A STUDY ON THE EFFECT OF SPATIAL SCALE ON THE PARAMETERS OF A SEDIMENT TRANSPORT-EQUATION FOR SHEETWASH

Event-based prediction of soil erosion over large agricultural fields and drainage basins is limited by the lack of data for the relevant sc ales of applications. Thus, researchers have to assume that the parame ters of the sediment transport equation obtained from very small scale can be transferred to large scale systems. This assumption remains un tested. The objectives of this paper are: (1) to illustrate, by a comp ilation of a wide range of experiments on sheetwash erosion, the lack of investigations conducted on an event by event basis over agricultur al fields; (2) to present a synthesis of results obtained during three experiments conducted for short duration events at various spatial sc ales ranging from 0.25 to 55 meters. The results will show the possibi lity of using a relation calibrated for a small scale experimental plo t on a larger scale agricultural field under specific conditions.