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.