Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Agricultural Engineering


Permeability is the physical property of soil which enables it to pass or conduct air or water through is macropores. This should not be confused with the infiltration rate, a term expressing the rate at which water will enter the soil surface. Whereas the infiltration rate is influenced by the hydraulic slope, permeability is not (12, p. 153)*. A term which is often confused with permeability is hydraulic conductivity. Hydraulic conductivity is a velocity term, or (L/T), expressing the rate at which a fluid passes through the soil. The specific need for hydraulic conductivity and permeability measurements is to determine the rate at which water will move through soil. Thus the information on these measurements is indispensable in sound planning of drainage and irrigations systems. This study will deal primarily with devising a method of measuring the hydraulic conductivity of soil. Frequently the horizontal permeability of an alluvial soil is 10 times greater that the vertical permeability because under water the particles are deposited with most of their flat surfaces parallel to each other. The presence of tight clay layers will also further decrease the relative vertical permeability. Therefore, it is important to recognize the nonhomogeneous as well as the anisotropic nature of the soil when permeability measurements are being taken.

Library of Congress Subject Headings

Soil permeability
Soil percolation




South Dakota State University