Soil erosion in the Herschel district of South Africa: changes over time, physical correlates and land users' perceptions
AbstractSoil erosion in rangelands is widely believed to be caused primarily by overgrazing. The aims of this study, conducted in a severely eroded district under communal tenure, were to establish (1) how the extent and severity of soil erosion have changed over time, (2) how soil erosion varies within the district and what variables correlate with high levels of soil erosion, and (3) how the perceptions of the local people reflect the realities of degradation. Analyses of aerial photographs showed that the extent and severity of erosion increased substantially since 1950, with the area affected by erosion doubling in some areas between 1950 and 1969. Soils derived from alluvium and sedimentary rocks were more eroded than soils derived from basalt and dolerite. Flat or gently sloping areas were most severely affected by erosion. The fact that most of these areas had been ploughed and since abandoned and used for grazing livestock supports people's perception that the abandonment of cultivated land was a major factor leading to increases in severe forms of soil erosion. This suggests that interventions to prevent severe forms of soil erosion should focus on preventing ploughing of marginal land and protecting abandoned lands from grazing.
Keywords: aerial photographs, communal lands, gully erosion, land abandonment
African Journal of Range & Forage Science 2007, 24(2): 77–86