Contribution to runoff erosion of earthen channels

The purpose of the experimental study is to investigate the effect of earthen channel geometry on erosion by runoff. After the construction of an experimental setup, four geometric shapes were tested; the circle, the triangle, the sinus and the trapeze. These four forms were dug in agricultural sandy-loam soil. For all experiments, and for each geometric shape, discharge, slope inclination, time, and slope length were varied. Experimental results have shown that the geometry of earthen channels plays an important role in sedimentary dynamics. In addition, it was noted that for slopes less than 20%, the sinusoidal geometric shape allowed to have the minimum of sediment exported. For upper slopes, the minimum amount of soil exported, was obtained with the triangle. The analysis of the experimental results allowed us to see that the variation of the mass of soil exported as a function of the discharge, the slope inclination, the time and the slope length, followed power functions with respective exponents of 2.49, 0.88, -1.27, and -1.53.