盐碱土入渗下修正Green-Ampt模型参数确定与验证  

Parameter determination and verification of improved Green-Ampt model under saline-alkali soil infiltration

作　　者：陈俊英[1,2] 何旭佳 杨亚龙 白旭乾 李毅[2] 谢林林 Chen Junying;He Xujia;Yang Yalong;Bai Xuqian;Li Yi;Xie Linlin(Key Laboratory of Agricultural Soil and Water Engineering,Ministry of Education,Northwest A&F University,Yangling 712100,China;College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China;College of Science,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学旱区农业水土工程教育部重点实验室,杨凌712100 [2]西北农林科技大学水利与建筑工程学院,杨凌712100 [3]西北农林科技大学理学院,杨凌712100

出　　处：《农业工程学报》2021年第12期125-133,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(51409221,51979234)。

摘　　要：为进一步探究盐碱土的入渗机理,实现科学的盐碱土农业生产与灌溉,基于传统Green-Ampt模型,根据盐碱土的入渗特性引进扩散率,并结合对土壤剖面含率分布的划分假定对模型进行修正。利用5种盐碱土进行一维积水入渗试验,采用入渗率、湿润锋数据验证该修正模型。结果显示:修正模型模拟值与实测值的一致性良好,进行相关分析得到5种盐碱土入渗率R^(2)平均值为0.983,平均绝对误差均小于0.05 cm/min;湿润锋R^(2)平均值为0.868,平均绝对误差均小于3.50 cm。将修正模型参数饱和导水率、湿润锋面基质吸力值与盐碱土盐分离子含量进行相关分析,结果显示基质吸力值随K^(+)+Na^(+)含量的减少而减小,饱和导水率随K^(+)+Na^(+)含量的减少而增大。该修正模型经验证可应用于不同盐渍化程度的盐碱土入渗过程模拟,从而为深入盐碱土水分入渗机制研究与加快盐碱土农业生产提供理论支持。Based on the traditional Green-Ampt infiltration model,the diffusion rate D(θ)was introduced to improve the model according to the saline soil infiltration characteristics.Considering the presence of air in the soil,the method of linearizing D(θ)expression was adopted to improve the accuracy of the model parameters.Five types of saline-alkali soils were used to conduct five one-dimensional water infiltration experiments.The data of infiltration rate and wetting front were used to verify the applicability of the improved model,and the result showed that the simulated values of the improved model were in good agreement with the measured values.The average value of the R^(2) for the five saline-alkali soil infiltration rate was 0.983,and all the average absolute errors for the five saline-alkali soil infiltration rate were less than 0.05 cm/min.The average value of the R^(2) for the five saline-alkali soil wetting front was 0.868,and all the average absolute errors for the five saline-alkali soil wetting front were less than 3.50 cm.The simulation data of the improved Green-Ampt model were not completely consistent with the measured value,which was due to the combined influence of various factors,the main reason was that the test data was easy to be changed by environmental disturbance.Notably,none of the model data is completely consistent with the experimental data.The experimental data was affected by the disturbance of environmental factors,and were often different from the theoretical results.The experimental data was different from the theoretical results due to the interference of environmental factors.Soil characteristics was the main factors affecting model parameters,and the model parameters of the improved model was affected by K^(+)+Na^(+)content of saline-alkali soil.The correlation between salt content and model parameters was also explored,the result showed that the suction head value decreased with the decrease of the content of K^(+)+Na^(+),and the saturated hydraulic conductivity increased with t

关 键 词：入渗 含水率 盐碱土 基质吸力 GREEN-AMPT模型 

分 类 号：S152.7[农业科学—土壤学]