宁夏黄灌区灌淤土水力参数研究

对宁夏黄灌区灌淤土水力参数进行了较为系统的研究.研究结果表明,原状土与扰动土饱和导水率变化范围分别为10～100 cm/d和3～50 cm/d.原状土饱和导水率随土壤剖面变化规律与扰动土一致:随着土壤深度的增加,饱和导水率呈现高低往复变化.原状土和扰动土的饱和导水率受粘粒含量、密度、孔隙度影响较大,受有机质含量影响较小...

Study on Hydraulic Parameters of Irrigating Warped Soil in Ningxia Irrigation Area

A systematic research on hydraulic parameters of irrigating warped soil in Ningxia irrigation area is shown in this article.The results indicated as: the variation of saturated hydraulic conductivity of undisturbed soil and disturbed soil is 10~100 cm/d and 3~50 cm/d respectively.The dynamics of saturated hydraulic conductivity along the soil profile of the undisturbed soil is consisting with that of the disturbed soil: the saturated hydraulic conductivity presents reciprocating change with the increase of depth.The saturated hydraulic conductivity of undisturbed soil and disturbed soil are affected by clay content,bulk density,and porosity,except organic matter content.The saturated hydraulic conductivity of undisturbed soil is bigger than disturbed soil,with the general ratio of 2~5 times,and the variability is bigger too.Tendencies of soil water retention curves of all soil layers are similar,the soil volumetric water content decreased with the increase of soil water suctions,and it will stable when the suction reach a certain value,the soil water retention curve is affected by the clay content dramatically.The soil moisture diffusivity of all soil layers is changeable from 1.0×10-3~6 cm2/min,and the soil moisture diffusivity of upper soils are far smaller than the lower's.Relationship between soil moisture diffusivities and soil volumetric water content in every soil layer are sharply positive exponential function,which was fitted by the empirical equation: D(θ)=aebθ.The soil moisture diffusivity is affected by soil clay content,porosity,soil bulk density,and organic matter content.