NBSE Class-9| Social Science Notes/Solutions| Chapter-7| Drainage

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I This chapter NBSE Class-9| Social Science Notes/Solutions| Chapter-7| Drainage. which is a part of the class 10 syllabus of social science for students studying under Nagaland Board of School Education:

NBSE Class-9| Social Science Notes/Solutions| Chapter-7| Drainage

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I. Choose the correct answer.

1. The drainage pattern formed by a river or stream in arid areas, where they converge towards a central depression is called

(a) The centrifugal drainage pattern 

(b) A trellis pattern

(c) A dendritic pattern

(d) None of the above

Ans:-(a) The centrifugal drainage pattern 

2. In which of the following states is the Wular lake located?

(a) Rajasthan

(b) Punjab

(c) Uttar Pradesh

(d) Jammu and Kashmir

Ans:- (a) Rajasthan

3. Which river is also known by the name ‘Oakshin Ganga’?

(a) Tapi

(b) Kaveri

(c) Mahanadi

(d) Godavari

Ans:-(d) Godavari

4. The river Narmada has its source at

(a) Satpura

(b) Amarkantak

(c) Brahmagiri

(d) Slopes of the Western Ghats

Ans:- (b) Amarkantak

5. Which one of the following lakes is a salt water lake?

(a) Sambhar

(b) Wular

(c) Oal 

(d) Gobind Sagar

Ans:-(a) Sambhar

6. Which one of the following is the longest river of the Peninsular India?

(a) Narmada

(b) Godavari

(c) Krishna

(d) Mahanadi

Ans:-(b) Godavari

7. Which river forms the Ohuadhar falls? 

(a) Narmada

(b) Tapi

(c) Kaveri

(d) Godavari

Ans:-(a) Narmada

II. Very Short Answer Type Questions

1. What is a drainage basin?

Ans:- The area of land from which a river collects water is called its drainage brain.

2. Where do the following rivers originate?

(a) Kaveri 

(b) Brahmaputra 

(c) Mahanadi 

(d) Tapi

Ans:- (a) Kaveri: Brahnagir range of the Western Ghats. 

(b) Brahmaputra: Chemayundung Glacier on the slopes of the Himalayas.

(c) Mahanadi: Chhattisgarh

(d) Tapi: The river Tapi originates from the Betul district of Madhya Pradesh in the Satpura range.

3. What is a watershed? 

Ans:- Rivers are separated from each other by heights of land, are called Watersheds.

4. What is radial pattern of rivers?

Ans:- When the streams flow in different directions from a central peak or dome like structure, is called radial pattern of rivers.

5. What is meant by a water divide? Give an example.

Ans:-Any elevated area such as a mountain or an uphold that separate two drainage basins is called a water divide. An example are the Western Ghats.

6. Name the different stages of rivers.

Ans:-The different stages of rivers are: Source of river, upper course, middle course, oxbow lake, lower course and Delta.

7. Where do the river Indus and Ganga have their origin?

Ans:-Himalayas of westem Tibet.

8. Which two peninsular rivers flow towards west?

Ans:- Narmada and Tapi..

III. Short Answer Type Questions. 

1. Differentiate between dendritic and trellis pattern of rivers.

Ans:- Dendritic pattern: It consist of a single main stream with tributaries joining like the branches of a tree.

Whereas a trellis pattern is a Rectangular shape formed when a long river is joined by short flowing streams, approximately at right angles.

2. Give any three characteristics of Himalayan Rivers.

Ans:- Three characteristics of the Himalayan River are: 

(a) These rivers have large basins.

(b) They are Perennial Rivers and will have water all throughout year.

(c) These rivers carry out intensive erosional activities.

3. Write a short note on 

(i) Mahanadi Basin 

(ii) Kaveri Basin. 

Ans:- (i) Mahanadi Basin: It originates in Chhattisgarh and flow through Orissa and reach the Bay of Bengal, its main drainage is lying in Chhattisgarh, Jharkhand, Orissa and Maharashtra.

(ii) Kaveri Basin: The River Kaveri has its source in the Brahmagir range of the Western Ghats. The basin ends at Kaveripatnam and it is shared by Karnataka, Tamil Nadu and Kerala. 

4. What is meant by the term ‘inland drainage’?

Ans:-A drainage system in which rivers do not flow into the ocean but drain their water into a lake or an inland sea is called inland drainage.

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

Ans:- Rivers have always been of great use to man. They provided early man with water to drink, and the fish they provided were to drink, and the fish they provided were valuable as food. When man learnt to build and manage boats, rivers supplied a cheap and easy way of travel. River valleys provided easy routes and fertile land. In many places, the rivers have been set to work to produce electric power. Rivers often form the boundaries of countries, as their crossings can be easily controlled.

