Water Resources — Part 2: Irrigation: visual lesson, ICSE Class 10 Geography (H.C.G. Paper 2)

Lesson

Water for the fields

Part 2 — irrigation is the artificial supply of water to crops. It turned the dry fields of Punjab into India’s granary and lets farmers in Tamil Nadu grow a second crop. India uses several methods, each suited to its region.

In this lesson you will

Explain why irrigation is needed in India
Explain why tank irrigation is common in peninsular India and tube wells in the northern plains
Compare perennial and inundation canals and state disadvantages of canal irrigation
Explain how drip and sprinkler irrigation save water

Table of irrigation methods and typical regions
Method	Typical region
Wells and tube wells	Northern plains, Gujarat
Tanks	Tamil Nadu, Karnataka, Telangana
Canals	Punjab, Haryana, Uttar Pradesh, river deltas
Drip and sprinkler	Maharashtra, Rajasthan, Karnataka

Concept

Why irrigation is needed in India

Seasonal rain: most rain falls in three to four months; rabi crops grow in the dry winter. Uncertain monsoon: onset may be late, with long breaks or failure. Uneven rain: large areas such as Rajasthan, Gujarat and the rain-shadow Deccan get too little. Thirsty crops: rice, sugarcane and jute need much more water than rain gives in many areas. Multiple cropping and high-yielding seeds need an assured water supply. Porous soils such as sandy and red soils do not hold water.

Table of reasons for irrigation with an example of each
Reason	Example
Seasonal rain	Wheat grown in dry winter
Uncertain monsoon	Breaks in July harm young rice
Low rainfall	Western Rajasthan
Thirsty crops	Sugarcane in Maharashtra
High-yielding seeds	Need regular water

Concept

Wells and tube wells

Wells are pits dug down to the water table; water is lifted by hand, by the Persian wheel or by pumps. They are cheap, simple and owned by individual farmers, but irrigate small areas and may dry up. Tube wells are deep, narrow holes bored into the aquifer, with a pipe and an electric or diesel pump; they can lift large amounts of water from great depths. Wells and tube wells together are the leading source of irrigation in India (as of the early 2020s), especially in Punjab, Haryana, Uttar Pradesh, Bihar, Gujarat and parts of Rajasthan.

Cookies