Water Resources

Water Resources refers to the artificial application of water from rivers, tanks, canals and
other artificial projects for the purpose of cultivation and agricultural purposes

Need for Water

→ India being an agricultural country there Pore water is needed for agricultural purposes
irrigation.

→ Its needed for domestic as well as Industingical purposes.

→ Requirement of water is high due to its huge population.

Why is irrigation required?

1 The rainfall in India is seasonal, erratic, unevenly distributed

2.⁠⁠Reduces the over dependence on monsoon.

3.⁠⁠Increases agricultural productivity.

4.⁠⁠Bring more land under cultivation.

2 Creates Job Opportunities.

6 Develops electricity and transport facilities

7 Controls floods and prevents droughts

Need for Irrigation

→Climatic Roosen

1 Rainfall is distributed unevenly

3 Rainfall is seasonal.

3 India has multiple cropping seasons

4 Uncertain and erratic rainfall

5.⁠⁠Late arrival and early departure

→ Crop Reason

1.⁠⁠Kharif, Rabi and Zaid crops require heavy irrigation. (Summer crops)
2.⁠⁠Certain crops are water exhausting crops rice, jute, sugarcane

2.⁠⁠Due to green revolution development of high yielding varieties of seed [Irrigation is a part
of green revolution]

WATER Resources

1. Surface Water River (Lakes, ponds, backwaters and lagoons) {is used for irrigation)
2. Ground Water Tube wells, to pullout the ground water is needed for soil irrigation

Means for Irrigation

1. Primitive Methods - wells, inundation canals, tanks

2. Modern Methods
a. Non-Conventional- Furrowing, drift sprinkler. bamboo Irrigation
b. Conventional- Tube wells, perennial Canals

1. Primitive Methods.

Wells
Wells are holes dug in the ground which are about 3-5m deep to obtain sub-soil water.

Q. Why is Well irrigation only present in Northern-India?

Ans) Alluvial soil is soft and can be easily dug Rainfall leads to replenishment of
groundwater. Agricultural land makes crops absorb water which also replenishes the water.

Why does Peninsular India not have Well Irrigation?

Ans)

For Wells to develop:

● Sufficient groundwater is available
● Soil is soft enough to enable the digging of wells

Advantages
● Simple and cheap source of irrigation hence price affordable
● Independent source of irrigation, the farmer can use it anytime
● Does not turn the soil saline and alkaline
● Can be dug at any convenient place on the field.
● No added expenses to pull out water the domestic animals can be used

Disadvantages
● Can irrigate only limited area
● Dry up during the most required season (summer)
● Is not possible where water is brackish (salty)
 ● Time consuming process

Distribution;
UP because of ganga plain, MP, rajasthan and punjab

Inundation Canals
Are canals that are taken out directly from the rivers without making any kind of barrages
and dams

Canals are the 2nd largest source of irrigation.

Advantages
● Operational without any cost
● Silt deposition (comes from perennial rivers)

Disadvantages
● Remains operational during rainy season ONLY
● No system to regulate the flow of water can only be done by using lock gates or weirs

Distribution
Punjab haryana sutlej ganga plains and brahmaputra valley

Tanks
Constructed bu building earthen walls across a river or a depression behind which water
collects.

Conditions required
● Hard, impermeable layer of rock below so that water does not percolate in
● Some means of filling up the tanks repeatedly.

Advantages
● Allows the surface water during the monsoon to be stored and used later
● Easy to construct and economical
● Raises the underground water level as some (percolation is there
● It is prevalent in the Deccan plateau region where water is collected and used later
for irrigation.

Disadvantages
● Uses up large areas of land which would otherwise be used for agriculture
● Dries up in summer and so is not of much use
● Water gets evaporated quickly as it is shallow
● Difficult to carry water from the tanks to the fields

Tanks are popular in deccan region because-

Natural depressions are found, non porous rocks prevent percolation of water, population
and agricultural fields are scattered rainfall is season.

Distribution; Andhra Pradesh, Tamil Nadu Karnataka, MP

Tube Wells
They are deep wells which are more than 5m deep from which water is lifted using a
pumping set operated by an electrical motor or a diesel engine.

Conditions required

● Sufficient ground water

● Should be nearly 15m deep( if deeper cost will be more)
● Regular supply of cheap electricity
● Soil should be fertile so that there is a demand for irrigation

Advantages
● Tube wells can irrigate 10 times the area (2 hectares) irrigated by ordinary wells(0.2
hectares)
● A electric motor and diesel engine are used water can be extracted from a great
depth
● Suitable for areas where canal irrigation is not possible
● Independent source of irrigation
● Chemicals mixed with water adds to the soil fertility
●
Disadvantages
● Irrigates relatively limited areas in comparison to canals
● Farmers have to spend money on diesel or electricity
● Brackish tube wells are unfit for cultivation
● Leads to depression of groundwater resources

Distribution MP,UP, punjab rajasthan haryana

Perennial canals
They are affective sources of irrigation in areas of low relief deep fertile soils perennial
sources of waters and extensive agricultural land

Advantages
● Perennial source of irrigation
● Modern but conventional
● Carries sediments which gets deposited in the fields and adds to the soil fertility
● Canals are a part of the multipurpose project thus provides cheap irrigation if 2-3
farmers use its expensive

Disadvantages
● Leads to water logging
● Excessive flow of water increases the alkaline salt or causes effervescence which
makes the soil unsuitable for farming
● Turns the surrounding areas marshy and leads to the breeding ground for other
diseases

Distribution UP, punjab west bengal haryana bihar

Non Conventional

● Common advantages
● Suitable for all types of soil
● Method is independent of topography
● Water is not lost through seepage and evaporation
● Fertilisers and pesticides can be easily added

Common disadvantages
● High operational cost (investment)
● Excess watering may cause waterlogging

1. Sprinkler Irrigation
Irrigates the field drop by drop thus widely used
Distribution- Karnataka tamil nadu punjab and haryana

2. Drip irrigation trickle irrigation or micro or localised irrigation

Water is sent directly to the roots

Advantages
● Reduces soil erosion
● Disadvantages
● Might lead to leeching
● Cannot be utilised in cold areas

Distribution- Karnataka rajasthan and maharashtra

3. Bamboo irrigation
A bamboo is cut halfway and used as a pipe to transfer water

Advantages
● It does not need any fuel or power hence its economical
● It can be implemented in regions where bamboo is available free or at low cost

Disadvantage
The Bamboo cannot be used again

Distribution- North east india. Meghalaya, manipur because of the extensive bamboo forests