NCERT Geography Class 9 Chapter 3 | Role Of Rivers In The Economy & River Pollution Notes & PDF

Topic covered: Role Of Rivers In The Economy & River Pollution and MCQs Questions: Drainage (All single detail notes are exam-oriented).

We have discussed in-depth and exam-oriented pointers that can be asked in the board exam of class 9th about the “Role Of Rivers In The Economy & River Pollution” from the NCERT Geography notes for class 9th chapter 3 “Drainage“.

Download the NCERT Geography for Class 9th Chapter 3 Drainage Notes PDF

NCERT Geography for Class 9th Chapter 3 – Drainage Notes & MCQ’s Question-Answer

The chapter Drainage in Class 9 Geography explains India’s river systems and their role in shaping our land and life. It covers the Himalayan rivers like the Ganga, Brahmaputra, and Indus, as well as the Peninsular rivers such as the Godavari, Krishna, and Mahanadi. These notes highlight key features like river basins, lakes, and the importance of rivers for agriculture, transport, and economy. The PDF is structured for quick learning with clear summaries, maps, and exam-oriented points. Download it to revise NCERT Geography Class 9 Chapter 3 Drainage easily and strengthen your preparation before tests and exams.

Role Of Rivers In The Economy

1. Historical Importance:

• Rivers have been of fundamental importance throughout human history.
• Water from rivers is a basic natural resource essential for human survival and activities.
• Riverbanks attracted early settlers, which later developed into big cities.

2. Role in Agriculture & Livelihood:

• Rivers provide water for irrigation – crucial in India where agriculture is the main livelihood for most people.
• Fertile alluvial soil deposited by rivers boosts agricultural productivity.

3. Role in Economy & Development:

• Rivers support hydro-power generation, which helps in industrial and domestic use.
• They serve as inland waterways/navigation routes, facilitating transport and trade.
• Many Indian cities are river-based, linking urban growth with river systems.

4. Exam-Oriented Examples/Tasks:

• Students may be asked to list cities in their state located on riverbanks (e.g., Delhi on Yamuna, Kolkata on Hooghly, Patna on Ganga).

River Pollution

1. Growing Demand & Impact on Rivers:

• Domestic, municipal, industrial and agricultural demand for river water is increasing.
• This leads to reduction in river volume because more water is drained out.

2. Sources of River Pollution:

• Untreated sewage is released into rivers.
• Industrial effluents (toxic waste from factories) are also discharged.
• Both degrade the quality of water and harm aquatic life.

3. Effect on Rivers:

• Polluted rivers lose their self-cleansing capacity (natural ability to purify water).
• Example:
  a. With adequate streamflow, Ganga water can dilute and assimilate pollution within 20 km of large cities.
  b. But due to urbanisation and industrialisation, this natural process is failing.

4. Rising Pollution & Government Measures:

• Pollution levels in many rivers are rising continuously.
• Concern over this led to the launch of various action plans to clean rivers (e.g., Ganga Action Plan, Namami Gange Mission).

5. Health Concerns:

• Polluted river water can cause serious health issues such as water-borne diseases.
• Lack of freshwater availability poses a danger to human survival.

Next & Previous Topics of NCERT/CBSE Geography Class 9 Chapter 3: Drainage

MCQs on NCERT Geography Class 9 Chapter 3 Topic – Role Of Rivers In The Economy & River Pollution

Here are the top exam-oriented MCQ-type questions on “Role Of Rivers In The Economy & River Pollution” that you should prepare for your CBSE or state board exams:

Question 1. Rivers have been of fundamental importance throughout:

a) Modern period
b) Medieval period
c) Human history
d) Industrial age

Answer: c) Human history

Question 2. Which of the following is a basic natural resource provided by rivers?

a) Minerals
b) Water
c) Soil
d) Coal

Answer: b) Water

Question 3. Riverbanks have attracted settlers since:

a) Industrial Revolution
b) Ancient times
c) Modern times
d) Medieval times

Answer: b) Ancient times

Question 4. Which of the following is NOT a role of rivers in the economy?

a) Irrigation
b) Navigation
c) Hydro-power generation
d) Oil drilling

Answer: d) Oil drilling

Question 5. Why are rivers particularly important for India?

a) Because India is an industrial country
b) Because India is an agricultural country
c) Because India is a desert country
d) Because India has no groundwater

Answer: b) Because India is an agricultural country

Question 6. The quality of river water is affected by:

a) Domestic demand
b) Municipal demand
c) Industrial demand
d) All of the above

Answer: d) All of the above

Question 7. Which factor reduces the volume of rivers?

a) Heavy rainfall
b) Excessive withdrawal of water
c) Melting glaciers
d) Deforestation

Answer: b) Excessive withdrawal of water

Question 8. Which of the following is the major cause of river pollution?

a) Forest cover
b) Treated sewage
c) Untreated sewage and industrial effluents
d) Rainwater

Answer: c) Untreated sewage and industrial effluents

Question 9. What does river pollution affect the most?

a) Speed of flow
b) Self-cleansing capacity
c) Depth of river
d) Fertility of soil

Answer: b) Self-cleansing capacity

Question 10. Given adequate streamflow, the Ganga water can dilute pollution loads within:

a) 10 km of large cities
b) 15 km of large cities
c) 20 km of large cities
d) 50 km of large cities

Answer: c) 20 km of large cities

Question 11. Why is Ganga unable to dilute pollution as effectively now?

a) Because glaciers have melted
b) Because of increasing urbanisation and industrialisation
c) Because the river has dried up
d) Because of over-fishing

Answer: b) Because of increasing urbanisation and industrialisation

Question 12. Which action has been taken to reduce river pollution?

a) Deforestation programmes
b) Desert development plans
c) River action plans
d) Industrialisation plans

Answer: c) River action plans

Question 13. Pollution in rivers directly affects:

a) Tourism
b) Only agriculture
c) Human health
d) Only aquatic animals

Answer: c) Human health

Question 14. What does untreated sewage and industrial effluents cause?

a) Purification of water
b) Pollution of rivers
c) Increase in self-cleansing capacity
d) Flood control

Answer: b) Pollution of rivers