A channel of canal where water flows under the influence of gravity is called _______

🔑Key Points:
Flow channel
These are also called gravity irrigation.
It is the type of irrigation in which water is available at a higher level to enable supply to the land by gravity flow. Hence, Option 4 is correct.

🔴Additional Information:
Lift Irrigation: Involves lifting groundwater using mechanical means (like pumps) when water supply is too low for gravitational flow.
Drip Irrigation: Also known as trickle irrigation; water is directly applied to the plant root zone using a drip nozzle, minimizing evaporation and percolation losses; considered the most efficient method.
Sprinkler Irrigation: Water is applied through a network of pipes and pumps; suitable for irregular or rolling topography, high water tables, situations where water is not easily available, and for both permeable and less permeable soils.