Effect of Different Rainfall Conditions on Runoff and Sediment Process to the Primary Management Measures in Loess Plateau Regions

On the base of artificial rainfall experiments,the results of effect different rainfall conditions on runoff and sediment process to the primary management measures were obtained.The results showed that the initial time of runoff was different to all the management measures under the different rainfall conditions.Under the different rainfall intensity,runoff intensity processes were from the first rising in volatility to declining trends on the slope with rake and slope with hoe.On the condition of rainfall intensity of 1.50 mm/min,the runoff intensity process was from the increasing to declining trends on the slope with dig.However,on the condition of rainfall intensity of 0.68 mm/min,the runoff intensity process was the increasing from the beginning on the slope with dig.On the condition of rainfall intensity of 1.50 mm/min,the runoff intensity process was the increasing from the beginning trends with the volatile on the slope with contour.However,on the condition of rainfall intensity of 0.68 mm/min,the runoff intensity process was from the increasing to declining trends on the slope with contour.Rainfall intensity had greater impact to the cumulative runoff and sediment yield,and cumulative runoff and sediment yield increased with the increasing rainfall intensity on the slope of the various management measures.However,the effects management measures on the dynamic process of the water and sediment were different.The results would provide theory basis for harnessing soil and water loess and reclaiming forest and grass from farmland in loess plateau.