Types of Water Irrigation Engineering

Types of Water in Irrigation System

1. Gravitational Water
2. Capillary Water or Available Water
3. Hydroscopic Water

The moisture content expressed as percentage at ultimate witting point is called "Hydroscopic Coefficient"

1. Gravitational Water
It consists of two parts
i) amount of moisture absorbed from atmosphere by the soil grains.
ii) thin film of moisture sticking to the soil grain which can't be extracted by the plant.
2. Capillary Water or Available Water
the amount of moisture stored in capillary pores which can be extracted by the plant is called capillary water or available water.
Saturation capacity a state where the all voids are filled with moisture.
Field capacity amount of moisture retained in the soil against pull of gravity.
3. Hydroscopic Water
thin layer of water surrounding the soil grains which the roots of plants cannot absorb.