NCERT Solutions for Class 9 Geography Chapter 3 – Drainage

This chapter is about drainage which describes the river system of an area with its  tributaries, river flow, and distinct characteristics. Small streams which flow from different directions and form a larger water body which drains into a lake, a sea or an ocean. An area drained by a single river system is called a  drainage basin.  Often we find hills, mountains or upland features separating two drainage basins, and this elevated feature is called the water divide. 

This Chapter has been effectively covered by Extramarks using  pictures,  maps, comprehensive answers  etc., in an easy to understand language. The subject matter experts have ensured a concise syllabus per NCERT directions, keeping the CBSE examination in mind, supplemented by the Class 9 Geography Chapter 3 question answer. 

The subject of Social Sciences is vital in every walk of life, and students can perform well in future competitive examinations like UPSC only if their fundamental understanding  is strong enough.

Key Topics Covered in NCERT Solutions for Class 9 Geography Chapter 3

The NCERT Solutions for Class 9 Geography Chapter 3 covers the following topics:

Introduction

The drainage in India originates from two main physical features, viz the Himalayas and the peninsula. These river systems have unique characteristics and flow patterns, as explained  in the NCERT Solutions for Class 9 Geography Chapter 3. 

The Indian rivers are divided into two major groups: The Himalayan rivers and the Peninsular rivers.The rivers emanating from the Himalayas receive water from both the rainfall and the melting ice, due to which they never dry up. They are also known as Perennial rivers. The Indus and the Brahmaputra are two such perennial rivers. These rivers are very swift and often cut through the mountain rocks forming gorges. They cause deep erosion and carry significant silt and sand toward the sea. The Himalayan rivers leave behind many depositional features like meanders and oxbow lakes  in the middle courses and deltas in the lower courses. 

The Peninsular rivers, on the other hand, their flow solely depend on rainfall and they are seasonal.  . Large rivers lose their flow during the dry season. The Peninsular rivers are slow-moving, shallower, and shorter courses than their Himalayan counterparts. Most of the peninsular rivers originate in the Western Ghats and flow towards the Bay of Bengal in  the east. 

The Himalayan Rivers

A river along with its tributaries is called a river system. In this Chapter, we learn about India's three long river systems, viz the Indus, the Ganga, and the Brahmaputra.

The river Indus originates in Tibet, near lake Mansarovar, and enters India via Ladakh. Many tributaries like the Zanskar, the Nubra, the Shyok, and the Hunza join the Kashmir region. The Indus river system leaves some impressive gorges and valleys in its wake, attracting tourists from  far and wide. It flows further towards Pakistan, via east Karachi, to eventually join the Arabian Sea. The Indus is 2,900 km long, and it’s one of the longest rivers of the world.  A third of the Indian basin is located in India (Ladakh, Jammu and Kashmir, Punjab and Himachal Pradesh) and two thirds in Pakistan. 

The Ganga riverine is a little shorter at 2,500 km in length and flows towards the Bay of Bengal.The headwaters of the river Ganga are called the ‘Bhagirathi’ and are fed by Gangotri glacier in the Himalayas. At Devprayag, it is joined by the Alaknanda river. In Haridwar it emerges from the mountains onto the plains.  From the water divide between the Indus and the Ganga, located at Ambala, the gentle plains stretch out for about 1,800 km till the Sunderban delta. Owing to the very gentle elevation gradient, we find many meanders in the course of the Ganga. 

The Gangotri Glacier gives rise to 'Bhagirathi' or the headwaters of the river Ganga. It reaches the plains at Haridwar and is joined by many tributaries from the Himalayas. One of them is the river Yamuna, which has its origin at Yamunotri Glacier, joining the Ganga at Allahabad. Apart from enriching the soil, some of its tributaries end up causing floods in the northern plains. After touching West Bengal, the Ganga bifurcates, with the mainstream flowing towards Bangladesh, where the Brahmaputra joins it, forming the Sundarban Delta. In India, only a tributary of the Ganga, namely the Bhagirathi-Hooghly, flows south into the deltaic plains to the Bay of Bengal.

