Effect of slope length, aspect and phosphogypsum on runoff and erosion from steep slopes

The efficiency of phosphogypsum as an amendment for controlling erosion on embankments was studied on a Typic Rhodoxeralf soil, with 48% slope and 10 and 1-5 m long plots, with western and northern aspects and a westerly dominant wind during rainstorms. Phosphogypsum reduced the runoff by 23%, and the erosion was 2-3 times less than on the control slope. The embankment’s aspect has no effect on the amounts of rainfall and runoff, but the erosion from the long plots with a western aspect compared with the long plots with a northern aspect was 1-4 and 2-5 times higher in the control and phosphogypsum treatments, respectively. The length of the plots has no effect on the runoff, however, soil loss was 6-4 times higher in the longer plots. High correlations were found between the amount of erosion and the erosivity index or the runoff amount.