What is Irrigation?
Irrigation is the process of applying controlled amounts of water to plants at needed intervals.
What is the need for irrigation?
The success of crops in most areas is dependent on timely monsoons and sufficient rainfall spread through most of the growing season.
Hence, poor monsoons cause crop failure. Ensuring that the crops get water at the right stages during their growing season can increase the expected yields of any crop. Therefore, many measures are taken to bring more and more agricultural land under irrigation.
Which are the types of irrigation systems adopted?
Owing to varied climatic conditions, several different kinds of irrigation systems are adopted to supply water to agricultural lands depending on the kinds of water resources available. These include wells, canals, rivers and tanks.
Let us look at each one of them.
Wells: A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water.
There are two types of wells depending on the method by which it was created by humans.
- Dug wells: A dug well in simple words is an open hole made for the sole purpose of obtaining water for a simple household. The water is taken out manually with the help of ropes and a bucket.
Dug wells are commonly found in villages and they do not need heavy types of machinery to be dug. A simple shovel can help create a dug well.
- Tube wells: A tube well consists of a pipe or a tube that is placed inside the ground. The ground is dug with the help of a This machine keeps drilling until it hits the underground water table. This water table would then ensure a constant supply of water. As the hole is quite deep, water can only be taken out with the help of a ‘water pump’. These tube wells are majorly used for irrigation purposes as they have the underground water at their disposal.
Canals: A canal system is an artificial man-made river system. They are cemented pipe-like structures that form a network in a particular area. These canals receive the water from a nearby water reservoir or directly from a river. This water is then carried through these canals to the nearby fields. The main canal is distributed into several smaller canals.
Canal
River Lift Systems: The places where canals cannot be built farmers opt for the River lift system. The building of a canal system involves labour and finances and hence some villages cannot afford building canals. In such cases, river lift systems come to the rescue.
In a River lift system, water is directly drawn from the rivers for supplementing irrigation in regions near the river. So, the water is directly taken from the rivers. This requires the use of pumps. Water is taken from the main river to a centralised delivery chamber. Water is then made to flow with the help of gravity to the other parts of the field.
River Lift System
Tanks: Tanks act as small storage reservoirs. They intercept the surface runoff and collect the water. This water can then be used to irrigate the fields. This method is now widely used and we know it as Rainwater harvesting. Rainwater can be allowed to seep into the soil where it will be stored in the underground water table. All societies and settlement can employ such techniques of water harvesting. This initiative will ensure a constant supply of water throughout the year.
Rainwater harvesting
Watershed management: Watershed management is a technique that ensures storage of water as well as prevents surface runoffs.
Let us look at an example here.
Check dams: We could build small check dams; this will enable the water that flows on the surface to seep into the ground. Check dams not only help increase the underground water level but they also help check soil erosion.
