The relationship between rainfall, runoff and soil loss from different slope angles of purple soil still remain unclear despite numerous studies. This study was carried out in the laboratory to estimate runoff and sediment yield from different slope angles (5Â°, 10Â°, 15Â°, 20Â° and 25Â°) using Norton rainfall simulator and soil boxes. The soil was subjected to different rainfall intensities 0.6, 1.1, 1.5 and 1.8 mm/min. Results showed runoff rates decreased in 100 > 200 > 150 > 250 > 50 order with values ranged from 0.26 mm/min for low rainfall intensity (0.6 mm/min) on slope 50 to 1.06 mm/min for simulation experiments with higher rainfall intensity (1.8 mm/min) on slope 100. Pearson correlation showed a strong correlation (p<0.001) between rainfall intensity and runoff rate. Soil loss linearly increased with runoff rate and slope angles (from 1255.66 gm-2h-1 under rainfall 1.8 mm/min on slope 250 to 55.97 gm-2h-1 under 0.6 mm/min on slope 50). From RÂ² values, runoff strongly explained for 53 to 81% the variance in sediment detachment. Assessment of rainfall function on purple soil may help to build conservative measures and strategies in controlling soil loss under different rainfall intensities in Sichuan basin. Key words: Purple soil, Rainfall simulation, Rainfall intensity, Runoff, soil erosion.
Keywords: Purple soil, Rainfall simulation, Rainfall intensity, Runoff, soil erosion.