| 引用本文: | 任健,张吴平,王国芳,等.基于离心机法获取定体积质量下的土壤水分特征曲线[J].灌溉排水学报,2020,(1):-. |
| ren jian,zhang wuping,wangguofang,et al.基于离心机法获取定体积质量下的土壤水分特征曲线[J].灌溉排水学报,2020,(1):-. |
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| 摘要: |
| 【目的】克服离心机法测定土壤水分特征曲线时“变体积”的缺陷，实现用离心机法获取扰动土壤准确的土壤水分特征曲线。【方法】选取了山西省16种粒径组成、有机质量差别显著的扰动土壤作为研究对象，采用离心机法测定了初始体积相同的各土壤样品在不同转速下的土壤体积含水率、动态变化的土壤体积；采用多元非线性回归模型，描述了以土壤体积含水率、粒径组成、体积质量和有机质作为自变量描述土壤水吸力的函数关系，并对模型进行了验证与评价。【结果】土壤水吸力的自然对数函数可以表示为土壤砂粒质量分数、粘粒质量分数、土壤体积质量和含水率乘积以及有机质质量分数等土壤属性的线性函数，模型的决定系数达到0.740；模型建模样本平均相对误差为14.460 %，验证样本平均相对误差为13.237 %，模型预测精度较高；同时发现土壤属性对于曲线的形状与走势的影响不能忽视，其中砂粒质量分数、土壤体积质量和含水率乘积与土壤水吸力呈负相关，粘粒质量分数、有机质质量分数与土壤水吸力呈正相关。【结论】因此，本方法构建的模型更符合实际情况，能够提高土壤水力学参数的精度，同时可以克服离心机测量土壤水分特征曲线体积变化的缺点，得到更合理的土壤水吸力和土壤含水率的关系。 |
| 关键词: 土壤水分特征曲线；多元非线性预测模型；离心机法；仿真数值模拟 |
| DOI： |
| 分类号:S152.7+1 |
| 基金项目: |
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| Estimation of Soil Water Retention Curve Under Constant Volume Mass Obtained Based on Centrifuge Method |
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ren jian1, zhang wuping1, wangguofang1, huang ming jing2, qiao lei1
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1.Shanxi Agricultural University,College of Resources and Environment;2.Arid Farming Research Center, Shanxi Academy of Agricultural Sciences
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| Abstract: |
| 【Objective】This paper aims to overcome the defect in the "variable volume" with disturbed soil of determination of soil water retention curve (SWRC) by centrifuge method.【Method】We took the SWRCs and the 16 kinds of particle size compositions,organic matter(OM) content in Shanxi significant difference of disturbed soil as the research objects, used the same centrifuge method to determine the initial volume of soil samples under different rotational speed of the dynamic variation of the soil volumetric water content and volume. The multiple nonlinear regression model was used to describe the functional relationship of soil suction with soil volume moisture content, particle size composition,volume mass and OM as independent variables,and the model was verified and evaluated. 【Result】The natural logarithm function of soil suction could were expressed as a linear function of soil sand mass fraction,clay mass fraction,product of soil volume mass and water content,and OM mass fraction; the decision factor of model reached 0.740;The average relative prediction error of the modeling samples was 14.460%, and the average relative prediction error of the verification samples was 13.237%, which was of high accuracy; the model establishes the SWRC under the influence of various soil attributes, and the influence of various soil attributes on the shape and trend of the curve were not be ignored, the sand mass fraction, soil volume mass and water content were negatively correlated with soil water suction, clay mass fraction and organic matter mass fraction were positively correlated with soil water suction.【Conclusion】The the model constructed by this research method is more agreement with the actual situation,and can improve the accuracy of soil water movement, and can get a more reasonable relationship between soil suction and soil water content under the change of volume of SWRC measured by centrifuge method.This research can provide the basic parameters for studying soil water float. |
| Key words: Soil water retention curve; Multiple nonlinear prediction model; Centrifuge method; Virtual numerical simulation |
