3.4. Contribution of slope gradient and vegetation cover to sediment yielding
The contribution index of vegetation cover and slope to accumulative sediment yield and runoff sediment concentration varied with slope (Fig. 8). On the flattest slope (5°), the sediment yield was almost entirely affected by vegetation cover. On slopes >10°, the contribution of slope gradient on sediment yield ranged from 0.51 to 0.6. From the 10° slope, the sediment yield caused by slope gradient was greater than that of vegetation cover.
[Insert Figure 8]
These results were supported by the two-way ANOVA, which showed that the slope gradient had significant effects on runoff sediment concentration, accumulative sediment yield, and erosion sediment yield (Table 2), whereas vegetation cover had a significant effect only on the accumulative sediment yield and erosion sediment yield. The interaction between slope gradient and vegetation cover was not significant for any of the three ANOVA modes of sediment yield.
[Insert Table 2]