摘要
假定入渗过程分为前期、后期两个阶段,入渗前期土壤饱和区与非饱和区厚度之比为一常数2β,非饱和区厚度随着入渗的进行而逐渐增大;入渗后期非饱和区的厚度不再随时间变化,为一定值,只有饱和区厚度随时间变化,基于此对Green-Ampt模型进行了改进。用传统Green-Ampt模型和改进模型对6组入渗测试资料进行拟合,传统模型拟合的相关系数为0.982(6组数据的平均值),相比传统模型,改进模型的拟合精度明显提高,相关系数提高了0.016,达到0.998(对应β=15);其中两组数据的效果尤为明显,相关系数分别提高了0.07和0.04,均达到了0.99以上。改进模型与传统模型同样具有较强的物理意义,但与传统模型相比,改进模型拟合得到的稳定入渗率更接近于测试值,具有更广泛的适用性。
It is assumed that the infiltration process is divided into two stages of pre-infiltration and post-infiltration. The ratio ofsoil saturated zone to unsaturated zone is a constant 2β in the pre-infiltration stage, and the thickness of unsaturated zoneincreases with infiltration. The thickness of unsaturated zone in the post-infiltration stage no longer changes with time, which is afixed value,and only the thickness of saturated zone changes with time. Based on this, Green-Ampt model is improved. Thetraditional Green-Ampt model and improved model were used to fit six groups of infiltration test data. The correlation coefficientof traditional model fitting was 0.982（the average of six groups of data）. Compared with the traditional model, the fittingaccuracy of the improved model was obvious. The correlation coefficient was increased by 0.016, reaching 0.998（corresponding to β=15） . The data of two groups were especially effective, which were increased by 0.07 and 0.04 respectively,both reaching over 0.99. The improved model has the same strong physical meaning as the traditional model. However, comparedwith the traditional model, the stable infiltration rate obtained by the improved model is closer to the test value and the improvedmodel has wider applicability.
作者
李泳霖
王仰仁
孙小平
郑志伟
LI Yong-lin;WANG Yang-ren;SUN Xiao-ping;ZHENG Zhi-wei(College of Water Conservancy Engineering,Tianjin Agricultural University,Tianjin 300384,China;University-EnterpriseCollaborative Innovation Laboratory ofWater-Saving Irrigation Technology and Equipment,Tianjin 300384,China;Shanxi Institute of Water Resources and Hydropower Research,Taiyuan 030012,China)
出处
《天津农学院学报》
CAS
2018年第3期78-83,共6页
Journal of Tianjin Agricultural University
基金
国家自然科学基金项目(51779174)
天津市农业科技成果转化与推广项目(201701150)
天津市科技计划项目(17YFZC SF00930)
山西省水利科学技术研究与推广项目(201618)
关键词
GREEN-AMPT入渗模型
累计入渗量
非饱和区
入渗锋
入渗时间
Green-Ampt infiltration model
accumulated infiltration capacity
unsaturated zone
infiltration front
infiltration time
