降雨对黄土区主要管理措施坡耕地水沙动态过程的影响

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

通过室内人工模拟降雨的方法,分析了降雨对管理措施坡耕地水沙动态过程的影响。研究结果表明:在降雨条件下,实施管理措施坡耕地初始产流时间有所不同。耙耱地措施和人工锄耕,不同雨强条件下的径流强度过程线从开始产流都呈现出先波动上升、后下降的变化趋势。人工掏挖,在雨强1.50mm/min条件下径流强度过程线从开始产流呈现出先上升、后下降的变化趋势,波动性较大;而雨强0.68mm/min条件下径流强度过程线从开始产流却一直呈增加的变化趋势。等高耕作,在雨强1.50mm/min条件下径流强度过程线从开始产流呈现出一直增加的变化趋势,起始波动性较大;而雨强0.68mm/min条件下径流强度过程线从开始产流却呈先增加、后降低的变化趋势。降雨强度对实施管理措施坡面累积产流产沙过程影响较大,随雨强的增大,累积产流产沙也随之增加,但各管理措施对水沙动态过程影响程度不同。这为揭示人为管理措施的水保效应提供了一定的理论依据,同时也可服务于黄土区坡耕地水土流失的治理。

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.