ARS | Publication request: DETERMINATION OF SPATIAL AND TEMPORAL SOIL EROSION PATTERNS USING RARE EARTH ELEMENTS AS TRACERS

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: October 21, 2001
Publication Date: N/A

Technical Abstract: Characterization of soil erosion rates and patterns within watershed is important for understanding of erosion processes and landscape transformations. Experimental data, which shows spatial translocation of soil on slope, is limited. A method, in which rare earth element (REE) oxides were employed to trace sediment movement within watershed, is under development. In our experiment five REE oxides were uniformly mixed with the soil on different parts of slope in four by four meter soil bed. It allowed monitoring of the process of particle translocation during a series of artificial rainfalls. A laser scanner was utilized to obtain digital elevation maps (DEM) of the soil surface, which were used as reference. REE concentration in on-site and runoff soil samples was determined by inductively coupled plasma mass-spectrometry. Erosion rates for different slope positions predicted from REE concentration in runoff correlated well with those calculated from DEM with relative errors of less than 20 percent. The amount of sediment produced on different parts of the slope varied with the largest erosion occurred at upper middle part of the slope. Our experiment has shown that multi-element tracer method provides a satisfactory way to study soil erosion distribution on uniform slope.