IV. Long Answer Type Questions

1. What is the difference between peninsular rivers and Himalayan Rivers?

Ans:-The difference between peninsular rivers and Himalayan rivers are the following:

Peninsular rivers

i) They have small basins

ii) Most of the rivers are seasonal and their flow depends on rainfall.

iii) The gentle slopes cause a low intensity of erosional activity compared to other rivers.

iv) These rivers do not have many meanders.

Himalayan Rivers

i) They have large basins 

ii) They originate from the Himalayas and they receive water from rain and melting ice all the time.

iii) They carry out intensive erosional activities.

iv) When in the plains, these rivers form large meanders

2. Write notes on

(i) Ganga System 

(ii) Brahmaputra System

(iii) Indus System

Ans:-(i) Ganga System: The river Ganga rises in the Himalayas of the Indian side of the Tibet border. Most of the course of Gangas is through the Indian Territory even though its massive delta is located almost entirely in Bangladesh. It has a length of 2510 Km. It is a wide and sluggish stream which flows through one of the most fertile and densely populated region of India. It has five headstreams namely Bhagirathi, Alaknanda, Mandakini Dhauligana and Pindar. As seasonal variations occurs, the flow of the river still remains the almost the same. Its volume tends to increase as it meets tributaries and it goes into a region of heavy rainfall, in Bihar it join with its main tributaries such as Gandak Burshi Gandak, Ghugri and Kosi. In Bangladesh it joins Brahmaputra and finally flows into the Bay of Bengal.

(ii) Brahmaputra System: The Brahamaputra is one of the great rivers at Southern Asia. The rivers source lies in the Chemayungdung glacier. It flows nearly 1126 Km in an easterly direction. Throughout its upper course the river is generally known as Tsangpo. On reaching the mountain peak Nameba Barwa (775m), it takes a U turn and enters India in Arunachal Pradesh. Here it is known as Dihang river. Many tributaries like the Lohit and the Kerela joins it before it emerges near India in Assam. In Assam, the river is mighty, even in the dry season and during the rains its banks are more than 8km apart. The plains watered by the Brahamaputra streams yield abundant crops of rice, jute and mustard. Streams can navigate the river from Bay of Bengal up as far as Dibrugarh in Assam, 1287km from the Sea. The river Brahmaputra finally flows into Bay of Bengal.

(iii) Indus System: The Indus is about 2900km long. It has its origin in the Himalayas of western Tibet, near lake Mansarovar, Indus has a total drainage area of about 1,165,500 Sq.km of which 453250 Sq.Km lies in the Himalayan mountains foothills and the rest in the Semi-arid plains of Pakistan. A third of the Indus Basin is in the Indian states of the Jammu and Kashmir, Himachal Pradesh and Punjab and the rest in the Pakistan. Indus is one of the longest rivers in the world and it has five major tributaries such as The Sutlej, The Ravi, The Chenab, The Jhelum and The Beas.

The Indus enters the Indian state of Punjab 1304km from its source. At a point 77km farther, it becomes navigable. The water of the Indus is shared with India under the Indus Water Treaty regulation. Accordingly India can use only 20 percent of the total water carried by this river system. We use this water to irrigate Punjab, Haryana and Western Parts of Rajasthan.

3. Where is inland drainage found in India?

Ans:-Island drainage is found in Rajasthan. Because it is an arid and semi-arid area where the river water drains into a lake or an island sea there itself.

4. Suppose, you are travelling from Haridwar to Siliguri along the foothills of the Himalayas. Name the important rivers you will come across. Describe the characteristics of anyone of them. [HOTS]

Ans:- The important rivers that we will come across as we travel from Haridwar to Siliguri are Ganga, Ranganga, Gomati, Ghaghra, Gandak and Kosi.

The characteristics of river Ganga are:

The rover Ganga is the second major drainage system of India. This system is in fact the largest river system of India draining about 25 percent of the total geographical area of the country. The Ganga’s headstream are the Alaknanda and Bhagirathi which meet at Devaprayag to form the Ganga. In fact all the important rivers that flows between Haridwar and Siliguri are the tributaries of river Ganga they all meet Ganga at some point. In Bangladesh, Brahmaputra also joins Ganga to form the combined stream called Padma. Then it meets rivers Meghna. The waters then flow into the Bay of Bengal through numerous Channels, the largest one of which is called the Meghna estuary. It forms the Sunderbans Delta.

V. Map Work

Mark and label the following features on an outline map of India:

1. Rivers: Indus, Kaveri, Yamuna and Meghna

2. Lakes: Mansarovar, Dal, Nagarjuna Sagar, Nainital 

3. Dams: Bhakra Nangal and Hirakud

4. West flowing river: Narmada and Tapi

Additional Questions:

1. Which states do the following rivers flows through?

Ans:-a) Ganga – Flows through Uttaranchal, U.P, Bihar, Bengal, Bangladesh.

b) Narmada – Madhya Pradesh, Gujarat.

c) Krishna-Maharashtra, Karnataka and Andhra Pradesh. 

d) Godavari-Maharashtra, Madhya Pradesh, Orrisa and Andhra Pradesh.

