砾石覆盖厚度对斥水土壤入渗特性的影响及模型优选  

Effect of Thickness of Gravel Cover on Infiltration Characteristics of Water Repellent Soils and Its Model Optimization

作　　者：胡廷飞 王辉[1] 胡传旺[1] 何杏杰 刘华涛 HU Tingfei;WANG Hui;HU Chuanwang;HE Xinjie;LIU Huatao(Department of Engineering,Hunan Agricultural University,Changsha 410128)

机构地区：[1]湖南农业大学工学院,长沙410128

出　　处：《水土保持学报》2019年第2期17-22,29,共7页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41471185);湖南省教育厅重点项目(15A084);湖南省重点研发计划项目(2016JC2032)

摘　　要：基于室内一维垂直入渗土柱试验,研究砾石覆盖厚度(0,3,6,9,12 cm)对斥水土壤积水入渗及水分再分布的影响,并利用不同入渗模型进行拟合。结果表明:砾石覆盖显著增加斥水土壤湿润锋运移距离(p<0.05);同一时段内,各处理累积入渗量皆高于对照组(p<0.05),斥水性红壤累积入渗量与砾石覆盖厚度呈正相关关系;斥水性红壤初渗率与稳渗率随砾石覆盖厚度变化均可用指数函数来描述,决定系数分别为0.91和0.87,砾石覆盖使得斥水性潮土初渗率与稳渗率增大,其中稳渗率与砾石覆盖厚度呈二次函数关系,决定系数为0.78,覆盖6 cm时稳渗率达到最大;砾石覆盖明显提高斥水土壤剖面平均含水率,斥水性红壤和潮土最大分别增长180.8%和57.6%;隔绝蒸发条件下,再分布过程斥水土壤湿润体含水率表现为停渗时刻>再分布1天>再分布3天>再分布7天;Horton模型对砾石覆盖斥水土壤入渗过程的拟合效果最好,是分析和预测砾石覆盖斥水土壤水分入渗特征的适宜模型。Based on one-dimensional vertical infiltration experiments,we studied the effects of thickness of gravel (0,3,6,9,12 cm) on water infiltration and redistribution in water repellent soils with constant bulk density,and the infiltration process were simulated using different models.The results showed that the migration distance of the wetting fronts were increased significantly (p <0.05).Within the same period,all the cumulative infiltrations,which were positively correlated with the thickness of gravel,were higher under gravel covered treatments than that of the control group (p <0.05) in water repellent red soil.Both the stable infiltration rate and initial infiltration rate of the water repellent red soil could be described by exponential function with the thickness of gravel cover,and the coefficients of determination were 0.91 and 0.87 respectively.Compared with the control group,the gravel cover increased the stable infiltration rate and initial infiltration rate of water repellent tidal soil,the stable infiltration rate had a quadratic relationship with the thickness of gravel,the coefficient of determination was 0.78.The stable infiltration rate reached the maximum when the thickness of gravel was 6 cm.The water content in the section of water repellent soils was increased,with the largest increases of 180.8% and 57.6% respectively in red soil and tidal soil.Under the condition of isolated evaporation,the water contents of the upper layer in the water repellent soil under different thicknesses of gravel cover (above the wetting front) showed: stop infiltration>redistributed for 1 day>redistributed for 3 days>redistributed for 7 days.Horton infiltration model had the best fitting effect on water repellent soil infiltration under gravel cover,which made it suitable to analyze and predict the infiltration process in water repellent soils under gravel cover.

关 键 词：斥水土壤 砾石厚度 入渗 水分再分布 入渗模型 

分 类 号：S152.72[农业科学—土壤学]