Extra Questions for Class 9 Geography Chapter 3 Drainage
Class 9 Social Science Geography Chapter 3 Drainage extra questions and answers available here in PDF format. Solving class 9 extra questions help students to revise the Chapter most competently. We prepared these questions with PDF as per the latest NCERT book and CBSE syllabus. Practising these questions before the exam will ensure excellent marks in the exam.
Class 9 Geography Chapter 3 Extra Questions and Answers
Very Short Answer Questions
1. What is the common characteristic of the Sambhar, Pulicat and Chilika lakes?
Answer: They are all salt water lakes.
2. Which is the largest natural inland lake in India?
Answer: The Wular lake in Jammu and Kashmir, with a maximum area of 260 sq km, is the largest natural inland lake in India.
3. The Satluj is a tributary of which river?
Answer: The river Satluj is a tributary of the Indus and joins it in Pakistan.
4. What are other names given to the Brahmaputra river?
Answer: Tsangpo is the name of the Brahmaputra in Tibet (China) and Dihang is its name in Arunachal Pradesh.
5. What is the Sunderban famous for?
Answer: Sunderban is famous for being the home of the Royal Bengal tiger.
6. Through which states in India does the river Satluj flow?
Answer: The river Satluj flows through the states of the Himachal Pradesh and the Punjab in India.
7. Which of the three rivers, the Chenab, the Ravi and the Beas, flows in India only through the state of Jammu and Kashmir?
Answer: The Chenab flows only through the state of Jammu and Kashmir in India. The Ravi and the Beas rivers flow through the Punjab and the Himachal Pradesh in India.
8. Is it true that the water in a delta is salty, as it is close to the sea?
Answer: Since, the sea is at a lower level than the river in a delta, normally the delta will not be salty.
9. Which of the rivers Beas, Ghaghara, Indus and Yamuna rises from a glacier in Uttarakhand?
Answer: The Yamuna rises from the Yamunotri glacier in Uttarakhand. The Beas rises in Himachal Pradesh, the Indus in China (Tibet) and the Ghaghara in Nepal.
10. Which is the highest waterfall in India?
Answer: The Kunchikal falls on the river Varahi in Karnataka have a drop of 455 m.
11. Why has industrial development flourished along rivers?
Answer: The reason for industries being near rivers is because of the free availability of fresh water required for industrial processes.
12. Out of the tributaries Ghaghara, Son, Kosi and Yamuna, which ones join the Ganga from the South and which from the North?
Answer: The Yamuna and Son rivers join the river Ganga from the South, while the Ghaghara and Kosi Join it from the North.
13. What is the meaning of the word ‘doab’?
Answer: In the Persian language, ‘do’ means ‘two’ and ‘ab’ mean ‘water’. So ‘doab’ means a tract of land lying between two confluent rivers
14. The Kaveri basin covers parts of which Indian states?
Answer: The Kaveri basin covers parts of Karnataka, Tamil Nadu and Kerala.
15. Which is the longest river of peninsular India?
Answer: The river Godavari, with a length of 1465 km, is the longest river of peninsular India.
16. Which type of drainage pattern develops where the river channel flows the slope of the terrain?
Answer: The dendritic pattern develops where the river channel flow the slope of the terrain.
17. What is the name of the drainage pattern which resembles the branches of a tree?
Answer: Dendritic drainage pattern resembles the branches of a tree.
18. What do you understand by the term “Drainage Basin”?
Answer: The area drained by a single river system is called “Drainage Basin”.
19. Name the place where the Ganga emerges from the mountains on to the plains.
Answer: At Haridwar, the Ganga emerges from the mountains on to the plains.
20. Name the Indian state where river Brahmaputra enters in India.
Answer: At the Indian state of Arunachal Pradesh river Brahmaputra enters in India.
21. Which is the longest river of the peninsular plateau?
Answer: River Godavari is the longest river of peninsular plateau.
22. Which river is known as “Dakshin Ganga”?
Answer: The Godavari, because of its length and area it cover is known as ‘Dakshin Ganga’.
23. Which is the largest freshwater lake of India?
Answer: The Wular lake is the largest freshwater lake of India.
24. Name the saline water lake located in Rajasthan,
Answer: The saline water lake located in Rajasthan is the Sambhar lake.
25. Name the Indian states through which Kaveri river passes.
Answer: Kaveri river passes through Indian states of Karnataka, Kerala and Tamil Nadu.
