I. Choose the correct option:
- What is an aquifer?
(c) An underground stream saturated with water that is transmitted readily on to the surface. - Which of the following does
not conserve water?
(b) Using only bottled drinking water - Assertion (A): Many states
have recorded a sharp fall in the groundwater levels, ranging from 70 to
80 per cent.
Reason (R): With the increase in population the demand for water has risen.
(a) Both A and R are true and R is the correct explanation of A. - Which of the following is a
cause for the decline in groundwater levels?
(c) Loss of vegetative cover - Sprinkler irrigation is also
known as
(b) Overhead irrigation - Tanks form the main source
of irrigation in
(b) the Deccan Plateau - Assertion (A): Cherrapunji,
which receives about 11,000 mm of rainfall annually, suffers from acute
shortage of drinking water.
Reason (R): Most of the rain falling on the surface tends to flow away rapidly, leaving very little for the recharge of groundwater.
(a) Both A and R are true and R is the correct explanation of A. - Which is not a conventional
means of irrigation?
(a) Furrow irrigation - Rahul is constructing a
house in Mathura. Of the following methods select those that he can use to
ensure rainwater harvesting:
(i) A garden
(ii) Porous tiles in his driveway
(iii) Rooftop rainwater harvesting
(iv) Borewell
(a) (i), (ii), (iii), (iv) - Assertion (A): Runoff from
only paved surfaces is used for storing rainwater.
Reason (R): It is relatively free of bacteriological contamination.
(a) Both A and R are true and R is the correct explanation of A. - Most of the canals in India
belong to which category?
(a) Perennial canals - Which of the following least
irrigated state of India is solely dependent on canals?
(b) Mizoram - Assertion (A): For farmers
rainfall is still the most important source of water.
Reason (R): Irrigation canals and tanks have been constructed by rulers since ancient times.
(b) Both A and R are true but R does not explain A. - You have to maintain one
public park in your colony. Which method of irrigation would you prefer?
(d) Sprinkler irrigation
II. Answer the following questions:
Q.1 (a)
What do you understand by the term 'water resource'?
Water resource refers to the entire range of natural waters occurring on the
earth that are of potential use to living beings. This includes waters from
oceans, rivers, lakes, groundwater, glaciers, and snowfields.
(b) Give
two points of difference between 'surface water' and 'groundwater'.
|
Aspect |
Surface Water |
Groundwater |
|
Source |
Water
on the surface in streams, rivers, lakes, ponds |
Water
stored beneath the earth's surface, in soil and rock crevices |
|
Availability |
Easily
accessible and visible |
Requires
drilling or digging to access |
|
Usage |
Used
directly for irrigation, drinking, industry |
Mostly
used by wells, tubewells for irrigation and drinking |
(c) Give
a geographical reason for each of the following:
(i) Need
to adopt different means of irrigation:
Because rainfall in India is uneven in distribution and erratic in timing,
different regions require different irrigation methods based on soil types,
water availability, and terrain.
(ii) Need
for conserving water:
Water resources are finite and are being depleted rapidly due to population
growth, overuse in agriculture, and pollution.
(iii) Man
is responsible for water crisis:
Overexploitation of groundwater, pollution of water bodies, and deforestation
caused by human activities have led to declining water availability.
(d)
Rajasthan faces water scarcity, particularly in dry areas. The government has
initiated water harvesting projects to enhance water availability.
(i) What
is meant by water harvesting?
Water harvesting is the process of collecting and storing rainwater locally for
reuse or for recharging groundwater.
(ii) State
the objectives of water harvesting schemes:
- To meet increasing water
demand
- Reduce surface runoff and
avoid flooding
- Raise groundwater levels
- Prevent soil erosion
- Improve water quality
- Supplement water supply
during droughts and summer
Q.2 (a)
What is meant by the term irrigation?
Irrigation is the artificial application of water to plants or soil to assist
in crop growth.
(b) What
is meant by the term 'water scarcity'? What has caused this scarcity in India?
Water scarcity is when the demand for water exceeds the available supply. In
India, it is caused by uneven rainfall, population growth, overuse of
groundwater, and pollution.
(c) Give
a geographical reason for each of the following:
(i) Inundation
canals are being converted to perennial canals:
Because inundation canals are only functional during floods, converting them to
perennial canals with dams provides a year-round water supply.
(ii) Tank
irrigation is preferred over other means of irrigation in Peninsular India:
The region has many streams that dry up after the rainy season and hard rock
surfaces that prevent groundwater recharge, making tanks ideal for storing rainwater.
(iii) Groundwater
reserves are depleting at a fast rate:
Due to overextraction for agriculture, industry, and domestic use without
adequate recharge.
(d) (i)
What is meant by traditional or conventional methods of irrigation?
These are older methods involving wells, tanks, and inundation canals to
provide water to crops.
(ii) Name
any two conventional methods of irrigation:
- Well irrigation
- Tank irrigation
Q.3 (a)
State any two drawbacks of conventional methods of irrigation:
- Large amounts of water are
wasted due to improper distribution.
- They cause waterlogging and
salinity in the soil.
