不同负压设置对微型盘式入渗仪测定结皮入渗性能的影响  

Effect of Suction in the Infiltrometer on Water Infiltration into Crusted Soils

作　　者：李建德 王健[2] 徐飞飞 王康宏 杨琴侠 薛冬 LI Jiande;WANG Jian;XU Feifei;WANG Kanghong;YANG Qinxia;XUE Dong(Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China;College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,China;Hancheng Soil and Water Conservation Workstation,Hancheng 715400,China)

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]西北农林科技大学资源环境学院,陕西杨凌712100 [3]韩城市水土保持工作站,陕西韩城715400

出　　处：《灌溉排水学报》2022年第7期78-85,共8页Journal of Irrigation and Drainage

基　　金：国家自然科学基金项目(41771308)。

摘　　要：【目的】定量描述负压设置对微型盘式入渗仪测定结皮入渗性能的影响。【方法】通过人工模拟降雨,以黄土坡面土壤物理结皮为研究对象,采用微型盘式入渗仪进行入渗试验,设置5个负压梯度(1~5 cm),量化不同负压设置对入渗指标测定的影响,同时以定水头法得到的饱和导水率为标准,分析比较基于Wooding模型与Philip模型两种计算方法的准确度。【结果】定水头法具有可重复性与准确性,得到结构结皮饱和导水率为74.00 cm/d,沉积结皮饱和导水率为12.00 cm/d;采用微型盘式入渗仪测定两类结皮的土壤累积入渗量、稳渗速率、吸渗率、导水率等指标,测定结果随仪器负压设置增大而减小;微型盘式入渗仪法测算土壤饱和导水率时,基于Philip模型的计算方法更为准确,但结果随负压设置影响较大,以定水头法得到的饱和导水率为参照,率定van Genuchten参数α与n,结构结皮分别为0.039与2.72,沉积结皮分别为0.024与2.83。【结论】采用微型盘式入渗仪进行入渗试验时必须考虑不同负压设置对测定结果的影响和仪器给定参数对土壤饱和导水率计算的适用性,以准确描述土壤入渗特性,为土壤侵蚀预报等提供理论依据。【Objective】Infiltrometer is a device to measure water infiltration into soil and soil hydraulic conductivity.Its performance depends on many factors.This paper aims to study the effect of the negative pressure in it on water infiltration in crusted soil.【Method】The crusts on the soil surface were created by artificial rainfalls on a loess slope;water infiltration into the soil was measured using a mini disc infiltrometer with the negative pressure in it varying from 1 to 5cm.We also measured saturated hydraulic conductivity of the soil using the constant-head method and then used it as a benchmark to test the results measured from the infiltrometer.Water flow under both methods was described by the Wooding and Philip model.【Result】The hydraulic conductivity measured using the constant head was more accurate and repeatable.The saturated hydraulic conductivity of the crust and soil matrix was 74.00 cm/d and 12.00 cm/d respectively.The indexes of cumulative water infiltration,steady infiltration rate,infiltration rate and hydraulic conductivity of the crust and soil matrix measured by the infiltrometer decreased with the increase in the negative pressure.Using the saturated hydraulic conductivity measured from the infiltrometer,the Philip model reproduced the infiltration process more accurately,despite the effect of the negative pressure.Fitting the results to the van Genuchten formula revealed that the parametersαand n were 0.039 cm and 2.72 respectively for the crusts,and 0.024 cm and 2.83 respectively for the soil matrix.【Conclusion】Negative pressure in the infiltrometer affects saturated hydraulic conductivity calculated using the measured data from crusted soil,and should be considered in data analysis.

关 键 词：微型盘式入渗仪 结构结皮 沉积结皮 土壤饱和导水率 van Genuchten参数 

分 类 号：S152.7[农业科学—土壤学]