26. At which place do the Satluj, the Beas, the Ravi, the Chenab and the Jhelum rivers join together to enter the river Indus?
Answer: The Satluj, the Beas, the Ravi, the Chenab and the Jhelum rivers join together to enter river Indus at Mithankot in Pakistan.
27. What is the origin of the River Krishna?
Answer: River Krishna rises from a spring near Mahabaleshwar (Maharashtra).
28. Which drainage pattern does the river Ganga forms?
Answer: River Ganga forms dendritic drainage pattern.
29. Where does river Narmada has its source?
Answer: The Narmada rises in the Amarkantak hills in Madhya Pradesh.
30. Which is the largest brackish water lake in India? Where it is located?
Answer: The Chilika lake is the largest brackish water lake in India. It lies in the state of Odisha to the South of Mahanadi delta.
31. What is an ox-bow lake?
Answer: A crescent shaped lake formed when a meander of a river or stream is cut-off from the main channel due to siltation.
32. Name five tributaries of the river Ganga.
Answer: Any five of the following Yamuna, Son, Ghaghara, Gandak, Kosi, Mahananda, Mahakali and Gomti.
33. What is a water divide?
Answer: Any elevated area, like a mountain or an upland, which divides two drainage basins.
34. Name the river known as the ‘Sorrow of West Bengal’. Why is it given this name?
Answer: Damodar river is known as the ‘Sorrow of West Bengal’. It is given this name because it is prone to floods every year, causing death and destruction due to overflowing of its banks.
35. What is a braided stream?
Answer: A stream consisting of multiple small, shallow channels that divide and recombine numerous times, forming a pattern resembling the strands of a braid.
36. Name five rivers rising in the Western Ghats.
Answer: Godavari, Krishna, Kaveri, Tungabhadra, Ghatprabha and many others.
37. Name three major rivers of the subcontinent which originate beyond the Himalayas.
Answer: The three major rivers are the Indus, Saduj and the Brahmaputra.
38. Which river has the largest basin in India?
Answer: The largest basin in India is of the Ganga river with a drainage area of 862769 sq km.
39. Find out the name of the highest waterfall in India.
Answer: The highest waterfall in India is on the Varahi river in Shimoga district of Karnataka. The name of the waterfall is Kunchikal falls and its height is 455 metres (1493 ft).
40. What is meant by a water divide? Give an example.
Answer: Any elevated area such as a mountain or an upland that separates two drainage basins is called a water divide. An example are the Western Ghats.
41. Which is the largest river basin in India?
Answer: The Ganga Basin is the largest river basin in India.
42. Where do the rivers Indus and Ganga have their origin?
Answer: The river Indus rises in Tibet, near lake Mansarowar and the Ganga originates at the Gangotri glacier. Both of them have their origin in the Himalayas.
43. Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
Answer: The two headstreams of the Ganga are the Bhagirathi and Alaknanda. They meet at Devaprayag in Uttarakhand to form the Ganga.
44. Which two peninsular rivers flow through a trough?
Answer: Narmada and Tapi are two Peninsular rivers which flow through a trough.
45. What does the term ‘Drainage’ mean?
Answer: The term ‘drainage’ describes the river system of an area.
46. What is a ‘drainage basin’?
Answer: The area drained by a single river system is called a drainage basin.
47. Which part of the land is called ‘water divide’?
Answer: Any elevated area, such as a mountain or an upland separates two drainage basins. Such an upland is known as a ‘water divide’.
48. Into which two major groups are Indian rivers divided?
Answer: The Indian rivers are divided into two major groups
(i) The Himalayan Rivers,
(ii) The Peninsular Rivers.
49. Which rivers are called perennial?
Answer: Perennial rivers are the ones which have water throughout the year. These rivers receive water from rain as well as from melted snow from the lofty mountains.
50. What do Himalayan rivers do in their upper course?
Answer: The Himalayan rivers perform intensive erosional activity in their upper courses and carry huge loads of silt and sand.
51. What do Himalayan rivers do in the middle and lower course?
Answer: In the middle & lower courses these rivers form meanders, ox-bow lakes and many other depositional features in their flood plains. They also have well developed deltas.
52. Which river has the largest basin in India?
Answer: River Ganga
53. How dendritic pattern is formed by the river?
Answer: The dendritic pattern develops where the river channel follows the slope of the terrain. The stream with its tributaries resembles the branches of a tree, thus, the name dendritic is given.
