入渗模型对垂直线源灌线源长度的适用性

Applicability of infiltration models to line source length under vertical line source irrigation

为了分析垂直线源灌下土壤水分的入渗规律,探明不同线源长度的入渗率和累积入渗量,通过室内土箱模拟试验,研究了3种常规入渗模型对垂直线源灌下不同线源长度入渗规律的适用性.结果表明,随着线源长度的增加,入渗率和累积入渗量均增大;3种模型均能模拟不同线源长度下的入渗规律,其中Kostiakov入渗公式最精确,Philip入渗模型更适合于入渗前期和中期的模拟,Horton(变形)入渗公式更适合于入渗中期和后期的模拟,并且更适合于线源长度大于20 cm的情况;得出不同线源长度下3种入渗模型的经验公式,3种入渗模型入渗率的经验公式精确度均高于累积入渗量的精确度,3种入渗模型累积入渗量的计算值均高于实测值.该研究结果可为垂直线源灌技术的推广应用提供理论依据.

The law of soil moisture infiltration under vertical line source irrigation was analyzed to investigate the infiltration rate and cumulative infiltration volume of different line source lengths,through the indoor soil box simulation test,three conventional infiltration models for the applicability of the infiltration law of different line source lengths were studied.The results show that the infiltration rate and cumulative infiltration volume increase with the length of the line source,all three models can simulate the infiltration law under different line source lengths,where the Kostiakov infiltration formula is the most accurate,the Philip infiltration model is more suitable for the simulation of the early and middle infiltration,and Horton(deformation)infiltration formula is more suitable for the simulation of the middle and late infiltration.It is more suitable for the case where the length of the line source is greater than 20 cm.The empirical formulas of the three infiltration models under different line source lengths are obtained,the infiltration rate of the three infiltration models is higher than that of the cumulative infiltration volume,and the calculated value of cumulative infiltration amount of three infiltration models is higher than the measured value.The research results can provide a theoretical basis for the popularization and application of vertical line source irrigation technology.