Gully erosion processes: monitoring and modelling

摘要

Soil erosion on hillslopes has been divided traditionally into sheet, rill, and gully erosion. In sheet erosion, a relatively shallow overland fl ow acts on a hillslope and removes sediment particles uniformly from the land surface. The erosion processes can be very gradual and result in an imperceptible change in the landscape during individual storm events. In rill and gully erosion, overland fl ow is concentrated, which markedly increases the erosivity of the fl ow and causes signifi cant incision into the landscape during individual storms. Usually,the relatively smaller rills occur on sloping surfaces, whereas the relatively larger gullies occur within topographic swales or hollows. There remains much discussion on discriminating rill erosion from gully erosion, yet the impact of gully erosion on soil losses deserves special attention.