54. How is Trellis Pattern developed by a river?
Answer: A river joined by its tributaries, at approximately right angles, develops a trellis pattern. A trellis drainage pattern develops where hard and soft rocks exist parallel to each other.
55. How is rectangular drainage pattern formed?
Answer: A rectangular drainage pattern develops on a strongly jointed rocky terrain.
56. When does a Radial pattern of drainage develop?
Answer: The radial pattern develops when streams flow in different directions from a central peak or dome like structure.
57. Why are Peninsular rivers called seasonal?
Answer: A large number of peninsular rivers are seasonal as their flow is dependent on rainfall and even the large rivers have reduced flow of water in the dry season.
58. Name the rivers which originate in Central Highlands & flow towards the west.
Answer: Rivers Narmada and Tapi.
59. What is a river system?
Answer: A river alongwith its tributaries may be called a river system.
60. From where does river Indus originate?
Answer: River Indus originate in Tibet, near Lake Mansarowar.
61. Name the tributaries which join Indus in Kashmir.
Answer: The Zaskar, the Nubra, the Shyok and the Hunza are the tributaries which join river Indus in the Kashmir region.
62. Which are the main tributaries of river Indus?
Answer: The Satluj, the Beas, the Ravi, the Chenab and the Jhelum are the main tributaries of river Indus.
63 What is the total length of river Indus?
Answer: It is about 2,900 kms.
64. In which states of India, Indus Basin is located?
Answer: In India in the states of Jammu & Kashmir, Himachal Pradesh and Punjab, the Indus basin is located.
65. What are the regulations of Indus Water Treaty of I960?
Answer: According to the regulations of the Indus Water Treaty(1960), India can use only 20 percent of the total water carried by Indus river system.
67. From which place does river Ganga originate?
Answer: The head waters of the Ganga, called the ‘Bhagirathi’ is fed by the Gangotri Glacier & joined by the Alaknanda at Devaparyag in Uttarakhand.
68. Name the main tributaries of the river Ganga.
Answer: The Yamuna, the Ghaghara, the Gandak and the Kosi are the main tributaries of river Ganga.
69. Which rivers rise from Nepal Himalaya?
Answer: The Ghaghara, the Gandak and the Kosi rise in the Nepal Himalaya.
70. Which tributaries join Ganga from peninsulas uplands?
Answer: The Chambal, the betwa and the son are the tributaries.
71. How is Sunderban Delta formed?
Answer: The waters of two mighty rivers: the Ganga and the Brahmaputra flows into the Bay of Bengal and the delta formed by these rivers is known as Sunderban Delta. It is world’s largest delta.
72. How is Sunderban Delta named?
Answer: The Sunderban delta has derived its name from Sundari trees which grow well in marshland.
73. What is the total length of the river Ganga?
Answer: The total length of the river Ganga is 2,500 km.
74. Which place is located on water divide of river Ganga and the Indus?
Answer: Plains of Ambala.
75. From where does river Brahmaputra originate?
Answer: The Brahmaputra rises in Tibet, east of Mansarovar lake very close to the sources of the Indus and the Satluj.
76. From where does river Brahmaputra enter India?
Answer: On reaching the Namcha Barwa, Brahmaputra takes a ‘U’ turn and enters India in Arunachal Pradesh through a deep gorge.
77. Which tributaries join Brahmaputra in Assam?
Answer: It is joined by the Dibang, Lohit, Kenula to become Brahmaputra.
78. By what name is Brahmaputra known in Tibet and Bangladesh?
Answer: In Tibet it is known as Tsang-Po and in Bangladesh it is called Jamuna.
79. Why does river Brahmaputra carry less water in Tibet?
Answer: In Tibet, the river carries a smaller volume of water & less silt as it is a cold and a dry area.
80. How does Brahmaputra river cause damage in Assam during rainy season?
Answer: Every year during the rainy season, the river overflows its banks, causing widespread devastation due to floods in Assam.
81. Name the major Peninsular rivers.
Answer: The Mahanadi, the Godavari, the Krishna and the Kaveri.
82. Which two peninsular rivers form-estuaries?
Answer: Narmada and Tapi.
83. Which Peninsular rivers form delta?
Answer: The Mahanadi, the Godavari, the Krishna & the kaveri.
