CLASS 10 NOTES

SOCIAL SCIENCE

RAMAVTAR MEENA
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Approximately 75% of the Earth's surface is covered with water.

About 97.5% of the total volume is ocean water.
2.5% is freshwater, comprising rivers, lakes, groundwater, glaciers, ponds, etc.
70% of freshwater is frozen ice in icebergs and glaciers. Less than 30% of
freshwater is stored as groundwater.
India receives merely 4% of global precipitation.

Water scarcity Water scarcity means shortage of water.

Quantitative reasons for water scarcity
1. Uneven distribution of rainfall: Some regions receive greater rainfall and
some regions come under rain shadow areas and receive less rainfall.
2. Excessive use of groundwater for agricultural purposes.
3. Growing population and consequent greater domestic water demands, growing
urban centres and unequal access to it.
4. Increasing numbers of industries not only exert pressure on existing
freshwater resources but also pollute them.
Qualitative reasons for water scarcity
In some regions where freshwater is available in the form of rivers, lakes, and
ponds, it may be polluted by domestic and industrial wastes, chemicals,
pesticides and fertilizers used in agriculture, thus, making it hazardous for
human use.
NEED FOR WATER CONSERVATION
We have finite water resources, yet our demands are growing exponentially
due to the increasing number of industries, urbanization, and agriculture.
Most of our water resources are polluted, posing severe health hazards and
threatening food security.
To prevent catastrophic consequences such as drought, famine, and epidemics.
To reduce over-exploitation and mismanagement of water resources.
((EE..MM..AA))
To minimise climate changes and uneven distribution of rainfall.

Multipurpose River Projects (MPRP) :

Dams :
A dam is a structure built across a
river or watercourse to hold back
water, creating a reservoir (the
stored water) behind it. JOSH METER?
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Irrigation for agriculture.

Some projects
Bhakra-Nangal project
Electricity generation (hydroelectricity).
on Sutlej-Beas River
Flood control.
basin.
Water supply for domestic and industrial use.
Hirakud project in the
Fish breeding and recreation
Mahanadi basin.

Advantage of (MPRP) Disadvantage of (MPRP)

or Dams or Dams
Irrigation Multipurpose projects can induce
Hydroelectricity for our industries earthquakes.
and homes. It displaces the local people of the
place where it is constructed.
Water supply for drinking
It can cause water-borne diseases
Flood control Unsuccessful in controlling floods
Recreational facilities It affects the river's natural flow
Inland navigation Submerge the existing vegetation
Pisciculture (fish breeding) and soil.
Destroys the habitats for the
Soil conservation
river‘s aquatic life.

Rainwater Harvesting
The harvesting of rainwater simply involves the collecting of water from the
surface on which rainfalls and subsequently saving this water for later use.
A water harvesting system was a viable alternative, both socio-economically
and environmentally.

MAIN OBJECTIVE 🤔
To meet the increasing demands of water.
Support growing demand for water for irrigation and domestic use.
Promoting sustainable water management practice
To reduce groundwater pollution and improve the quality of groundwater.
Conserving and recharging groundwater.

Methods of Rainwater harvesting:

(i) Guls and Kuls:

In mountainous areas of the western Himalayas, rainwater is collected and

saved for agriculture.
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(ii) Tankas (iii) Khadins and Johads

In arid and semi-arid areas of Rajasthan In Jaisalmer & Rajasthan,
[Bikaner, Phalodhi] Underground tanks agricultural fields were converted
for storing rainwater harvested from into rain-fed storage structures.
rooftops for drinking purpose
(iv) Bamboo drip irrigation
system in Meghalaya
A system of tapping streams and spring
water using bamboo pipes has been used for
over 200 years to transport water.

Rooftop Rainwater Harvesting:

In rooftop harvesting, the roof acts as the catchment, and the rainwater is
collected from the roof of the house/building. It can either be stored in a
tank or diverted to an artificial recharge system.
Rainwater from rooftops is collected using pipes.
Pipes are connected to underground tanks.
Rocks and sand in the tanks filter the rainwater.
Clean water is then available for drinking purposes.
This eco-friendly system ensures a steady supply of clean drinking water, even
during water scarcity periods, making it an ideal solution for sustainable living."

