ABSTRACT
In his study of soil erosion, Ellison (1947) identified four elements constituent to the process. Two agents, rainfall and surface flow, may each effect the two mechanisms of detachment and transportation. This conceptual framework has underpinned many models of sediment removal in interrill overland flow (e.g. Meyer & Wischmeier 1969, Rowlinson & Martin 1971). Investigations of the roles of the four elements (e.g. Young & Wiersma 1973, Quansah 1985), however, have yielded information on their relative
importance, with the result that many models of interrill erosion now simplify the process to one in which rainfall is responsible for detachment (e.g. Rowlinson & Martin 1971, Foster & Meyer 1972) and surface flow alone is responsible for transportation (e.g. Hartley 1987).