(b) Give
two advantages and two disadvantages of well irrigation:
Advantages:
- Low cost and affordable to
poor farmers
- Oxen or pumps can be used to
lift water easily
Disadvantages:
- Wells dry up due to overuse
- Not suitable in rocky or
hilly areas
(c) Give
a geographical reason for each of the following:
(i) Well
irrigation is confined mainly to the alluvial plains:
Because the soil is soft and water table is relatively shallow, making wells
easy to dig.
(ii) In
Tamil Nadu, nearly one-third of the net irrigated area is under canal
irrigation:
Because Tamil Nadu has a developed canal system utilizing river water and
rainfall is seasonal.
(iii) Drip
irrigation reduces loss of water through evaporation:
Since water is delivered directly to the roots in small amounts, minimizing
surface evaporation.
(d) (i)
Name any two states where well irrigation is practised:
- Punjab
- Andhra Pradesh
(ii) Give
one advantage and one disadvantage of tubewell irrigation:
Advantage:
- Provides a perennial source
of clean water.
Disadvantage:
- Expensive due to electricity
or fuel costs.
Q.4 (a)
Name the two types of canals. Name two states where perennial canals are widely
used:
Types of
canals:
- Inundation canals
- Perennial canals
States
with perennial canals:
- Punjab
- Uttar Pradesh
(b) How
are the fields irrigated using the Persian wheel method?
A vertical wheel with buckets is turned by animals; buckets lift water from
wells and discharge into a trough leading to fields.
(c) Give
a geographical reason for each of the following:
(i) Canals
make the soil infertile:
Due to waterlogging, salts rise to the surface causing soil salinity.
(ii) Tubewell
irrigation is quite expensive:
Because it requires power or diesel to run pumps continuously.
(iii) Excessive
accumulation of salts make the soils unsuitable for cultivation:
Poor drainage and over-irrigation cause salts to build up on soil surfaces.
(d) (i)
What conditions favour the development of canal irrigation in Punjab?
Availability of perennial rivers, level land, fertile soil, and a flat terrain.
(ii) State
two disadvantages of canal irrigation:
- Waterlogging and salinity of
soil
- Loss of cultivable land due
to canals
Q.5 (a)
Briefly explain why groundwater levels are dropping rapidly in India:
Overextraction for irrigation and domestic use, reduced recharge due to
deforestation, and increasing population pressure.
(b) How
can groundwater be recharged? Name a method to recharge groundwater:
By capturing rainwater and allowing it to seep into the ground. One method is
recharge pits.
(c) Give
a geographical reason for each of the following:
(i) Many
farmers in India still use wells:
Because wells are affordable and accessible in many regions.
(ii) There
is very little recharge of groundwater:
Due to concrete surfaces and deforestation reducing infiltration.
(iii) Tubewells
are important in Punjab:
Punjab has a high water table and abundant agriculture requiring perennial irrigation.
(d) (i)
What is watershed management?
It is the management and conservation of soil and water resources within a
geographical area draining to a common point.
(ii) How
is it beneficial for farmers in the long run?
It improves water availability, reduces soil erosion, enhances groundwater
recharge, and sustains crop production.
Q.6 (a)
What is 'drip irrigation'? How is it useful?
Drip irrigation delivers water directly to the roots through perforated pipes,
reducing evaporation and conserving water.
(b)
Explain briefly the need to conserve water:
To ensure sustainable supply for drinking, agriculture, and industry amidst
growing demand and declining sources.
(c) Give
a geographical reason for each of the following:
(i) Modern
means of irrigation are gaining popularity:
They use water more efficiently and suit dry and water-scarce regions.
(ii) Sprinkler
irrigation helps in conserving water:
It applies water uniformly and reduces surface runoff or seepage losses.
(iii) Spray
irrigation is quite expensive:
Requires costly equipment and maintenance.
(d) What
is meant by furrow irrigation? What is its advantage?
Water flows through narrow channels between crop rows. It is useful where water
is easily available and saves water compared to flooding.
Q.7 (a)
Picture 7(a) shows drip irrigation in a field. List its advantages:
- Saves water by limiting
evaporation
- Delivers water directly to
plants
- Reduces weed growth
- Increases crop yield with
less water
(b)
Picture 7(b) is Agrasen ki Baoli (New Delhi)... Write a short note on any
traditional irrigation method:
Step wells or Baolis are ancient structures dug deep into the ground with steps
to access water. They stored water during droughts and were community sources.
(c) Give
a geographical reason for each of the following:
(i) Loss
of water due to evaporation is highest in tanks:
Because of their shallow and wide surface area exposed to sun.
(ii) Many
cities have banned construction of tubewells:
Due to overextraction causing falling water tables and land subsidence.
(iii) Rabi
crops are grown in areas with irrigation facilities:
Because these crops need water during winter when rainfall is scarce.
(d) Given
a choice which modern method of irrigation would you use to irrigate your farm?
Give reasons to support your answer:
I would choose drip irrigation because it conserves water by delivering
it directly to roots, reduces evaporation, and increases crop productivity.
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