Gendathur model
*Location:* Gendathur is a backward village in Mysuru, Karnataka
*Achievement:* 200+ households with rooftop rainwater harvesting systems,
collecting over 1.5 million litres of water annually.
*Impacts:*
Reduced dependence on external water sources by 70%.
Conserved water for future generations, ensuring a sustainable future.
Replicable model for other villages, inspiring a wave of community-led
sustainability initiatives.
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Major dams in India:

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Top 7 Questions
Q1. Multipurpose projects are temples of modern India. Justify?

Ans: Jawaharlal Nehru proclaimed dams as the ‘temples of modern India’ because
of the following reasons:

(i) Dams would integrate the development of agriculture and the rural economy
with rapid industrialization and growth of the urban economy.

(ii) Multi-purpose projects were thought of as the vehicle that would lead the
nation to development and progress, overcoming the handicap of its colonial past.

Q2. Explain any three reasons for water scarcity in India?

Ans. Water scarcity limits access to safe water for drinking and for practising
basic hygiene at home, in schools and in healthcare facilities.

The following are the reasons for water scarcity in India ;

i) Uneven distribution of rainfall Some regions receive greater rainfall and some
regions come under rain shadow areas and receive less rainfall. Ex: Marathwada
region of Maharashtra.
ii) Over-exploitation of groundwater in Agriculture accounts for 80% of India's
groundwater usage.
iii) Industrial Demands: Industries like textiles, paper, and steel require significant
water supplies, further straining resources.
iv) Growing population and consequent greater domestic water demands, growing
urban centres and unequal access to it.

Q3. On which river is the Sardar Sarovar Dam constructed?

Ans: Sardar Sarovar Dam is constructed on the River Narmada.

Q4. How have intensive industrialisation and urbanisation put great

pressure on existing freshwater resources in India?
Ans:
"The last few decades have seen immense pressure on freshwater resources
due to rapid urbanization and industrialization.
Multinational companies have increased water consumption, while hydroelectric
power production for industrial use has not only threatened the availability of
freshwater resources but also contributed to water quality degradation.
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The growing number of urban centres has led to a surge in demand, driven by
modern lifestyles and domestic needs.
In housing colonies, water resources are being overexploited to meet the
needs of the population, resulting in groundwater depletion.

Q5. Explain the qualitative aspects of water scarcity.

Ans: Water scarcity refers to the lack of sufficient available water resources to
meet the demands of water usage within a region. This concept isn't just about the
quantity of water available, but also encompasses various qualitative aspects:

i) Water quality- Even if water is available in sufficient quantities, it may be unfit

for use due to contamination by pollutants, chemicals, or pathogens.

ii) Accessibility- Water may be abundant in one area but scarce in another due to
natural distribution. This disparity creates regional inequalities in water availability.

iii) Economic Scarcity: Even where water is physically available, it may be

economically inaccessible to certain populations due to the high cost of extraction,
treatment, or distribution.

Q6. Describe the working of the rooftop rainwater harvesting technique.

Ans. "The rooftop rainwater harvesting technique works as follows:
1. Collection: Rainwater falling on the roof is collected through a network of PVC
pipes.
2. Filtration: The collected rainwater is filtered using a combination of sand and
bricks to remove impurities.
3. Storage: The filtered water is then stored in a sump for immediate use.
4. Excess water management: Excess water from the sump is transferred to a well,
which recharges the groundwater aquifer.
5. Additional water supply: In case of further water requirements, water can be
drawn from the well.
This technique ensures a steady supply of clean water, reduces dependence on
municipal water, and helps recharge groundwater levels."

Q7. Which of the following remote backward villages in Mysore Karnataka

installed household rooftop rainwater?
a. Gendathur
b. Vanathalipuram
c. Chilkunda
d. Kallahalli

Ans: (a) Gendathur