Results 181 to 190 of about 34,019 (235)

Spatial Variability of Unsaturated Hydraulic Conductivity

Soil Science Society of America Journal, 1971
Abstract Spatial variability of unsaturated hydraulic conductivity was studied for 40 ha of Pima clay loam. Calculations of hydraulic conductivity were based on the moisture release data using a modified Millington‐Quirk equation.
J. G. Stockton, A. W. Warrick
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Unsaturated Hydraulic Conductivity of Landfilled Waste

Unsaturated Soils 2006, 2006
Unsaturated flow modelling of landfill hydraulics is a potentially valuable tool for the prediction of leachate discharge rates, design of leachate control systems and simulation of biodegradation in engineered landfills. Such an approach requires information on the moisture retention and hydraulic properties of waste, usually in the form of empirical ...
Y. K. Kazimoglu, J. R. McDougall, I. C. Pyrah   +2 more
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Measurement of Subsurface Unsaturated Hydraulic Conductivity

Journal of Irrigation and Drainage Engineering, 2000
Measurement of unsaturated hydraulic conductivity is needed for precise control of water and solutes in the vadose zone. Because of the spatial variation of soils, a large number of surface and subsurface measurements are needed to characterize a field. In this work, permeameters were developed and tested for estimating subsurface unsaturated hydraulic
D. F. Holland, M. Yitayew, A. W. Warrick
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Simple Laboratory Measurement of Unsaturated Hydraulic Conductivity

Journal of Irrigation and Drainage Engineering, 1987
A simple method called “upward infiltration method” is described for using common soil laboratory equipment to measure unsaturated hydraulic conductivity of soil samples in a short time. The method is based on measurement of water absorption rates under controlled tensions, which leads to an estimate of soil hydraulic conductivity during the wetting ...
Zohrab A. Samani, L. S. Willardson
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BIMODAL POROSITY AND UNSATURATED HYDRAULIC CONDUCTIVITY

Soil Science, 1991
Soil water characteristic curves determined on undisturbed soil samples in the laboratory were used for the calculation of the unsaturated conductivity function K(h). This computed K(h) was compared to the unsaturated conductivity data measured directly in the field.
HEINRICH OTHMER, BERND DIEKKRÜGER, MIROSLAV KUTILEK   +2 more
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Microbiotic Crust Influence on Unsaturated Hydraulic Conductivity

Arid Soil Research and Rehabilitation, 1999
Microbiotic crusts occur extensively in rangeland soils . Developed by filaments of cyanobacteria and algae , and thalli of lichen and moss entanglement of soil particles , they create a physical discontinuity in the surface profile with greater concen trations of clay , silt , and potentially hydrophobic organic matter.
J. D. Williams, J. P. Dobrowolski, N. E. West   +2 more
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Rapid Estimate of Unsaturated Hydraulic Conductivity Function

Soil Science Society of America Journal, 1978
Abstract From results of Reichardt, Nielsen, and Biggar and of Russo and Bresler, it is inferred that a laboratory horizontal infiltration experiment with air‐dry soil yields an estimate of the saturated‐unsaturated hydraulic conductivity function given by K(h) = 0.27 m
E. Bresler, D. Russo, R. D. Miller
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Predicting Unsaturated Hydraulic Conductivity from Soil Texture

Journal of Irrigation and Drainage Engineering, 1987
A total of 14 methods to predict K(h) from soil texture andor other data were tested. Nine of the methods involved first predicting K(h) from texture andor other data, then using a method to predic...
Lynne Alexander, R. Wayne Skaggs
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SATURATED AND UNSATURATED HYDRAULIC CONDUCTIVITY OF SWELLING CLAYS

Soil Science, 1986
The theory of water flow in swelling clays may be developed in a space coordinate system at rest, assuming that the flux of clay particles can be defined by the space gradients of potential responsible for the movement of clay particles, which is related to the gradients of water potential.
M. NAKANO, Y. AMEMIYA, K. FUJII
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Hydraulic Conductivity Assessment of Unsaturated Soils

1994
Predicting the direction and rate of contaminant transport in the vadose zone requires quantification of soil hydraulic properties. For many problems, the most appropriate approach is to assume that the contamination is moving with the water phase. Therefore, the unsaturated hydraulic conductivity is the most important property governing water movement
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