A study on sediment sources in a small watershed by using REE tracer method

In simulation experiments, rare earth element (REE) tracer method was first used to study the sources of sediment yield in a small watershed. The experimental results have shown that the chief parts of sediment sources are constantly changing with the development of gullies. The cutting erosion plays a major role in the primary stage of watershed development. Slope erosion intensity increased gradually with gully development of the watershed, while gully erosion intensity decreased. Similar process was also observed in an individual rainfall. The simulation experiments have shown that the method can satisfactorily interpret the origins of sediment yield of a small watershed in an effective way. The simulation experiments have also provided basic information for field researches.