盐溶液对土壤入渗特性的影响

目的]分析盐溶液对土壤入渗特性的影响,为进一步研究供水水质对土壤入渗特性影响及机理提供参考。方法]以NaCl、CaCl2溶液为主要试验材料,利用室内一维垂直土柱积水入渗试验,研究不同种类、不同浓度的盐溶液对土壤入渗能力的影响。结果]溶液浓度对水分入渗性能有一定影响,2种溶液入渗率、累积入渗量及湿润锋推进距离的变化表现为50 mg/L>100 mg/L>10 mg/L;溶液浓度相同情况下,不同溶液对水分入渗的影响表现为:NaCl溶液对土壤入渗特性的影响比CaCl2溶液显著,相同时间内,NaCl溶液的累积入渗量和湿润锋推进距离均大于CaCl2溶液;CaCl2溶液相较于NaCl溶液,入渗相同水量所需要的时间长,入渗率较小。入渗率、累积入渗量和湿润锋动态变化符合Philip入渗模型。结论]该研究仅对室内土柱盐溶液入渗情况进行了分析探讨,涉及浓度较低、范围较小,虽在一定程度上为研究供水水质对土壤入渗特性影响及机理提供了参考,但仍需进行更大空间和更大浓度范围的试验研究和探讨工作。

Effect of Salt Solution on Characteristics of Soil Infiltration

Objective]The aim was to study the effect of salt solution on characteristics of soil infiltration,and to provide references for the further studies on the effect of water quality on soil infiltration characteristics and its mechanism.Method]With the NaCl,CaCl2 solutions as the main test materials,the effect of different water quality and salt solution concentration on soil infiltration was studied under one-dimensional vertical ponded water infiltration at laboratory.Result]The solution concentration could affect the infiltration performance.The trends of the infiltration rates,cumulative infiltrations and wetting front migration distances were all 50 mg/L > 100 mg/L > 10 mg/L.At the same concentration,the effect of NaCl solution on soil infiltration characteristics was more significant than CaCl2 solution: in the same time,cumulative infiltration and wetting front migration distance of NaCl solution were greater than CaCl2 solution;compared with NaCl solution,CaCl2 solution took longer time to infiltrate the same amount of water.The dynamic changes of infiltration rate,wetting front and cumulative infiltration were well fitted to the Philip model.Conclusion]This study only conducted indoor experiment to the infiltration of salt solutions,involving in low concentration and small range.Although it provided some references for the study of the effect of water quality on soil infiltration characteristics and its mechanism,studies in larger areas and with bigger concentrations are demanding.