Which factors influence the movement of water through soil?

Which factors influence the movement of water through soil?

There are mainly two soil conditions that affect the water vapour movement namely moisture regimes and thermal regimes. In addition to these, the various other factors which influence the moisture and thermal regimes of the soil like organic matter, vegetative cover, soil colour etc.

How does air and water influence soil?

Air can fill soil pores as water drains or is removed from a soil pore by evaporation or root absorption. The network of pores within the soil aerates, or ventilates, the soil. This aeration network becomes blocked when water enters soil pores.

What is the movement of water through the soil called?

Infiltration: The process of water entering the soil surface is known as infiltration. Infiltration Rate: Infiltration is a very dynamic process. Water applied to the surface of a relatively dry soil infiltrates quickly due to the affinity of the soil particles for water.

How does water move through clay soil?

The clay soil has small pores and attracts water more strongly than the sandy soil with large pores, but transmits it more slowly. When the soils are wet, water moves through the larger pores between the sand particles faster than it moves through the smaller pores between the clay particles.

What is soil water and soil air?

The pore spaces of the soil must be filled by either air or water. When the water comes in, air goes out; when the water goes out, air comes in. Soil water may be divided into three classes: Gravitational water is that water which percolates through the soil and drains out by the force of gravity.

How does water move through the ground?

Water moves underground downward and sideways, in great quantities, due to gravity and pressure. Eventually it emerges back to the land surface, into rivers, and into the oceans to keep the water cycle going.

How does soil structure affect water erosion?

As the proportion of clay increases, the size of the pore space decreases. This restricts movement of water through the soil and increases the risk of runoff. Soils with low clay content are less cohesive and are inherently more unstable. These soils are at greater risk of erosion by water and wind.

How does water move through the soil?

When soil water moves mainly due to gravity, which is at moisture potentials greater than -1/3 bar, the movement is called “Saturated flow”. Saturated flow starts with water infiltration, which is the movement of water into the soil when precipitation of irrigation water is on the soil surface.

What are the two forces responsible for the movement of soil?

The two forces responsible for this movement are the attraction of soil solids for water (adhesion) and capillarity. Under field conditions this movement occurs when the soil macropores (non- capillary) pores with filled with air and the micropores (capillary) pores with water and partly with air.

How does soil size affect the rate of water flow?

The flow of water is proportional to the size of the soil particles. The larger the size of the particles, the more rapid is the rate of movement of water. Sandy soils generally have higher saturated conductivities than fine textured clay soils.

How to modify the equation for the movement of water through soil?

Due to presence of air phase in the soil system of unsaturated conditions the equation for the movement of water through the saturated soil can be modified as follows by introducing a dimensionless factor λ with k. The factor λ varies from 0 to 1 and disappears when the soil is saturated.