云南红壤水力参数差异较大的原因探究  

Exploration of the reasons for the large difference in hydraulic parameters of red soil in Yunnan Province

作　　者：王莹 李重庆 刘清圣 卢麒麟 WANG Ying;LI Chong-qing;LIU Qing-sheng;LU Qi-ling(College of Water Conservancy,Yunnan Agricultural University,Kunming 650201,China;Engineering Research Center of Green Smart Farmland and Carbon Emission Reduction,Kunming 650201,China)

机构地区：[1]云南农业大学水利学院,昆明650201 [2]云南省高校绿色智慧农田与碳减排工程研究中心,昆明650201

出　　处：《湖北农业科学》2024年第12期24-30,共7页Hubei Agricultural Sciences

基　　金：兴滇人才支持计划项目(XDYC-QNRC-2022-0107);云南省教育厅基金项目(2022Y290)。

摘　　要：为探究造成云南红壤水力参数与周边地区差异较大的原因,分别采集原状土农田以及土地平整后农田的土壤样品,测定红壤的基本水力参数;同时开展持续2 h的田间地表滴灌入渗试验,将土壤剖面分为0~15 cm、15~25 cm、25~40 cm、40~55 cm共4层,基于HYDRUS-1D模型的Kosugi经验模型构建不同反演模型,分析不同反演方式对土壤水力参数的影响。为保障反演模型在田间条件下收敛,将滴头接触半径假定在(1.0±0.2)cm范围采用试错法进行率定,选出精度最高的条件用于后续分析。结果表明,将0.84 L/h灌溉流量通过试错法率定,在滴头接触半径为0.9 cm、上边界定通量为2.75 cm/min的条件下反演模型的模拟精度最高,其R^(2)为0.92618,AIC值为-65.62,BIC值为-62.04;适用于田间红壤的反演方式为将实测各层状土的饱和含水量、残余含水量、饱和导水率固定不变来反演拟合参数,鉴于红壤表层在田间滴灌期间会形成阻水层,表层土壤的饱和导水率也需进行反演。此外,云南原状红壤受地理、紫外线辐射、干湿季节气候等因素影响具有极高的保水性以及较强的透水性,但对土地平整后的农田进行采样或是通过数值模型基于不准确的土壤参数进行反演,可能得出红壤保水性、透水性较差的结论。In order to explore the reasons for the large difference in the hydraulic parameters of red soil between Yunnan Province and the surrounding areas,the basic hydraulic parameters of red soil were measured by sampling in undisturbed soil farmland and farm⁃land after land leveling.At the same time,a two-hour field surface drip irrigation infiltration test was carried out.The soil profile was divided into four layers of 0~15 cm,15~25 cm,25~40 cm and 40~55 cm.Based on the Kosugi empirical model of HYDRUS-1D mod⁃el,different inversion models were constructed to analyze the effects of these methods on soil hydraulic parameters.In order to ensure the convergence of the inversion model under field conditions,the contact radius of the emitter was assumed to be in the range of(1.0±0.2)cm,which was calibrated by the trial and error method,and the conditions with the highest accuracy were selected for subse⁃quent analysis.The results showed that the simulation accuracy of the inversion model was the highest when the irrigation flow rate of 0.84 L/h was calibrated by the trial and error method,the contact radius of the emitter was 0.9 cm and the constant flux of the upper boundary was 2.75 cm/min,and the R^(2) was 0.92618,the AIC value was-65.62,and BIC value was-62.04.The inversion method suitable for red soil in the field was that the fitting parameters were inverted by fixing the measured saturated water content,residual water content and saturated hydraulic conductivity of each layered soil.In view of the fact that the surface layer of red soil would form a water blocking layer during drip irrigation in the field,the saturated hydraulic conductivity of the surface soil also needed to be invert⁃ed.In addition,this study found that the undisturbed red soil in Yunnan Province had high water retention and strong water permeabili⁃ty due to factors such as geography,ultraviolet radiation,and dry and wet season climate.However,sampling of farmland after soil lev⁃eling or inversion based on inaccurate soil parameters

关 键 词：红壤 土壤水力参数 参数反演 地表滴灌 数值模拟 云南省 

分 类 号：S152.7[农业科学—土壤学]