摘要
"上细下粗"的层状土壤中有可能产生指流,在有指流产生条件下,上层土壤的厚度是影响指流发展特征的主要因素之一。该试验通过在下层砂中模拟指流来研究上层土壤厚度对层状土壤中水分运动的影响。结果表明:指流域内的湿润锋到达一定深度的时间随着上层土壤厚度的增大而增加;稳定入渗率随着上层土壤厚度的增大而减小;并得出稳渗率和上层土的厚度呈线性关系;分别用经验函数模型和连续函数模型来模拟层状结构土壤水分的入渗,发现2种模型有各自的优缺点:经验函数模型虽然计算得到的整体误差较小,但在理论上不能很好的解释层状土壤水分入渗过程;连续函数模型相比较经验函数模型的缺点在试验初期误差较大,但该模型属于连续函数模型,符合实际的层状水分入渗过程。
Finger flow can be produced in the layered soil which the structure is the ＂soil top and sand bottom＂.In the condition of finger flow happens,the thickness of upper soils is one of the main factors to influence the development of finger flow.The experiment to simulate the finger flow in the sand layer of the bottom was conducted to research the influence of thickness of upper soils on the layered soil moisture movement.The results indicated that the period that the wetting front of finger flow region arrived in a certain depth increased with the increase of the thickness of upper soils.The stable infiltration rate decreased with the increase of the thickness of upper soils.And stable infiltration rate had linear relationship with the thickness of upper soils.Besides,the experience function model and the continuous function model used to simulate the moisture infiltration of the layer structure soil showed different strengths and weaknesses.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2011年第10期169-173,共5页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金资助项目(50779055)
关键词
土壤
入渗
模型
模拟指流
soils
infiltration
models
simulation finger flow
