Abstract:In this paper, the artificial simulated rainfall combined with the indoor backfill soil trough was used to study the difference among the characteristics of the runoff and sediment yield in the red soil slopes with different parent meterials: granite, quaternary and red sandstone. Results showed that the order of surface runoff time of the three parent materials was granite<red sandstone<quaternary, averaging runoff rates and the total amount of runoff were granite>red sandstone>quaternary, where the runoff amount of granite red soil under 45 mm/h rainfall was 1.79~2.47 times of those of red sandstone and quaternary, and the averaging runoff rate was 1.58~2.32 times of those of the latter two. Under the rainfall conditions of 45 mm/h, the sediment concentration of the field was the quaternary>granite>red sandstone, while, it was granite>red sandstone>quaternar under 135 mm/h. The rain intensity had a greater influence on the sediment yield of red soil slope, and the sediment concentration under 135 mm/h was 8.31~11.32 times of 45 mm/h. As for the runoff composition, the proportion of interflow in runoff was highest in quaternary red soil among the materials, which was about 8%~44% in the two rain intensities. The larger rain intensity, the more obvious effect of the surface confluence, which could reach up to 79%~90% of the total runoff under 135 mm/h. The runoff time of interflow was same as that of the surface runoff: granite<red sandstone<quaternary, the interflow of granite red soil was smallest, accounting for only 53%~67% of the quaternary, and even 42%~52% at the peak runoff. After the rainfall, the regression of interflow could be predicted by an exponential function, all the decision coefficients were above 0.82 for all conditions, showing a good predictability.