Runoff Characteristic of Slope Cropland in the Hilly Area of Purple Soil

Field runoff plots and simulated rainfall experiments were performed to monitor runoff characteristics,process and influencing factors in slope cropland of purple soil.Results showed that:(1) Surface runoff process had some peaks,which could be influenced by rain intensity.However,subsurface runoff process had only peak.Its duration was longer than surface runoff and runoff generated time was lag behind surface runoff.(2) Runoff flux was higher from maturity stage to harvest stage than others stages,when surface and subsurface runoff fluxes were(65.06±5.94) mm and(86.36±3.27) mm accounted for 67.92%,79.82% of total runoff flux.(3) Correlation between surface,subsurface runoff and rainfall was significant,but they were not significantly correlative with rain intensity.Surface runoff coefficient increased with slope adding,but subsurface runoff coefficient decreased with slope adding.(4) Annual surface runoff flux was 95.78 mm,and annual subsurface runoff flux was 108.19 mm,which accounted for 46.96%,53.05% of total runoff flux.