84. At what place Narmada river rises?
Answer: The Narmada rises in Amarkantak hills in Madhya Pradesh.
85 How does river Narmada create picturesque locations?
Answer:The ‘Marble Rocks’ near Jabalpur where Narmada flows through a deep gorge and the ‘Dhuadhar falls’ where the river plunges over steep rocks are some of the example.
86. From which states Narmada river Hows?
Answer: River Narmada flows in Madhya Pradesh and Gujarat.
87. From where does River Tapi originate?
Answer: The Tapi rises in the Satpura range in Betui district of Madhya Pradesh.
88. Which are the main west flowing rivers of Western Ghats?
Answer: Sabarmati, Mahi, Bharathpuzha and Periyar.
89. Which river is the largest Peninsular river?
Answer: The Godavari, it’s length is about 1500 km.
90. The Godavari rises from which place?
Answer: The Godavari rises from the slopes of Western Ghats in the Nasik district of Maharashtra.
91. In which states Godavari’s basin lies?
Answer: Maharashtra, Madhya Pradesh, Odisha and Andhra Pradesh.
92. Name the tributaries of river Godavari.
Answer: The Purna, the Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga.
93. Which river is called ‘Dakshin Ganga’?
Answer: Godavari is called ‘Dakshin Ganga’ because of its length and the area it covers.
94. From where the Mahanadi river rises?
Answer: The Mahanadi rises in the highlands of Chhattisgarh.
95. What is length of river Mahanadi?
Answer: It is about 860 km.
96. From which states river Mahanadi passes?
Answer: River Mahanadi passes from Maharashtra, Chhattisgarh, Jharkhand and Odisha.
97. From which region River Krishna rises?
Answer: River Krishna rises from a spring near Mahabaleshwar.
98. What is the length of river Krishna?
Answer: The Total length of river Krishna is about 1400 km.
99. Name the major tributaries of River Krishna.
Answer: The Tungabhadra, the Koyana, the Ghatprabha, the Must and the Bhima.
100. In which states the basin of river Krishna lies?
Answer: The basin of river Krishna is shared by Maharashtra, Karnataka and Andhra Pradesh.
101. From which place river Kaveri originates and at which place it merges?
Answer: The Kaveri rises in Brahmagri range of the Western Ghats and it reaches the Bay of Bengal in South of Cuddalore in Tamil Nadu.
102. What is the total length of river Kaveri?
Answer: The Total length of river Kaveri is about 760 km.
103. Name the tributaries of river Kaveri?
Answer: Its main tributaries are Amravati, Bhavani, Hemavati and Kabini.
104. Which regions of India are drained by river Kaveri?
Answer: Its basin drains parts of Karnataka, Kerala and Tamil Nadu.
105. What is ‘Shivasamudram’? What is its use?
Answer: The river Kaveri makes the second biggest waterfall in India. It is known as Shivasamudram. The hydroelectric power generated from the falls is supplied to Mysore, Bangalore and the Kolar Gold Field.
106. How are lakes formed?
Answer: There are some lakes which are the result of the action of glaciers and ice sheets, while the others have been formed by wind, river action and human activities.
107. How ox-bow lakes are formed?
Answer: A meandering river across a flood plain forms cut-offs that later develop into ox-bow lakes.
108. How lagoons are formed?
Answer: Lagoons are salt water lakes which are formed with spits and bars in the coastal areas, for example, the Chilka Lake.
109. How lakes become seasonal?
Answer: Lakes in the region of inland drainage are sometimes seasonal. For example, Sambhar lake of Rajasthan.
110. What are fresh water lakes?
Answer: Fresh water lakes are mostly found in the Himalayan region. They are formed when glacier dug out a basin, which was later filled with snowmelt water.
111. Name some of the fresh water lakes of India.
Answer: The Wular lake. The Dal lake, Bhimtal, Nainital, Loktak and Barapani.
112. How man-made lakes are formed?
Answer: The drainage of rivers for the generation of hydroelectric power also led to the formation of lakes called man-made lakes. For example. Guru Gobind Sagar Lake (Bhakra Nangal Project).
113. What is the importance of lakes?
Answer: Lakes moderate the climate of surroundings, maintain the aquatic ecosystem, enhance natural beauty, help develop tourism and provide recreation.
114. How rivers help in an agricultural country like India?
Answer: Rivers help in irrigation, navigation, hydro-power generation to help the farmers in their production and marketing.
