| 摘要: |
| 【目的】建立基于粘粒含量的土壤水分特征曲线预测模型。【方法】设计12种不同粘粒百分含量的质量混合比处理，获得一系列合成土样，通过测定合成土样的土壤水分特征曲线，研究在容重一致的条件下，粘粒含量对土壤水分特征曲线参数和孔隙分布的影响。【结果】在容重为1.55 g/cm3条件下，粘粒含量增加1.9倍，土壤中传导孔隙（0.03~1 mm）体积减少28.6%，储存孔隙（200 nm~0.03 mm）体积增加6倍，土体的持水性增强。合成土样的土壤水分特征曲线参数θs和α均与粘粒含量显著正线性相关，θr与粘粒含量显著负线性相关，n和m均与粘粒含量呈指数衰减关系。【结论】基于粘粒含量确定的土壤水分特征曲线预测模型具有较高的精度，能够快速预测土壤水分特征曲线，预测值与实测值之间绝对误差小于15%。 |
| 关键词: 粘粒含量；土壤水分特征曲线；预测模型 |
| DOI： |
| 分类号:S152.3 |
| 基金项目:：国家自然科学(51869024)；宁夏高等学校一流学科建设项目(NXYLXK2017A03)；宁夏重点研发计划重大项目(2018BBF02022) |
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| Predicting model of Soil Water Characteristic Curve based on Clay Content - the Experimental Study |
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XIA Tian1,2,3,2,4,2, TIAN Juncang1,3
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1.College of Civil and Hydraulic Engineering,Ningxia University;2.China;3.Ningxia Research Center of Technology on Water-saving Irrigation and Water Resources Regulation;4.Center of Engineering Research on Efficient Utilization of Water Resources in Modern Agriculture in Arid Regions Ministry of Education
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| Abstract: |
| 【Objective】The aim of this study is to derive a predicting model of soil water characteristic curve base on clay content.【Method】The soil used for the experiment was the natural sandy soil sieved into two groups. Based on different mass percentage of the above two groups of soil, totally twelve treatments were designed for mixing them homogenously, and a series of mixed soil samples were obtained. Then the soil water characteristic curve for each treatment of combined soil was measured, in order to analyze the effect of clay content on soil water characteristic curve and the pore space distribution. In addition, the quantitative relation between the parameters of the soil water characteristic curve and the clay content were derived.【Result】 The results show that when the clay content increases by 1.9 times, the volume of pore space with effective diameter of 0.03~1 mm i.e. the transmission pore, decreases by 28.6% and that of storages pore (200nm~0.03 mm) increases by 6 times. What’s more, the derived parameters θs and α both show significant positive linear correlation with the clay content. Parameter θr shows significant negative linear correlation with the clay content and parameters n and m both significantly decrease exponentially with clay content. 【Conclusion】 The derived model for predicting soil water characteristic curve based on clay content is of high accuracy, which is quick and reliable for predicting soil water characteristic curve, with the absolute error between predicted and observed water content smaller than 15%. The results obtained in our study will be useful for numerical simulation of water movement through soil. |
| Key words: clay content; soil water characteristic curve; predicting model |
