气相阻力与土壤容重对一维垂直入渗影响的定量分析

Quantitative Analysis of Influence of Air Resistance and Soil Bulk Density on One-dimensional Vertical Infiltration

分析了土壤容重和气阻对一维垂直积水入渗的入渗率、累积入渗量以及湿润锋的影响,并对入渗过程中土壤平均含水率增量进行了研究。容重和气阻均对入渗率、累积入渗量和湿润锋有明显的影响:容重增加导致累积入渗量减少的减渗率在入渗过程中为一常数,相对于容重为1.3g/cm3土壤的累积入渗量,容重为1.4g/cm3和1.5g/cm3土壤的减渗率分别为31.79%和52.03%。容重增加导致湿润锋减少的减渗率在入渗过程中并非一常数,受到了入渗时间的影响;气阻导致累积入渗量和湿润锋减少的减渗率随基准入渗量的增加而变大,受到了入渗时间的影响。对应于1.3,1.4,1.5g/cm3等3个容重土壤的积水入渗,入渗过程中土壤剖面平均含水率增量Δθ分别为0.377,0.3411,0.3137。

The influence of air resistance and soil bulk density on infiltration rate, accumulative infiltration and wetting front was analyzed, and the average water content increment during infiltration was researched. Air resistance and soil bulk density have obvious influence on infiltration rate, accumulative infiltration and wetting front： the infiltration decrease ratio（IDR） of accumulative infiltration due to soil bulk density increment was a constant,and IDR was 31.79% and 52.03% for 1.4 g/cm^3 and 1.5 g/cm^3 soil bulk density compare to 1.3 g/cm^3 soil bulk density. The infiltration decrease ratio （IDR） of wetting front due to soil bulk density increment was not a constant which was influenced by time. The infiltration decrease ratio（IDR） of accumulative infiltration and wetting front due to air resistance was not a constant which was influenced by time. The average water content increments during infiltration were 0.377, 0.341 1 and 0.3137 for 1.3,1.4 and 1.5 g/cm^3 soil bulk density, respectively, in condition of no air resistance.