Like the Indus, the Brahmaputra also originates in Tibet, from the east of Mansarovar lake, and is slightly longer than the Indus. Flowing parallel to the Himalayas eastwards, it changes course at Namcha Barwa ,it takes a ‘U’ turn to enter Arunachal Pradesh. In Tibet, the river carries a small volume of water and silt , however in India, it carries a high  volume of water and silt deposit in the Brahmaputra rapidly increases after entering the heavy rainfall , giving a braided pattern in the entire length in Assam. and forms many riverine islands. . 

Unlike the north Indian rivers  the Brahmaputra  carries  heavy silt that makes the river bed rise, creating new channels  and causing floods in the rainy season in Assam and Bangladesh.

Rivers in the Peninsula region

The Western Ghats, running from north to south, act as the water divide in the Indian Peninsula. All the major rivers like the Mahanadi, the Krishna, the Godavari, and the Kaveri flow eastwards to the Bay of Bengal, making deltas at their mouths. The few rivers (the Narmada and the Tapi) that flow westwards, making estuaries, are short, with smaller drainage basins created towards the Arabian Sea. The rivers flowing westwards often create rift valleys and deep gorges, which are very attractive to tourists. Noteworthy among them are the ones created by the river Narmada, viz the 'Marble rocks' and the 'Dhuandhar falls'. 

  1. Godavari Basin:

Amongst the rivers from the Western Ghats flowing eastwards, the Godavari is the longest river running for 1,500 km, eventually draining into the Bay of Bengal and forming the largest river basin in the peninsula. 

The Godavari is also called Dakshin Ganga, owing to its length. The Krishna (1,400 km), the Mahanadi (860 km), and the Kaveri (760 km) are the other long rivers draining into the Bay of Bengal and forming relatively large drainage basins. 

  1. Narmada Basin:

Rising in the Amarkantak hills of Madhya Pradesh state, Narmada flows through a deep gorge near Jabalpur. The river covers parts of two states Madhya Pradesh and Gujarat.

  1. Krishna Basin:

The Krishna river is approximately 1,400 km long and it rises from a spring in the Mahadev range near Mahabaleshwar and the river falls into the Bay of Bengal. The river flows through the states oof Maharashtra, Karnataka and Andhra Pradesh.

  1. Tapi Basin:

The river originates from the Satpura ranges located in Betul district of Madhya Pradesh. It flows through a basin that covers Maharashtra, Gujarat and Madhya Pradesh. The entire Tapi basin is divided into three sub-basins - upper, middle and lower and also in hilly regions and in plain areas.

  1. 5. Kaveri Basin:

Kaveri river originates in the Brahmagiri range of the Western Ghats. Its length is around 760 km and the river reaches the Bay of Bengal at Kaveripatnam. The river basin is shared across the status of Karnataka, Kerala, Tamil Nadu and Puducherry.

  1. 6. Mahanadi Basin:

Mahanadi river is around 860 km long and it originates from the highlands of Chhattisgarh. It reaches the Bay of Bengal after travelling from Chhattisgarh, Maharashtra, Jharkhand, and Odisha. 

Lakes of India

India is gifted with many lakes, each with different sizes and features. Some lakes are formed by glaciers and ice sheets, while others are formed  during the rainy season like the lakes  in the basins of semi-arid regions, some others are formed due to glaciers and ice sheets, and some are due to human activity or river or wind action. Most lakes, however, are perennial and need not depend on rainfall or anything else. 

When a meandering river approaches floodplains, portions of it get detached and form u-shaped oxbow lakes. Lagoons in the coastal region get formed by spits and bars. Some of the seasonal inland drainage lakes are high in salt content and can be used to extract salt, for example, the Sambhar Lake in Rajasthan. Otherwise, the lakes are generally freshwater since most originate from the Himalayan region. The Wular lake in Jammu and Kashmir is the largest fresh water lake in India. The Dal lake, Bhimtal, Loktak , Nainital are important freshwater lakes in India. The damming of rivers  to generate hydropower has resulted in the formation of lakes such as Guru Gobind Sagar - Bhakra Nangal Project.

Development through Rivers and Lakes

The lakes and rivers play an essential role in   economic development. Besides enhancing the aesthetics  and offering boating, water sports and recreational activities, lakes help regulate the river flow because it prevents  flooding during heavy rainfall and maintains  the even flow of the river during the dry season. Lakes balance the aquatic ecosystem, keep the climate moderate, and help harness hydel power. 

