非饱和土壤水动力弥散系数的研究  

Study on Coefficient of Unsaturated Soil Hydrodynamic Dispersion

作　　者：李炎[1] 王丹[2] 

机构地区：[1]天津农学院水利工程学院,天津300384 [2]天津农学院园艺园林学院,天津300384

出　　处：《湖北农业科学》2015年第12期2887-2890,共4页Hubei Agricultural Sciences

基　　金：天津农学院科学研究发展基金计划项目(2012N06)

摘　　要：以棕壤土为对象,采用水平土柱入渗法对水动力弥散系数Dsh(θ)进行了分析。试验分2组进行,分别采用初始浓度为0.1%和1%的钾肥(K2SO4)和氮肥(尿素)两种溶液,测定了试验土柱不同刻度处土壤体积含水量θ、土壤溶质浓度C。采用电导率仪和火焰分光光度仪分别测定了土壤溶液的含盐量和水溶性K+浓度。结果表明,Dsh(θ)值与采用何种浓度表示形式无关;不同初始浓度时,同一溶质的水动力弥散系数随浓度的增大而减小;相同初始浓度条件下,尿素溶液的Dsh(θ)小于K2SO4溶液的相应值;非饱和土壤水动力弥散系数Dsh(θ)与扩散系数D(θ)呈现相同的变化趋势。The horizontal infiltration method was used t o measure the coefficient of hydrodynamic dispersion [Dsh（θ）] of brown soil. Two sets of experiments were conducted with concentrations of 0.1% and 1%, respectively. The solute used were potash fertilizer（K2SO4） and nitrogenous fertilizer [CO（NH2）2]. The volumetric water content θ and soil solute concentration C at different place were measured. Two expressions of solute concentration, the salt content and the ion content were measured by using conductivity gauge and flame atomic absorption spectrometer. The results showed that Dsh（θ） was not related to the concentration expression way. For different initial concentration, the Dsh（θ） decreased with the increasing of the solute concentration. With the same initial concentration, the Dsh（θ） of CO（NH2）2was smaller than that of K2SO4. Besides, the variation tendency of Dsh（θ） was the same as the Dsh（θ）.

关 键 词：水动力弥散系数 非饱和土壤 溶质运移 水平土柱入渗法 

分 类 号：S152.7[农业科学—土壤学]