非稳定流条件下非饱和均质土壤溶质运移的传递函数解  

Transfer function approach of solute transport in unsaturated homogeneous soil under unsteady flow condition

作　　者：任理[1] 刘兆光[1] 李保国[1] 

机构地区：[1]中国农业大学土壤和水科学系,北京100094

出　　处：《水利学报》2000年第2期7-15,共9页Journal of Hydraulic Engineering

基　　金：国家重点基础研究发展规划项目!(G1999011803);"九.五"国家重点科技攻关项目!(9600401142)

摘　　要：根据溶质运移的传递函数模型Ｔｒｏｍｓｆｅｒ Ｆｕｎｃｔｉｏｎ Ｍｏｄｅｌ，ＴＦＭ 理论， 研究了非稳定流条件下非饱和均质土壤中表施和原有ＮＯ－３ Ｎ 及原有Ｃｌ－ 的运移． 由极大似然法估算了模型参数μ和σ２ ， 求出了溶质运移的概率密度函数， 计算了ＮＯ－３ Ｎ 的淋失量， 并利用土壤中原有Ｃｌ－ 的动态， 对ＮＯ－３ Ｎ 的迁移过程进行了模拟， 同时还估算了溶质的中值迁移时间ｔｍ 和均值迁移时间珋ｔ 及相应的运移体积θ′ｓｔ和θ″ｓｔ．Based on the theory of transfer function model,the transport of surface\|applied and indigenous nitrate and chloride in unsaturated homogeneous soil under unsteady condition is investigated experimentally.The mean and variance of log\|normal distribution probability density function(pdf) of the travel time are evalutated by the maximum likelihood method,and then the quantity of leached nitrate\|nitrogen is determined accordingly.The process of nitrogen leaching is predicted using the transport of the indigenous chloride in soil.The median travel time and mean travel time as well as the transport volume are also estimated.

关 键 词：溶质运移 传递函数模型 非稳定流 非饱和土壤 

分 类 号：S153.5[农业科学—土壤学] TV121.3[农业科学—农业基础科学]