0 views
0 votes
0 votes

What is Soil Water Movement?

by
2.2k points

1 Answer

0 votes
0 votes
 
Best Answer

i) Saturated Flow

ii) Unsaturated Flow

Saturated flow: This occurs when the soil pores are completely filled with water. This water

moves at water potentials larger than – 33 kPa. Saturated flow is water flow caused by gravity’s

pull. It begins with infiltration, which is water movement into soil when rain or irrigation water is

on the soil surface. When the soil profile iswetted, the movement of more water flowing through

the wetted soil is termed percolation.

(ii) Unsaturated Flow

It is flow of water held with water potentials lower than- 1/3 bar. Water willmove toward

the region of lower potential (towards the greater “pulling” force). Ina uniform soil this means that

water moves from wetter to drier areas. The water movement may be in any direction. T h e

rate of flow is greater as the waterpotential gradient (the difference in potential between wet

and dry) increases andas the size of water filled pores also increases. The two forces responsible

for thismovement are the attraction of soil solids for water (adhesion) and capillarity.Under

field conditions this movement occurs when the soil macrospores (non-capillary) pores with filled

with air and the microspores (capillary) pores with waterand partly with air.

Entry of Water into Soil

Infiltration: Infiltration refers to the downward entry or movement of water intothe soil surface

 It is a surface characteristic and hence primarily influenced by the conditionof the

surface soil.

 Soil surface with vegetative cover has more infiltration rate than bare soil

 Warm soils absorb more water than colder ones

 Coarse surface texture, granular structure and high organic matter content insurface soil,

all help to increase infiltration

 Infiltration rate is comparatively lower in wet soils than dry soils

Percolation: The movement of water through a column of soil is calledpercolation. It is

important for two reasons.

i) This is the only source of recharge of ground water which can be used throughwells for

irrigationii) Percolating waters carry plant nutrients down and often out of reach of plantroots

(leaching)

 In dry region it is negligible and under high rainfall it is high

 Sandy soils have greater percolation than clayey soil

 Vegetation and high water table reduce the percolation loss

Permeability: It indicates the relative ease of movement of water with in the soil. The

characteristics that determine how fast air and water move through the soil is known as

permeability. The term hydraulic conductivity is also used which refers to the readiness with

which a soil transmits fluids through it

by
2.2k points

Related questions

1 answer
0 votes
0 votes
5 views
Preeti priya yadav Asked Dec 8, 2022
8 views
Preeti priya yadav Asked Dec 8, 2022
by Preeti priya yadav
2.2k points
1 answer
1 vote
1 vote
8 views
Preeti priya yadav Asked Dec 8, 2022
8 views
Preeti priya yadav Asked Dec 8, 2022
by Preeti priya yadav
2.2k points
1 answer
0 votes
0 votes
8 views
1 answer
0 votes
0 votes
0 views
1 answer
0 votes
0 votes
4 views
Puja Kumari Asked Jan 4, 2023
6 views
Puja Kumari Asked Jan 4, 2023
by Puja Kumari
12.8k points
1 answer
0 votes
0 votes
6 views
1 answer
0 votes
0 votes
6 views
WELCOME TO ANSWER AVENUE, WHERE YOU CAN ASK QUESTIONS AND RECEIVE ANSWERS FROM OTHER MEMBERS OF THE COMMUNITY.

Categories