Water balance
Growers irrigate their fields to supply water. To irrigate, farmers construct canals, ditches or dig out tube wells, and divert the water from permanent sources. It is reported loss of 2-3 quintals per hectare due to each week delay in first irrigation for crown root initiation stage.
In hydrology, a water balance equation can be used to describe the flow of water in and out of a system. Water balance can also refer to the ways in which an organism maintains water
in dry or hot conditions.
A general water balance equation is:
P = Q + E + ΔS
Where,
P is precipitation, Q is runoff , E is evapotranspiration and ΔS is change in storage( in soil or the bed rock).
Applications
- Evaluate the components of the hydrologic cycle
- Snowmelt simulation
- Climate change impact assessment
- Flow forecasting and project design
- Assess agricultural water management
The general water balance reads:
inflow = outflow + change of storage