Soil Permeability

The ability of soil to allow flow of water through it is called as permeability of soil.

Soil permeability. Soil permeability also termed hydraulic conductivity is measured using several methods that include constant and falling head laboratory tests on intact or reconstituted specimens. Also partially saturated soils contain air pockets that are formed due to entrapped air or due to air liberated from the percolating water. Water does not flow in a straight line but in a winding path. Alternatively permeability may be measured in the field using insitu borehole permeability testing e g and field pumping tests.

Where v is the apparent fluid velocity through the medium i is the hydraulic gradient and k is the coefficient of permeability hydraulic conductivity often expressed in m s. The permeability of coarse sand may be more than one million times as much that of clay. A pond built in impermeable soil will lose little water through seepage. It was studied by allen hazen that the coefficient of permeability k of a soil is directly proportional to the square of the particle size d.

In one way increase in the degree of saturation increases the area of flow and hence increases the permeability. Thus permeability of coarse grained soil is very large as compared to that of fine grained soil. Thus the coefficient of permeability or simply permeability is defined as the average velocity of flow that will occur through the total cross sectional area of soil under unit hydraulic gradient. Soil permeability is the property of the soil to transmit water and air and is one of the most important qualities to consider for fish culture.

Tandlguru ks1 science knowledge organisers bundle. Permeability of the soil is directly proportional to the degree of saturation of the soil. Free 8 popular paid resources. As a result of the poor drainage salt lakes can form like those in the western united states.

Flow of water in soil takes place through void spaces which are interconnected. It is often represented by the permeability coefficient k through the darcy s equation. When hydraulic gradient is unity k is equal to v. Soil permeability is the ease with which gases liquids or plant roots penetrate or pass through a bulk mass of soil or a layer of soil glossary of soil science terms 1997.

Dimensions are same as of velocity cm sec. It is very important factor for the structures which are in contact with water. Soil profile and permeability. If a soil contains flocculated structure the particles are in random orientation and permeability is more in this case.