the predictions. (C) 1997 Elsevier Science B.V.