Answer the following
Question 1
What is irrigation?
Answer
The process of artificial application of water from canals, wells, tube wells,
lakes etc.; to the soil for growing crops is called irrigation.
Question 2
Why is irrigation necessary for a country like India?
Answer
Irrigation is necessary for a country like India because of following reasons:
Monsoon is seasonal and rainfall is erratic, sporadic and unevenly
distributed.
Irrigation is required to grow crops throughout the year as rainfall is
seasonal.
Some crops like paddy, sugarcane and jute need more water which has to be
supplied through irrigation.
Commercialization of agriculture and the pressure of growing population.
With proper irrigation, some crops like rice and wheat can have two growing
seasons in a year.
Question 3
State the different methods of irrigation.
Answer
The different methods of irrigation are classified into two groups:
Primitive Methods
Canal irrigation
Tank irrigation
Wells
Modern Methods
Sprinkler Irrigation
Drip Irrigation
Bamboo Irrigation
Question 4
Of the two types of canal irrigation, which do you think is better? Why?
Answer
The two types of canal irrigation are Inundation canal and Perennial canal.
Out of these, Perennial canal is better because it provides water throughout
the year while Inundation canal provides water only at the time of floods.
Question 5
What is tank irrigation?
Answer
Tank irrigation refers to irrigation in which water stored in artificially
constructed tanks is used for irrigation. Tanks are constructed in areas of
natural depression by building earthen embankments or masonry walls to
collect water.
Question 6
What are the advantages and disadvantages of tank irrigation?
Answer
Advantages of tank irrigation are:
Tank irrigation is cheaper and is prevalent in Deccan plateau where natural
pits and depressions are found.
As the water is collected and used in dry season, it uses the water table of
the surrounding region.
It is difficult to build canals in the Deccan plateau regions.
The tank water is used for domestic purposes in villages.
In the absence of perennial rivers and canals, tanks provide a source of
water during the dry season.
Disadvantages of tank irrigation are:
Since tanks are shallow, large amount of water is wasted through
evaporation.
Tanks are non-perennial and dry up in summer. Considering this and the
large area they occupy, they become costly in comparison to wells and tube
wells.
Tanks use up large areas of land which could be used for agriculture.
Question 7
Where are tanks most widely used and why?
Answer
Tanks are most widely used in peninsular India because natural pits and
depressions are easily available in this area and the rocky base of tanks does
not allow wastage of water due to percolation.
Question 8
Of the two types of wells, which is the best and why?
Answer
Of the two types of wells, tube wells are are best because they can irrigate
larger area and they occupy less area as compared to surface wells. They are
also helpful in drought affected areas.
Question 9
Name two states where tank irrigation and well irrigation is practised.
Answer
Andhra Pradesh and Telangana are two states where tank irrigation and well
irrigation is practised.
Question 10
Name two methods of drawing water from the well.
Answer
Two methods of drawing water from the well are Persian wheel or Rehat and
Moat.
Question 11
Despite big river projects, irrigation through groundwater has still been
growing in popularity. Why is this?
Answer
Despite big river projects, irrigation through groundwater has still been
growing in popularity because of following reasons:
Irrigation projects are still not available in many remote areas of India
whereas ground water is available in most parts.
It is easy and cheap to harvest ground water.
The erratic and variable rainfall has made ground water more popular.
Question 12
For an Indian farmer state two advantages that well irrigation has over canal
irrigation.
Answer
Two advantages that well irrigation has over canal irrigation for an Indian
farmer are:
Well is simplest and cheapest source of irrigation and the poor Indian farmer
can easily afford it.
Well is an independent source of irrigation and can be used as and when the
necessity arises. Canal irrigation, on the other hand, is controlled by other
agencies and cannot be used at will.
Question 13
What is the difference between surface water resource and groundwater
resource? State two advantages of each.
Answer
S. No.Surface water resource Groundwater resource
1. Surface water is available on the surface of earth in the form of rivers,
lakes, ponds and canals. Groundwater is the part of rainwater that seeps
into the ground through the cracks and crevices.
2. Surface water resources are mostly seasonal. Ground water is
available throughout the year and is recharged every monsoon.
3. Can be used directly Requires pumping
4. Usually contaminated Usually fit for drinking
Advantages of Surface water resource:
The surface water is easily available for drinking and irrigation.
The surface water is used for thermoelectric power.
Advantages of Groundwater resource:
The ground water is reliable source of water for drinking.
It is not wasted by evaporation.
Question 14
Name two important canal systems each in Uttar Pradesh and Punjab.
Answer
Canal system in Uttar Pradesh are:
Ganga canal
East Yamuna canal
Canal system in Punjab are:
Sirhind Canal
Makhu Canal
Question 15
Irrigation in India faces many problems. State any two such problems.
Answer
Two problems faced by India regarding irrigation are:
The rainfall is highly uneven and is mostly received in four months. Most of
the rivers are seasonal.
The irrigation projects are still not available in most of the parts of India.
Question 16
Differentiate between inundation canal and perennial canal.
Answer
S. No.Inundation canal Perennial canal
1. Inundation canals are taken out from the rivers without any regulating
systems like weirs and barrages. Perennial canals are taken out from the
rivers with regulating system.
2. Inundation canals are useful only during floods. Perennial canals supply
water throughout the year.
3. They are easy and cheap to built. They are expensive to construct.
Question 17
Give two reasons why inundation canals are being converted to perennial
canals.
Answer
Inundation canals are being converted to perennial canals because:
With Inundation canals, there is uncertainty of water supply. They are useful
only during floods.
Only low-land areas can be irrigated.
Question 18
Give two reasons why tube well irrigation is more important in northern India
than in southern India.
