水质对土壤水分扩散率的影响

EFFECTS OF WATER QUALITY ON SOIL WATER DIFFUSIVITY

本文实验研究了水质对土壤水分扩散率的影响。实验结果表明,土壤水分扩散率随钠吸附比(SAR)的增大而减小,随着电导率(EC)的增大而增大;SAR对土壤水分扩散率的影响随着EC的增大而减小,EC≥5时,SAR对土壤水分扩散率的影响很小;EC对土壤水分扩散率的影响随着SAR的增大而增大;SAR≤5时,EC对土壤水分扩散率的影响很小。含水量大于0.3时,含水量的减小使得水质对土壤水分扩散率的影响变弱。指数模型可以很好的拟合土壤水分扩散率与含水量的关系;文中数据拟合的相关系数(R2)均大于0.93,并且R2有随着水质的变差而变小的趋势;拟合方程的截距反应了土壤水分扩散率对水质变化的敏感性,截距随SAR的增大而减小,随EC的增大而增大。

Based on the data of experiment,effects of water quality on soil water diffusivity D（θ） is analyzed.It indicates that D（θ） decreases with increasing sodium absorption ratio（SAR） value,and the difference of D（θ） decreases with increasing electric conductivity（EC） value among all SAR levels.When EC≥5,the difference is very small.D（θ） increases with increasing EC value,and the difference of D（θ） increases with increasing SAR value among all EC levels.When SAR≤5,the difference is very small.When soil water content（θv） is bigger than 0.3,effects of water quality on D（θ） is less significant with decreasing θv.Relationship of D（θ）and θv can be well fitted using exponential model and the correlation coefficient（R2） is bigger than 0.93.The Value of R2 decreases with water quality getting worse.The sensitivity of D（θ） changing with water quality can be interpreted by the intercept of fitting equation,and the intercept decreases with increasing SAR value,increasing with increasing EC value.