容重对黏壤土土壤水分特征曲线的影响  

Impact of Bulk Density on Soil Water Characteristic Curve of Clay Loam

作　　者：洪成[1] 尹殿胜 陈俊英[2,3] 柴红阳[2,3] HONG Cheng;YIN Dian-sheng;CHEN Jun-ying;CHAI Hong-yang(China Water Huaihe Planning,Design and Researeh Co.,Ltd.,Hefei 230601,Anhui Province,China;College of Water Resources and Architectural Engineering,Northwest A ＆ F University,Yangling 712100,Shaanxi Province;Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A ＆ F University,Yangling 712100,Shaanxi Province,China)

机构地区：[1]中水淮河规划设计研究有限公司,合肥230601 [2]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [3]西北农林科技大学旱区农业水土工程教育部重点实验室,陕西杨凌712100

出　　处：《节水灌溉》2018年第10期5-8,共4页Water Saving Irrigation

基　　金：国家自然科学基金项目(51409221;51349001)

摘　　要：土壤的容重影响土壤孔隙比,从而影响土壤的渗透特性,为研究容重对黏壤土土壤水分特征曲线的影响,选用淮河王家坝附近4个不同容重的黏壤土,采用压力膜法测定其土壤水分特征曲线,用变水头法测定饱和导水率,应用RETC软件中的van Genuchten模型进行拟合。结果表明:在相同的吸力时,黏壤土含水率随容重增加而增加;饱和导水率与容重呈负线性相关(R2=0.963 5),黏壤土饱和含水率θs、残余含水率θr和参数a值与容重呈显著负相关;田间持水率和有效含水率也随容重增加而增加;不同容重的黏壤土非饱和导水率随含水率而增加,在含水率小于0.4 cm^3/cm^3以内,非饱和导水率曲线呈平直状,说明非饱和导水率变化不大,此时的非饱和导水率非常小。当含水率大于0.4 cm^3/cm^3时,非饱和导水率曲线呈陡直状,非饱和导水率变化很大,非饱和导水率相同时,含水率随容重的增加而减小。研究成果可为黏壤土入渗及蒸发数值计算提供支持。The bulk density of soil affects the soil void ratio, thus affects the soil infiltration characteristics. With the aim to explore the effect of bulk density on soil water characteristic curve of clay loam, four soils with different bulk density in HuaiHe fiver were selected. The soil water characteristic curve was determined by pressure membrane. The saturated hydraulic conductivity was determined by the variable head method. The soil-water characteristic curves were fitted by using van Genuchten modelin RETC software. The results show that the water moisture of clay loam increases with the increase of bulk density under the same suction. There is a negative linear correlation （ R2 = 0.963 5 ） between the saturated hydraulic conductivity and the bulk density of the clay loam. The saturated water content 0~, residual water content 0r and parameter a of the clay loam are negatively correlated with bulk density. Field water capacity and effective moisture content also increase with the increase of bulk density. The unsaturated hydraulic conductivities of clay loam with different bulk density increase with the increase of soil moisture. The unsaturated hydraulic conductivity curve is flat when the soil moisture is less than 0.4 cm3/cm3 , indicating that the unsaturated hydraulic conductivity does not change much and the unsaturated hydraulic conductivity at this time is very small. When the soil moisture is more than 0.4 cm3/cm3, the unsaturated hydraulic conductivity curve is steep and straight, and the unsaturated hydraulic conductivity changes greatly. When the unsaturated hydraulic conductivity is the same, the moisture content decreases with the increase of the weight. The conclusions of this research can provide numerical support for clay loam infihration and evaporation.

关 键 词：容重 黏壤土 水分特征曲线 渗透系数 含水率 比水容重 

分 类 号：TV213[水利工程—水文学及水资源]