Answer
Tube well irrigation is more important in northern India than in southern India
because:
The land in southern India is rocky while the land in norther India is softer,
which makes it easy and cheap to dig tube wells.
The southern India has other water sources like sea, tanks, ordinary wells
etc.
Question 19
Give two reasons why tank irrigation is more popular in southern India.
Answer
Tank irrigation is more popular in southern India because of following two
reasons:
Most of the area of peninsular India is uneven with many natural depressions
where the tanks can be built.
The Deccan plateau consists of underlying hard rocks which are impervious
or non-porous. These rocks do not allow the water to seep through.
Question 20
Name two states which suffer periodically from droughts. Give a reason for
your answer.
Answer
Two states which suffer periodically from drought are Rajasthan and Gujarat.
Rajasthan and Gujarat receive scanty rainfall because the monsoon winds
have very less moisture left by the time they reach there. Also, the position
of Aravalis direct the winds towards punjab.
Question 21
State the objectives of National Water Policy.
Answer
The objectives of National Water Policy are:
To analyze the existing situation of water
To propose a framework for creation of a system of laws and institutions for
water management
To recycle and treat waste water
Question 22
What is meant by the term Rainwater Harvesting?
Answer
The activity of collecting rainwater directly or recharging it into the ground to
improve groundwater storage in the aquifer is called Rainwater Harvesting.
Question 23
Why is it necessary to conserve water?
Answer
It is necessary to conserve water because
There is uncertainty in rainfall and distribution of water is uneven.
There is over-exploitation and excessive use of water.
Contamination of water due to pollution, use of pesticides and fertilizer.
There is scarcity of water due to large and growing population.
Increasing industrialization and rapid urbanization is exerting pressure on
water resources.
Question 24
How is rainwater harvesting done? Explain.
Answer
Rainwater harvesting is done by
Storing rainwater and later using it in dry season – Harvesting of rainwater is
done by storing it in tanks, ponds and Dams. The stored water is used
directly for irrigation and other domestic purposes.
Recharging of groundwater – It is done by Rooftop rainwater Harvesting
Method. Rainwater can be collected over the rooftops and can be
channelized through small PVC pipes into the underground pits, sump, wells
or borewells.
Question 25
State the advantages of rooftop rainwater harvesting.
Answer
The advantages of rooftop rainwater harvesting are:
Utilization of rainwater to its maximum
Easy and cost effective technique
Recharges groundwater
Avoids wastage of water due to run off
Question 26
Name the state where rainwater harvesting is commonly practised.
Answer
Tamil Nadu and Andhra Pradesh.
Question 27
Give geographical reasons —
River Damodar is called “river of sorrow”.
Irrigation by canals is more suitable in northern India as compared to the
south.
Tank irrigation is used in peninsular India.
Answer
River Damodar was earlier called “river of sorrow” because of its ravaging
floods in the plains of West Bengal which caused heavy losses and
destruction. With the construction of several dams the floods of Damodar
river have been greatly reduced but even now the floods sometimes affect
the lower Damodar Valley.
Canal irrigation is more suitable in northern India as compared to the south
because the northern rivers are perennial and can supply water to canals
throughout the year but the rivers of south India are seasonal and therefore,
canals are of no use in dry season.
The peninsular india has natural depressions which act as natural tanks and
the rocky surface does not allow percolation of water. Therefore, tank
irrigation is used in peninsular India.
Question 28
Answer in one word —
A plastic tube which has small holes through which water keeps on dripping
An ancient irrigation system in North East part of India.
Tube-wells are used extensively in UP and Bihar and are very popular
Answer
Drip irrigation
Bamboo irrigation
Borewell
Question 29
State the advantages and disadvantages of Sprinkler Irrigation.
Answer
Advantages of Sprinkler Irrigation are:
This type of irrigation does not involve any wastage of water by seepage or
evaporation as water is supplied through pipes and not exposed to the sun.
This is the best method for conservation of water.
It is best suited for arid and semi-arid regions.
Water management is easier than surface irrigation system.
Higher application efficiency.
Frequent application is possible.
Does not interfere with the cultivation.
Easy mechanization and automation.
Chemical and fertilizer application can easily be used with sprinkler system.
Disadvantages of Sprinkler Irrigation:
High initial cost.
High operating cost.
Water application efficiency under sprinkler irrigation is strongly affected by
direction of the wind.
Some crops are sensitive and may suffer leaf scorch because of salt
deposited on the leaves after the water evaporates.
High maintenance requirements as constant and meticulous maintenance of
sprinkler system is very important.
Saline water may cause problems.
Water must be free from sand debris and salt.
Question 30
Name the modern methods of Irrigation.
Answer
The modern methods of Irrigation are
Sprinkler Irrigation
Drip Irrigation
Bamboo Irrigation
Question 31
Study the picture and answer the questions that follows :
Study the picture and answer the questions that follows. Name the type of
irrigation. What are the advantages of this type of irrigation? Water
Resources, Geography by Veena Bhargava Goyal Brothers Prakashan ICSE
Class 10.
Name the type of irrigation.
What are the advantages of this type of irrigation?
Answer
Drip Irrigation
Advantages of Drip Irrigation are:
Fertilizer and nutrient loss is minimized due to localized and reduced
leaching.
Water application efficiency is high if managed correctly.
Field levelling is not necessary.
Recycled or non-potable water can easily be used.
Moisture within the root zone can be maintained at field capacity.
Soil erosion is less.
Water distribution is highly uniform.
Labour cost is less.
Variation in supply can be regulated by regulating the valves and drippers.
Fertilization can be included with minimum waste of fertilizers.
Usually operated at low pressure thereby reducing energy costs.