Short Answer Type Questions
1. What is the major objective of the National River Conservation Plan (NRCP)?
Answer: Under this action plan, pollution abatement works in Indian rivers are being taken up. Initially, 215 schemes of pollution abatement have been sanctioned. So, far 69 schemes have been completed under this plan. A total of one million litres of sewage is targeted to be intercepted, diverted and treated.
2. Identify the rivers of which the following are tributaries: the Gandak, the Dibang, the Ganga and the Tungabhadra.
Answer: The Gandak is a tributary of the Ganga, the Dibang is a tributary of the Brahmaputra, the Ganga is a tributary of the Meghna (in Bangladesh) and the Tungabhadra is a tributary of the Krishna.
3. List three salient features of inland salt lakes.
Answer: The three features are
(i) They are found in arid or semi-arid regions of the country.
(iii) They dry up during summers.
(iii) They are fed by short and intermittent streams.
4. Which river in South India receives water both in summer and winter?
Answer: The river Kaveri rises in the Western Ghats and thus receives water from the summer monsoon. Since, it flows through Tamil Nadu into the Arabian sea, it receives rainfall from the winter monsoon also.
5. Which river flows for the longest length in India?
Answer: The Ganga river flows for 2525 km in India. Although other rivers like the Brahmaputra and Indus may be longer in their total length, their length of flow in India is much less than that of the Ganga.
6. Which of the lakes out of Nagaijuna Sagar, Loktak, Chilika and Gobind Sagar are artificial lakes?
Answer: Nagarjuna Sagar is an artificial lake created by damming the Krishna river. Gobind Sagar lake in Himachal Pradesh has been artificially created by damming the Satluj river with the Bhakra dam.
7. What is the Indus Water Treaty?
Answer: The Indus Water Treaty is a water sharing treaty of the Indus basin between India and Pakistan. According to it, India can use only the waters of the Indus tributaries the Satluj, the Beas and the Ravi (comprising about 20 per cent of the water).
8. Name three famous waterfalls in India and the rivers on which they are situated.
Answer: Besides the waterfalls listed here, there are many others. The following are three famous waterfalls in India
| Name of Waterfall | River on Which Situated |
| Jag falls | Sharavathi river (Shimoga, Karnataka) |
| Langshiang falls | Kyinshi river (West Khasi hills, Meghalaya) |
| Barehipani falls | Budhabalanga river (Mayurbhanj Odisha) |
9. In the radial drainage pattern, why do streams flow in all directions from a central point?
Answer: The source of streams in a radial drainage pattern is an uplifted point like a mountain or volcano and the streams flow down by gravitation. The terrain of the mountain determines the path of these streams.
10. Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
Answer: In Tibet, the river Indus known as Tsangpo carries a smaller volume of water and less silt as it is a cold and dry area. In India, the river carries a large volume of water and considerable amount of silt because it passes through a region of high rainfall.
11. What you understand by the terms ‘lagoon’ and “estuary”?
Answer: Logoon : A shallow body of water, especially one separated from a sea by sandbars or coral reef is called lagoon. Estuary Estuary is widening channel of river where it nears the sea with a mixing of fresh water and salt water. It is a party enclosed,coastal body of brakish water where one or more rivers are discharging.
12. How growing demand of water from rivers, affects the quality of water?
Answer: More and more water is drained out of the rivers for growing domestic, municipal, industrial and agricultural demands of water, which reduces their volume. On the other hand, a heavy load of untreated sewage & industrial effluents are emptied into the rivers, affecting the quality of water.
13. What does ‘drainage’ mean? What is a ‘drainage basin’?
Answer: (i) The term ‘drainage’ means the river system of an area.
(ii) Some small streams flowing from different directions come together to form the main river, which ultimately drains into a large water body. The area drained by a single river system is called a ‘drainage basin’.
14. What is meant by ‘water divide’? Give an example.
Answer: Any elevated area such as a mountain or a plateau that separates two drainage basins is known as a ‘water divide’.
For example, Ambala is located at the water divide between the Indus and Ganga rivers. It does not receive water from either of the two rivers.
15. From where does the river Indus originate and which tributaries join the main river?
Answer: (i) Several tributaries such as the Zaskar, Nubra, Shyok and the Hunzajoin the river Indus in Kashmir.
(ii) The Satluj, Beas, Ravi, Chenab andJhelum rivers join together to enter the Indus near Mithankot in Pakistan.