On the other hand,  rivers are the primary source of hydel power. Their prominent role in India is in agriculture, industries and maritime activities. Water being a basic necessity, human settlements most often revolve around rivers particularly in a country like India which is dependent on agriculture.  

Pollution in rivers

The overexploitation of rivers in our country is a matter of grave concern. The chapter brings out some facts like the depletion of river volume due to increasing demand for domestic, industrial, agricultural and municipal use. The rivers are the central dump yards for waste, industrial effluents, and untreated sewage. The inherent self-cleaning quality of the rivers takes a big hit with this kind of harmful overload. As a result, the overall quality of the river water degrades, creating health problems for humans, fishes, animals and birds. The Indian government has launched many programmes to preserve the quality and quantity of our rivers.   

NCERT Solutions for Class 9 Geography Chapter 3: Exercises &  Solutions

Its Extramarks endeavour to ensure each student scores high in their Examination. The NCERT Solutions for Class 9 Geography Chapter 3 by Extramarks come with a total package of revision notes, sample question papers,  projects and map-related exercises, making Social Sciences more interesting  and easy to understand. 

Students can access NCERT Solutions for Class 9 Social Science Geography Chapter 3 from the link  given below: :

Extramarks also provide the NCERT Solutions for other classes, such as:

NCERT Solutions Class 12

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NCERT Solutions Class 3

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Key Features of NCERT Solutions for Class 9 Geography Chapter 3

The essential features of the NCERT Solutions for Class 9 Geography Chapter 3 are:

  • This chapter describes India's drainage or river system, its origin,  characteristics, relief features formed along its  path, and the drainage basin. 
  • The northern Himalayas and other elevated physical features in India are the main origins of the river system. 
  • Apart from creating new and modifying existing physiographic divisions , the river system also influences our country's  vegetation, soil fertility, forests, occupation, settlements, and climatic systems.
  • Lakes are a subset of rivers and are as helpful as rivers in maintaining a healthy environment and building  the economy of India.
  • The chapter also discusses how development and industrialisation lead to water pollution and environmental degradation. 

Q.1 Choose the right answer from the four alternatives given below.
(i) In which of the following states is the Wular lake located?
(a) Rajasthan
(b) Uttar Pradesh
(c) Punjab
(d) Jammu and Kashmir

(ii) The river Narmada has its source at
(a) Satpura
(b) Brahmagiri
(c) Amarkantak
(d) Slopes of the Western Ghats

(iii) Which one of the following lakes is a saltwater lake?
(a) Sambhar
(b) Dal
(c) Wular
(d) Gobind Sagar

(iv) Which one of the following is the longest river of the Peninsular India?
(a) Narmada
(b) Krishna
(c) Godavari
(d) Mahanadi

(v) Which one amongst the following rivers flows through a rift valley?
(a) Mahanadi
(b) Tungabhadra
(c) Krishna
(d) Tapi

Ans.

(i) (d) Jammu and Kashmir
(ii) (c) Amarkantak
(iii) (a) Sambhar
(iv) (c) Godavari
(v) (d) Tapi

Q.2 Answer the following questions briefly.

(i) What is meant by a water divide? Give an example.
(ii) Which is the largest river basin in India?
(iii) Where do the rivers Indus and Ganga have their origin?
(iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
(v) Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
(vi) Which two Peninsular rivers flow through trough?
(vii) State some economic benefits of rivers and lakes.

Ans.

(i) An elevated area such as a mountain or an upland that separates two drainage basins is known as a water divide. The Western Ghats is the best example of the water divide.
(ii) The Ganga river basin is the largest river basin in India.
(iii) The Indus River has its origin in Tibet near the Mansarovar Lake while the Ganga River has its origin in Gangotri Glacier in Uttarakhand.
(iv) The two headstreams of the Ganga are the Bhagirathi and Alaknanda. They meet at Devaprayag in Uttarakhand to form the Ganga.
(v) The Brahmaputra River in Tibet receives a very little volume of water in so it carries little silt there. However, once it enters India, Brahmaputra is fed by heavy rains, and it carries a lot of water and silt.
(vi) The two rivers that flow through troughs are the Narmada and the Tapi. These are the west-flowing rivers, which form estuaries while entering the Arabian Sea.
(vii) Some economic benefits of rivers and lakes are:
a. Lakes and rivers are used to produce hydroelectricity.
b. They are useful for navigation.
c. They are beneficial for fisheries.
d. They are useful for irrigation.
e. Many ancient human settlements are established near the lakes and rivers. For example, Bhopal in India is a lake city while Indo-Gangetic Plains are known for their ancient civilization.
f. They are tourist destinations.

