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]