Soil erosion has been divided traditionally into sheet, rill, and gully erosion. In rills and gullies, overland flow is concentrated, which markedly increases the erosivity of the flow, and can cause then significant incisions into the landscape. Usually rills occur on sloping surfaces, whereas gullies occur within swales or hollows. Concentrated flow erosion represents an important -if not the dominant- sediment source within watersheds, producing sizeable economic losses. It is also an important process for transient landscape evolution. These channels are effective links for transferring runoff, sediment and other materials thereby increasing landscape connectivity. The complex physical mechanisms involved in concentrated flow erosion still require more research for a better understanding, with the ultimate aim of developing prediction technology and effective management strategies.
The session pretends to address mainly the following topics: monitoring and measurement techniques; controlling factors; processes; modelling; restoration and control; role of rills and gullies in hydrological and sediment connectivity.