16. From where does the river Ganga originate and which tributaries join it?
Answer: The river Ganga originates from the Gangotri glacier as ‘Bhagirathi’. Then it is joined by Alaknanda at Devaprayag in Uttarakhand. The Ganga is joined by many rivers from the Himalayas such as Yamuna, Ghaghara, Gandak and the Kosi rivers. The river Yamuna originates from the Yamunotri glacier, but joins the river Ganga at Allahabad. The main tributaries which come from the peninsular uplands are the Chambal, the Betwa and the Son.
17. Prepare a short note on the ‘Sunderban Delta’.
Answer: The Sunderban Delta is the world’s largest and the fastest growing delta. Filled by various tributaries, the river Ganga reaches West Bengal. This is the northernmost part of the Ganga Delta. From here, the Bhagirathi-Hooghly (a distributary) flows southwards towards the deltaic plains and the Bay of Bengal. The main stream flows southwards into Bangladesh and is joined by Brahmaputra, known as Meghna. This mighty river (with waters from Ganga and Brahmaputra) forms the deltaic plains and then flows into the Bay of Bengal. It derives its name from the Sundari tree which grows in marshland.
18. How does the Brahmaputra river enter India? Which are its tributaries?
Answer: (i) The Brahmaputra rises in Tibet, near the Mansarovar lake. Then it flows eastwards, parallel to the Himalayas. On reaching the Namcha Barwa, it takes a U-turn and enters India into Arunachal Pradesh through a deep gorge. (ii) Its tributaries are – the Dibang, Lohit and Kenula.
19. From where does the river Narmada originate? How is the Narmada basin formed?
Answer: The Narmada river rises in the Amarkantak hills in Madhya Pradesh. From here, it flows towards the west in a rift valley. In Jabalpur, it passes through a deep gorge of marble rocks’. It also forms the ‘Dhuadhar falls’. It passes through the states of Madhya Pradesh and Gujarat.
20. Prepare a short note on the river Tapti.
Answer:(i) The Tapti rises in the Satpura ranges in Betui district of Madhya Pradesh.
(ii) It also flows in a rift valley parallel to the Narmada river.
(iii) Its basin covers parts of Madhya Pradesh, Gujarat and Maharashtra.
21. Give a brief description of ‘Dakshin Ganga’.
Answer: (i) The Godavari river is the largest Peninsular river.
(ii) It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra.
(iii) Its length is 1,500 km and it drains into the Bay of Bengal.
(iv) Its drainage basin is also the largest among the peninsular rivers.
(v) Its tributaries are?the Puma, Wardha, Pranhita, Manjra, Wainganga and the Penganga. (vi) This basin covers parts of Maharashtra, MP, Odisha and Andhra Pradesh.
22. What do you know about the Mahanadi river?
Answer: (i) The Mahanadi rises in the highlands of Chhattisgarh.
(ii) It flows through Odisha to reach the Bay of Bengal.
(iii) The length of the river is about 860 km.
(iv) Its drainage basin is shared by the states of Maharashtra, Chhattisgarh, Jharkhand and Odisha.
23. From where does the river Krishna originate and name its tributaries?
Answer: The river Krishna rises from a spring near Mahabaleshwar. The Tungabhadra, Koyna, Ghatprabha, Musi and the Bhima are some of its tributaries.
24. Make a comparison in tabular form between the East flowing and West flowing rivers of the Peninsular plateau. Or Differentiate between East flowing and West flowing rivers of Peninsular plateau. Mention their name also. Or Differentiate between the salient features of East flowing and West flowing rivers of Peninsular India.
Answer: Comparison between the East/lowing and West flowing rivers of the Peninsular plateau
| East Flowing Rivers | West Flowing Rivers |
| These rivers originate from the Western Chats and flow Eastwards. | These rivers originate in central India and flow Westwards. |
| These rivers flow into the Bay of Bengal. | These rivers flow into the Arabian sea. |
| These rivers form deltas at their mouths. | These rivers form estuaries at their mouths. |
| They carry larger amount of water. | They carry a lesser amount of water. |
| Examples are Mahanadi, Godavari, Krishna and Kaveri. | Examples are Narmada and Tapi. |
25. Explain what life would be like if freshwater is not available.
Answer: For survival, man depends on water. It circulates and goes through our bodies, replenishing nutrients and carrying away waste materials. Without freshwater, no activities of human beings and life would be possible. Seawater is salty and it cannot substitute for freshwater. Life as we know it, will not be there. No, trees will be able to grow and no land based animals can survive. Even birds will not exist.
