模拟降雨下不同坡度土壤坡面产流产沙特征及磷和钾素流失研究  

Research on Slope Runoff,Sediment and P and K Loss Characteristics on Slopes with Different Gradients Under Artificial Simulation of Rainfall

作　　者：陈诚[1] 郝治邦 

机构地区：[1]黄河水利职业技术学院,河南开封475003 [2]河北省子牙河河务管理处,河北衡水053000

出　　处：《水土保持研究》2017年第2期70-76,83,共8页Research of Soil and Water Conservation

基　　金：国家自然科学基金-河南省人才培养联合基金项目(U1304503);河南省高等学校青年骨干教师资助计划资助项目(2011GGJS-188)

摘　　要：采用室内模拟降雨研究了不同坡度对土壤坡面产流产沙特征及其养分流失的影响。结果表明:在降雨条件下,初始产流时间随坡度的增加而趋于提前,初始产流时间变化范围为0.63~1.62min,说明坡面产流时间因坡面坡度的增加而缩短。不同坡度条件下径流强度随降雨历时的增加而增加,在降雨历时前20min,径流强度急剧增加,降雨历时20min以后,径流强度增加趋势趋于平稳,径流强度遵循幂函数变化规律;不同坡度条件下入渗强度随降雨历时的增加而降低,在降雨历时前20min,入渗强度急剧降低,降雨历时20min以后,入渗强度降低趋势趋于平稳,坡面入渗强度随时间则呈对数函数变化。不同坡度下径流量均随降雨历时呈"增加—稳定"趋势(单峰曲线,抛物线规律),在整个降雨过程中,径流量随坡度的增加而增加,在0~20min内,径流量随降雨历时的增加陡然上升趋势,20~40min,不同坡度条件下土壤泥沙侵蚀量均达到最大值,40min以后泥沙侵蚀量随降雨历时的增加呈现基本平稳趋势,泥沙侵蚀量中DP,K+,SEP和SEK均随着坡度的增加而增加。不同坡度条件下,泥沙量与侵蚀泥沙中养分的含量均存在不同程度的正相关关系,其中坡面坡度为20°,25°和30°时,侵蚀泥沙养分含量与泥沙流失量间的相关性明显优于其他坡度,说明侵蚀泥沙量的增加会引起泥沙中各种类养分含量的增加效应,而随着坡度的增加,侵蚀泥沙量与侵蚀泥沙中养分的含量并非均显示出更进一步的相关性。Simulated rainfall experiments were conducted to investigate the effect of slope gradients on characteristics of runoff,sediment and nutrient losses.The results showed that the runoff occurring times shortened with the increase of slope gradients,and the initial runoff time ranged from 0.63 minute to 1.62 minutes,which indicated that the runoff time shortened with the increase of slope gradients.For the different slope gradients,the runoff intensity increased with the increase of rainfall time,which tended to be stable after 20 minute rainfall and followed the power function,while the average infiltration rate decreased with the increase of rainfall time,which tended to be stable after 20 minute rainfall and followed the logarithmic function.Sediment yields on slope increased with the increase of slope gradients,in 0~20minutes,the sediment yields on the slope increased with the increase of rainfall time,which were the highest during 20~40minutes,and tended to be stable after 40 minutes.The contents of DP,K＋,SEP and SEK increased with the increase of rainfall time.There were the varying degrees of positive correlation between sediment yields and nutrient contents on the slope,and the correlation coefficients in the slope gradients of 20°,25°and 30°were much higher than those in the slope gradients of 5°,10°and 15°,which implied that sediment yield on the slope could cause the increase of various kinds of nutrients,while sediment yields and nutrient contents on the slope had no furthercorrelation with the increase of slope gradient.

关 键 词：模拟降雨 土壤坡度 产流产沙 养分流失 

分 类 号：S157.1[农业科学—土壤学] X14[农业科学—农业基础科学]