2. What is Ganga action Plan?

Ans:- The Ganga action plan was made in 1985 to create awareness among the people not to pollute the water in the River Ganga. Rules were also made to punish those who violate the rules. The plan has removed huge quantity of sewage to keep the river Ganga clean.

3. Describe the stages of a river from the glacier to its delta.

Ans:- The development of a river valley is the combined result of the three fold action of a river. The activities can be divided into three sections such as upper course, middle course and lower course.

Upper Course: The river rises in the highland and, therefore, its upper course generally lies in the hilly or mountain areas. In its upper course a river generally flows in a straight course. Waterfall is the special feature in the upper course.

Middle Course: In the middle course of a river, the widening of a valley floor takes place over valley deepening, covering of alluvium to form a flood plain. The special characteristic feature of the middle course is the development of the loops and meanders.

Lower Course: In the lower course the work of the river is mainly depositional. The deposition of sediments on the flood plain and on the river bed becomes more significant. The river flows in a slow manner and finally changes its course as the sediments abstract on its way.

4. What is a river?

Ans:- A river is any natural stream of fresh water that flows in a definite channel.

5. What are stream?

Ans:- Narrow and not very deep rivers which are small in size are sometimes called streams.

6. What is a river bank?

Ans:- A river bank is the land on either side of the river.

7. Why ‘divides’ are called water-sheds?

Ans:- Divides are called water-sheds because they decide in which direction the rain water will flow.

8. What is centrifugal drainage pattern of rivers?

Ans:- The centrifugal drainage pattern of rivers is usually found in arid areas, where streams converge from all sides towards a central depression where there is a lake.

9. Classify the rivers based on the origin.

Ans:-Based on the origin, rivers can be classified into two

a) The Himalayas Rivers

b) The Peninsular Rivers

10. Name the important Himalayan Rivers.

Ans:-a) The Indus 

b) The Ganga 

c) The Brahmaputra are the important Himalayan Rivers.

11. What is Brahmaputra known as in its upper course or in Tibet?


12. Where does the River Narmada originate? 

Ans:-Near Amarkantak in Madhaya Pradesh.

13. Where does the famous ‘Marble Rocks’ find?


14. What is meant by the Source of a river?

Ans:- The beginning of a river is called its source.

15. Where is Pulicat Lake?

Ans:- It is in Tamil Nadu.

16. Where is Killeru Lake?

Ans:-It is in Andhra Pradesh.

17. Name the largest fresh water lake of India.

Ans:-Wular Lake.

18. Where is Wular lake?

Ans:-Jammu and Kashmir.

19. Where is Chilka Lake?

Ans:-It is in Orrisa.

20. Where is Sambhar Lake?


21. What is the special feature of Sambhar Lake?

Ans:-Sambhar Lake is salty.

22. What is ICOLD?

Ans:-It is the short form of International Commission of Large Dams.

23. What is meant by the ‘mouth’ of a river?

Ans:-The place where a river ends its flows is often called its mouth.

24. What are tributaries?

Ans:-Small rivers that join bigger rivers are called tributaries.

25. How does a ‘river system’ form?

Ans:- A large river and its tributaries form a river system.

26. How are rivers useful to man?

Ans:-Rivers are useful to man in different ways.

a) They provide water to drink and fish as valuable food. 

b) Rivers supply a cheap and easy way of travel.

c) They also help to produce electric power.

d) River valley have become a place of civilization 

e) They are also the source irrigation, navigation

f) Reservoirs constructed on the rivers have became recreation sites for swimming, boating and other water sports.

Multiple Choice Questions:

27. River Tapi flows

(a) Arabian Sea.

(b) Indian Ocean

(c) Bay of Bengal

(d) None of the Above

Ans:-(b)Arabian Sea.

28. The origin of a river is called

(a) Source

(b) Mouth

(c) Bank

(d) Basin

Ans:-(a) Source

29. The drainage pattern which has the streams flowing in different direction from a central peak or dome like structure is called ________.

(a) Dendritic Pattern

(b) Trellies Pattern

(c) Radial Patter

(d) Centrifugal Pattern

Ans:-(c) Radial Pattern

30. Which of the following is the characteristic of the peninsular rivers:

(a) They flow through shallow valleys 

(b) They are seasonal

(c) They do not have many meanders

(d) All the above.

Ans:-(d) All the above.

31. River Alakananda is the tributary of: 

(a) River Ganga

(b) River Indus

(c) River Brahamaputra 

(d) River Mahanadi

Ans:- River Ganga.

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