Effect of Surface Cover and Slope on Runoff and Soil Erosion

摘要

Agricultural activities on sloping fields cause soil erosion due to incomplete cover of soil surface during rainfall events, agricultural productivity is lowered, and muddy runoff in streams and lakes causes water quality deterioration and eutrophication. In this study, effect of straw cover and slope ofplot(5%, 10%, 20%) and rainfall intensity(30mm/h, 60mm/h) on surface runoff and sediment discharge were discussed. The surface runoff showed increasing tendency in both straw covered and bare boxes asthe slope(5%, 10%, and 20%) increased. Also the surface runoff volume from straw covered surface boxes were much lower than bare surface boxes. Under the same rainfall intensity and slope condition, 2.4- 8.2 times of sediment yield were occurred from bare surface boxes compared to straw covered surface boxes. The volume of infiltrated water increased due to straw cover, the direct runoff decreased with the increase of infiltration and of tractive force in surface.