Significance and contribution rate of effects of rainfall intensity and slope gradient on the percentage of different-sized fractions in sediment by sheet erosion based on ANOVA
| Variable . | Source . | DF . | Type III sum of squares . | Mean square . | F . | Sig. . | PC . |
|---|---|---|---|---|---|---|---|
| P<2μm | I | 4 | 86.082 | 21.520 | 13.611 | 0.000 | 23.44% |
| S | 4 | 198.726 | 49.681 | 31.421 | 0.000 | 56.54% | |
| I × S | 16 | 15.944 | 0.996 | 0.630 | 0.830 | / | |
| Error | 25 | 39.529 | 1.581 | ||||
| Total | 49 | 340.280 | |||||
| P2–50μm | I | 4 | 69.143 | 17.286 | 10.483 | 0.000 | 35.45% |
| S | 4 | 49.684 | 12.421 | 7.533 | 0.000 | 24.42% | |
| I × S | 16 | 16.380 | 1.024 | .621 | 0.838 | / | |
| Error | 25 | 41.224 | 1.649 | ||||
| Total | 49 | 176.430 | |||||
| P50–250μm | I | 4 | 128.674 | 32.168 | 27.625 | 0.000 | 29.09% |
| S | 4 | 259.993 | 64.998 | 55.818 | 0.000 | 59.89% | |
| I × S | 16 | 8.548 | .534 | .459 | 0.945 | / | |
| Error | 25 | 29.112 | 1.164 | ||||
| Total | 49 | 426.326 | |||||
| P>250μm | I | 4 | 38.833 | 9.708 | 88.032 | 0.000 | 56.82% |
| S | 4 | 21.704 | 5.426 | 49.201 | 0.000 | 31.47% | |
| I × S | 16 | 4.273 | .267 | 2.422 | 0.023 | 3.71% | |
| Error | 25 | 2.757 | .110 | ||||
| Total | 49 | 67.567 |
| Variable . | Source . | DF . | Type III sum of squares . | Mean square . | F . | Sig. . | PC . |
|---|---|---|---|---|---|---|---|
| P<2μm | I | 4 | 86.082 | 21.520 | 13.611 | 0.000 | 23.44% |
| S | 4 | 198.726 | 49.681 | 31.421 | 0.000 | 56.54% | |
| I × S | 16 | 15.944 | 0.996 | 0.630 | 0.830 | / | |
| Error | 25 | 39.529 | 1.581 | ||||
| Total | 49 | 340.280 | |||||
| P2–50μm | I | 4 | 69.143 | 17.286 | 10.483 | 0.000 | 35.45% |
| S | 4 | 49.684 | 12.421 | 7.533 | 0.000 | 24.42% | |
| I × S | 16 | 16.380 | 1.024 | .621 | 0.838 | / | |
| Error | 25 | 41.224 | 1.649 | ||||
| Total | 49 | 176.430 | |||||
| P50–250μm | I | 4 | 128.674 | 32.168 | 27.625 | 0.000 | 29.09% |
| S | 4 | 259.993 | 64.998 | 55.818 | 0.000 | 59.89% | |
| I × S | 16 | 8.548 | .534 | .459 | 0.945 | / | |
| Error | 25 | 29.112 | 1.164 | ||||
| Total | 49 | 426.326 | |||||
| P>250μm | I | 4 | 38.833 | 9.708 | 88.032 | 0.000 | 56.82% |
| S | 4 | 21.704 | 5.426 | 49.201 | 0.000 | 31.47% | |
| I × S | 16 | 4.273 | .267 | 2.422 | 0.023 | 3.71% | |
| Error | 25 | 2.757 | .110 | ||||
| Total | 49 | 67.567 |
Note: P<2μm, P2–50μm, P50–250μm, and P>250μm are the percentages of the clay-, silt-, fine-sand, and coarse-sand-sized fractions in effective sediment yield by sheet erosion, respectively, I is the rainfall intensity (mm min−1), S is the slope gradient (°), DF is the degree of freedom, and PC is the percentage contribution of each factor (%), calculated by using Equation (12).