26. Describe inland drainage, giving its main features.
Answer: When rivers do not reach a sea or ocean, but empty their water in an inland sea or lake, this is known as inland drainage. Its main features are (i) The streams joining lakes or inland seas are fed by rainwater. (ii) During the rainy season, we may have flash floods and during other seasons they may dry up. (iii) In some cases they may form salt water lakes, like the Sambhar lake in Rajasthan.
27. Make a comparison in tabular form between a delta and an estuary.
Answer: Comparison between a delta and an estuary
| Delta | Estuary |
| These are triangular deposits made by rivers at their mouths. | These are sharp edged mouths of rivers without any deposits. |
| Formed in regions of low tides and coastal plaints. | Formed in regions of high tides and rift valleys. |
| These are agriculturally fertile lands. | They are not agriculturally fertile lands |
28. List the differences between glaciers and rivers.
Answer:
| Feature | Glaciers | Rivers |
| Composition and speed | It is composed ice moving at a very slow speed. | It is composed of water flowing at a faster speed. |
| Location | These are found either on snow-capped mountains or in higher latitudes. | These are found from mountain tops to the oceans and all latitudes. |
| Dimensions | They are wide and deep, filling a whole valley. | They are shallower and confined to a narrower channel. |
29. Distinguish between a tributary and a distributary.
Answer: A tributary is a stream which flows into a main stream (or parent) river. A tributary does not flow directly into a sea, ocean or lake. Tributaries and the main stream river drain the surrounding drainage basin of its surface water and groundwater. The reverse to a tributary is a distributary, a river that branches off and flows away from the main stream. The Yamuna is a tributary of the Ganga, whereas the Hugli is a distributary of the Ganga.
30. Make a list of natural and artificial lakes with the help of the atlas.
Answer: Natural Lakes: Wular lake, Dal lake, Nainital lake, Bhimtal lake, Loktak lake, Barapani lake, Chilika lake, Sarnbhar lake, Pulicat lake, Kolleru lake, Vembanad lake.
Artificial Lakes: Guru Gobind sagar, Rana Pratap sagar, Nizam sagar, Nagarjuna sagar, Hirakud.
Long Answer Type Questions
1. Why are rivers important for the country’s economy?
Answer: Rivers are important for the country’s economy because water from the rivers is a basic natural resource is essential for various human activities. The importance of the rivers for the country’s economy are
(i) The rivers provide water for irrigation.
(ii) They provide fertility to the soil.
(iii) They are useful for navigation.
(iv) They help to generate hydroelectricity.
(v) They help to develop tourism.
(vi) They provide water for various domestic uses.
(vii) They provide livelihood to fishermen.
(viii) They help to moderate the climate and environment of nearby areas.
2. What is a river pattern? Name any four patterns formed by the rivers?
Answer: The streams within a drainage basin form certain patterns depending on the slope of land, underlying rock structure as well as the climatic conditions of the area. These patterns are known as drainage patterns.
The four patterns are
(i) Dendritic Pattern The river and its tributaries follow the slope of the terrain just like the branches of a tree.
(ii) Rectangular Pattern This occurs on a strongly jointed rocky terrain.
(iii) Trellis Pattern This develops where hard and soft rocks exist parallel to each other, so that the tributaries join the river at almost right angles.
(iv) Radial Pattern This pattern develops when streams flow in different directions from a central peak or dome like structure.
3. Explain any three features of peninsular rivers.
Answer: The three features of peninsular rivers are
(i) A large number of peninsular rivers are seasonal, as their flow depends on rainfall.
(ii) These rivers have shorter and shallower courses.
(iii) Most of the peninsular rivers originate in the Western Ghats and flow towards the Bay of Bengal.
4. Describe any three features of the Himalayan rivers. Or Explain main features of rivers originating from the Himalayas.
Answer: The three features of the Himalayan rivers are
(i) Most of the Himalayan rivers are perennial. It means that they have water throughout the year.
(ii) The Himalayan rivers have long courses from their source to the sea.
(iii) They perform intensive emotional activity in their upper courses and carry huge loads of silt and sand.
