电阻法在喷灌土壤水分入渗再分布测定中的应用

Application of Electric Resistance Method for Measuring Soil Water Infiltration and Redistribution under Sprinkler Irrigation

土壤通常是导电的,其电阻率随其含水量的大小而变化,电阻式土壤水分动态测定仪就是基于这种原理进行测量的。通过土壤电阻率的突变可以判断土壤水分湿润锋到达的时间,不同深度的探头组合就可以分析得出土壤水分入渗速率,可以定量研究土壤水分的入渗过程。田间试验结果表明:喷灌土壤水分入渗时间和入渗深度之间的关系可以表示为对数形式。电阻法测定土壤水分入渗还需要进一步研究。

Electric resistance soil water dynamics meter works with the theory that soil is commonly electric and its resistivity changes with its water content. The wetting front arrival time could be judged by the mutation of soil resistivity, and using the different sensors, the soil water infiltration rate could be obtained. Through this method, the soil water infiltration process could be quantiteatively studied. The field experiment results indicated that the relation of soil water infiltration time and infiltration depth could be expressed by the logarithmic equation under sprinkler irrigation. The further study was needed on measuring soil water infiltration by electric resistance method.