Factors influencing soil loss
The relationship between sediment yield and splash-detachment, splash-transport, total runoff, and surface flow rate was analyzed, as shown in Figure 8 and Table 4. The mulching treatments could restrict splash-erosion to very low levels, reducing the average splash-detachment and splash-transport amounts from 143.16 to 1.13 g m-2 h-1 and from 1063.90 to 8.93 g m-2 h-1, respectively. The ridge treatments had no significant impacts on splash-erosion. Thus, for uncovered plots, splash erosion was mainly based on rainfall intensity. The linear correlation coefficients (R2) of the splash-detachment and splash-transport rates to rainfall intensity were 0.93 and 0.98, respectively. The splash rates of Cm were also partly related to the rainfall intensity, but the correlation was more complicated, and thus further study is needed.
In general, the total soil loss increased with the splash-erosion rate, escalating in non-mulching treatments under light rainfall conditions. However, when the plots suffered ridge rupture, the impact of splash-erosion on soil loss appeared to be insignificant. With an increase in runoff volume and velocity, soil loss would also normally ascend, and thus treatments with high runoff volume and velocity would also lead to serious soil loss. However, this regulation was not applicable to mulching treatments.