Q.3 Below are given the names of a few lakes of India. Group them under two categories– natural and created by human beings.

(a) Wular
(b) Dal
(c) Nainital
(d) Bhimtal
(e) Gobind Sagar
(f) Loktak
(g) Barapani
(h) Chilika
(i) Sambhar
(j) Rana Pratap Sagar
(k) Nizam Sagar
(l) Pulicat
(m) Nagarjuna Sagar
(n) Hirakund

Ans. Natural lakes: (a) Wular (b) Dal (c) Nainital (d) Bhimtal (f) Loktak (g) Barapani (h) Chilka (i) Sambhar (l) Pulicat.

Man-made lakes: (e) Gobind Sagar (j) Rana Partap Sagar (l) Nizam Sagar (n) Nagarjuna Sagar (n) Hira Kund.

Q.4 Discuss the significant difference between the Himalayan and the Peninsular Rivers.

Ans.

The Himalayan Rivers The Peninsular Rivers
They are snowfed. They are rainfed.
They rise from the Himalayas. They originate in the Western Ghats.
They are long distant rivers. They are short distant rivers.
They are perennial rivers. They are seasonal rivers.
They have large basins. They have small basins.
For example: Ganga, Yamuna, Indus, Brahamputra, etc. For example: Krishna, Kaveri, Godavari, Mahanadi, etc.

Q.5 Compare the east flowing and the west flowing rivers of the Peninsular plateau.

Ans.

The East Flowing Peninsular Rivers The West Flowing Peninsular Rivers
They drain into the Bay of Bengal. They drain into the Arabian Sea.
They cover a longer distance. They cover a shorter distance.
They form deltas. They form estuaries.
For example, the Kaveri, the Godavari, etc. For example, the Narmada and the Tapi.

Q.6 Why are rivers important for the country’s economy?

Ans. The rivers are important in country’s economy because of the following reasons:

  • Most of the ancient human civilizations originated, flourished and developed in the river valleys.
  • They carry water containing sediments and minerals, which are very useful for agriculture.
  • They provide water for various human activities like domestic, agricultural, and industrial purposes.
  • Rivers provide cheap and efficient inland transport for trade and commerce.
  • They are used in generating hydroelectricity.
  • They also provide water to reservoirs, which are used for fishing and recreational activities.

Q.7 On an outline map of India mark and label the following rivers: Ganga, Satluj, Damodar, Krishna, Narmada, Tapi, Mahanadi, and Brahmaputra.

Ans.

Q.8 On an outline map of India mark and label the following lakes: Chilika, Sambhar, Wular, Pulicat, Kolleru.

Ans.

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FAQs (Frequently Asked Questions)
1. What are the main takeaways from the NCERT Solutions for Class 9 Geography Chapter 3?

Rivers form one of the crucial features of India’s Geography, as specified in the NCERT Solutions for Class 9 Geography Chapter 3. The primary occupation of India was  farming,  with heavy dependency on rivers for irrigation. They also help in industrialisation, tourism, power generation, and the overall development of India’s economy. So we must preserve the river system and protect it from all kinds of pollution.

2. How have Extramarks dealt with the NCERT Solutions for Class 9 Geography Chapter 3?

Extramarks has meticulously prepared the NCERT Solutions syllabus for Class 9 Geography Chapter 3, ensuring each topic is described adequately. There is the regular usage of illustrations, maps, pictures etc., apart from case studies, practical exercises and even crossword puzzles  or gamified content to revise the topics  and strengthen the conceptual knowledge. 

3. Which questions are crucial from Chapter 3 for the CBSE examination?

Extramarks suggest revising the following questions from the Chapter for Class 9 Geography Chapter 3:

  • What are the differences  between Himalayan rivers and Peninsular rivers?
  • How are lakes formed, and why  are they essential to India’s economy?
  • What are the initiatives taken by our government to preserve the river Ganga?
  • What are the causes and effects of flood?