| ABSTRACT | 第8-9页 |
| ACKNOWLEDGEMENTS | 第10-18页 |
| 1. INTRODUCTION | 第18-22页 |
| 1.1 Research motivation | 第18-22页 |
| 2. REVIEW OF LITERATURE | 第22-34页 |
| 2.1. The mechanism of erosion due to rainfall | 第22-25页 |
| 2.1.1. Detachment of soil | 第23-24页 |
| 2.1.2. Entrainment of Sediment | 第24-25页 |
| 2.1.3. Deposition | 第25页 |
| 2.2. Factors affecting soil erosion | 第25-27页 |
| 2.3. Infiltration and runoff | 第27-28页 |
| 2.3.1. Effect of rainfall | 第27页 |
| 2.3.2. Effect of Slope | 第27-28页 |
| 2.4 Erosions effects | 第28-31页 |
| 2.4.1. Effect on soil erosion on land degradation | 第28-29页 |
| 2.4.2. Effect of soil erosion on soil properties | 第29-30页 |
| 2.4.3. Offsite impacts | 第30-31页 |
| 2.5. Selected management options for controlling soil erosion | 第31-34页 |
| 3. METHODOLOGY | 第34-43页 |
| 3.1. Experimental location and setup | 第34-35页 |
| 3.2. Experimental treatments and measurements | 第35-37页 |
| 3.3. Soil analysis | 第37-43页 |
| 3.3.1. Sample preparation | 第37页 |
| 3.3.2. Total nitrogen | 第37-38页 |
| 3.3.3. Total Phosphorus and Potassium | 第38-39页 |
| 3.3.4 Soil organic carbon | 第39-40页 |
| 3.3.5. Available Nitrogen | 第40页 |
| 3.3.6. Available Phosphorus | 第40-41页 |
| 3.3.7. Particle Size determination | 第41页 |
| 3.3.8. Calculations and statistical analysis | 第41-43页 |
| 4. RESULTS | 第43-101页 |
| 4.1 Temporal variations in runoff losses under different slopes and rainfall intensitiesin unmulched soil | 第43-45页 |
| 4.2 Runoff losses under different slopes and rainfall intensities in unmulched and mulched soil | 第45-51页 |
| 4.2.1. Slope and Rainfall contributions for runoff losses under different slopes and rainfallintensities in unmulched and mulched soil | 第49-51页 |
| 4.3 Water conservation effectiveness of mulch under different slopes and rainfall intensities | 第51-54页 |
| 4.4 Temporal variations in sediment losses under different slopes and rainfall intensitiesin unmulched soils | 第54页 |
| 4.5. Sediment losses under different slopes and rainfall intensities in unmulched andmulched soil | 第54-60页 |
| 4.5.1. Slope and rainfall contributions for sediment losses in unmulched and mulched soil | 第59-60页 |
| 4.6. Soil conservation effectiveness of mulch under different slopes and rainfall intensities | 第60-62页 |
| 4.7. Water infiltration under different slopes and rainfall intensities in unmulched and mulched soil | 第62-66页 |
| 4.8. Water recharge coefficient under different slopes and rainfall intensities in unmulched andmulched soil | 第66-69页 |
| 4.9. Clay (0-2μm) contents(%)in surface soil under different slopes and rainfall intensities inunmulched and mulched soil | 第69-71页 |
| 4.10. Fine silt (2-20μm) contents(%)in surface soil under different slopes and rainfall intensitiesin unmulched and mulched soil | 第71-73页 |
| 4.11. Coarse silt (20-5μm) contents(%)in surface soil under different slopes and rainfallintensities in unmulched and mulched soil | 第73-74页 |
| 4.12. Sand (>50μm) contents(%)in surface soil under different slopes in surface soil and rainfallintensities in unmulched and mulched soil | 第74-77页 |
| 4.13. Relative changes in particle size distributions of surface soils compared with pre-simulatedsoil | 第77-79页 |
| 4.14. SOC contents (g/kg) in surface soil under different slopes and rainfall intensities inunmulched and mulched soil | 第79-80页 |
| 4.15. Reductions(%)in SOC contents of top surface soil compared with pre-simulatedsoil | 第80-82页 |
| 4.16. Total N contents (g/kg) in surface soil under different slopes and rainfall intensities inunmulched and mulched soil | 第82-84页 |
| 4.17. Reductions(%)in total N in contents of top surface soil compared with pre-simulatedsoil | 第84-85页 |
| 4.18. Available N contents (mg/kg) in surface soil under different slopes and rainfallintensities in unmulched and mulched soil | 第85-86页 |
| 4.19. Reductions(%)in available N contents of top surface soil compared pre-simulated soil | 第86-88页 |
| 4.20. Total P contents (g/kg) in surface soil under different slopes and rainfall intensities inunmulched and mulched soil | 第88-90页 |
| 4.21. Reductions(%)in available N contents of top surface soil compared with pre-simulatedsoil | 第90-91页 |
| 4.22. Available P contents (mg/kg) in surface soil under different slopes and rainfall intensities inunmulched and mulched soil | 第91-92页 |
| 4.23. Reductions(%)in total P contents of top surface soil compared with pre-simulated | 第92-93页 |
| 4.24. Total K contents (mg/kg) in surface soil under different slopes and rainfall intensities inunmulched and mulched soil | 第93-95页 |
| 4.25. Nutrients conservation by mulch under different rainfall intensities | 第95-96页 |
| 4.26. Nutrients conservation by mulch under different slopes | 第96-100页 |
| 4.27. Correlations between different variables | 第100-101页 |
| 5. DISCUSSION | 第101-116页 |
| 5.1. Surface runoff | 第101-103页 |
| 5.2. Sediment losses | 第103-105页 |
| 5.3. Water Infiltration | 第105-107页 |
| 5.4. Recharge coefficient | 第107-108页 |
| 5.5. Particle size distribution | 第108-111页 |
| 5.6. SOC in surface soil | 第111-113页 |
| 5.7. Total Nitrogen and available N in surface soil | 第113-114页 |
| 5.8. Total P and available P in surface soil | 第114-115页 |
| 5.9. Total K in surface soil | 第115-116页 |
| 6. CONCLUSIONS | 第116-119页 |
| 7. REFERENCES | 第119-139页 |
