Rain simulation of dynamic soil erosion processes with rare earth element tracers

A new idea was advanced to identify the initiation and the development of the dynamic soil erosion processes with the rare earth elements(REE) method under simulated rainfall conditions. A series of experiments were conducted with Dy, La, Sm, Yb, Ce, Eu, Nd and Tb under laboratory rainfall simulator conditions at three different rainfall intensity(50, 100 and 150 mm/h) and four slope gradients(8.74%, 17.63%, 36.4% and 46.63%). Two consecutive rainstorms were applied with a 24 hours interval. The initiation and development of soil erosion along slope was studied. And the dynamic equilibrium of runoff and soil erosion along slope was quantitatively analyzed. This paper revealed clearly the occurrence and development processes of soil erosion, and showed the development of the rill and soil erosion along slope. The results show that soil erosion mainly occurs the upper slope with the bigger rain intensity and slope, which is consistent with the gully erosion.