5. Describe the Indus river system on the following heads (i) Source (ii) Any two tributaries (iii) Indus Water Treaty.
Answer: (i) Source The river Indus rises in Tibet, near lake Mansarowar.
(ii)Tributaries Tributaries of Indus river system are the Zaskar, the Nubra, the Shyok, the Hunza, the Satluj, the Beas, the Ravi, the Chenab and the Jhelum.
(iii) Indus Water Treaty According to the regulations of the Indus Water Treaty, India can use only 20 per cent of the total water carried by the Indus river system. This water is use for irrigation in the Punjab, the Haryana, the Southern and the Western parts of Rajasthan.
6. Why are the rivers of the Western coastal plains short?
Answer: The Western Ghats run North-South very near to the Arabian sea coast and provides a prominent watershed in the peninsular India. So, the coastal plains between the Western Ghats and the Arabian sea coast are very narrow. Hence, the coastal rivers flowing Westward from Western Ghats are very narrow. Sabarmati, Periyar rivers are example of such rivers.
7. Describe the three main features of the Ganga river system.
Answer: The three main features of the Ganga river system are
(i) The length of the Ganga is 2500 km. It is India’s longest river.
(ii) It has many tributaries which join it from both sides and form the Ganga river basin. It has dendritic drainage pattern.
(iii) The Ganga originates from the Gangotri glacier. The headwater of the Ganga is called ‘Bhagirathi’. It joins Alaknanda at Devaprayag in Uttarakhand. At Haridwar the Ganga emerges from the mountains on to the plains.
8. (i) How are the most of the freshwater lakes in the Himalayan region formed? Give two examples of freshwater lakes of this region.
(ii) How is Sambhar lake useful?
Answer:(i) Most of the freshwater lakes are in the Himalayan region. They are of the glacial origin. They are formed when glaciers dug out a basin, which was later filled with snowmelt. Examples of such lakes are Bhimtal, Nainital, Dal lake. etc. India’s largest freshwater lake is the Wular lake.
(ii) Sambhar lake is India’s largest inland salt water lake. It is located in Rajasthan in an inland drainage. It is important source of salt in India. It is famous for production of edible salt here.
9. Give four characteristics of the Ganga Brahmaputra delta.
Answer: The four characteristics of the Ganga Brahmaputra delta are
(i) The Ganga Brahmaputra delta, also named Ganga delta, Sunderban delta or Bengal delta is situated in Bangladesh and Paschim Banga state of India, where the Ganga and Brahmaputra rivers discharge into the Bay of Bengal. The total catchment area of the rivers is 1.72 million sq km.
(ii) It is the world’s largest delta, with a surface area of 1 lakh sq km.
(iii) It is among the most fertile regions in the world. With more than 130 million inhabitants, this belongs to the most densely populated areas in the world (1300 inhabitants/sq km).
(iv) Downstream of the confluence, the river is named Padma. About halfway to the ocean the Meghna joins the Padma.
10. Explain the use of salt water lakes in India with particular reference to Chilika and Sambhar lakes.
Answer: The Sambhar lake is India’s largest saline lake and has made Rajasthan the third largest salt producing state in India. It produces about 2 lakh tonnes of clean salt every year. Salt is produced by evaporation of brine. This lake is also recognised as a wetland of international importance because it is a key wintering area for flamingos and other birds that migrate from Northern Asia. Chilika lake in Odisha is the largest brackish water lake in India. It is the wintering ground for migratory birds on the Indian sub continent. The lake is home to a number of threatened species of plants and animals. It is an ecosystem with large fishery resources sustaining 150000 fishermen living nearby.
11. Discuss the significant difference between the Himalayan and the Peninsular rivers. Or Give any three differences between peninsular and Himalayan rivers.
Answer: The three differences between peninsular and Himalayan rivers are
| Himalayan Rivers | Peninsular Rivers |
| They rise from glaciers or springs in high mountains. | They rise from plateaus and highlands. |
| Perennial in nature due to originating from glaciers. | Seasonal as they get water from rainfall. |
| Only suitable for generation of hydroelectricity in hilly regions, as they are slow flowing in the plaints. Dams need to be built to create waterfalls. | They flow at high speed due to form waterfalls, thus being suitable for hydroelectricity. Generation. |
12. Explain how pollution is caused to river water and what action the government is taking to minimise it.
Answer: Due to the requirements of the increasing population, large amounts of industrial effluents and untreated sewage are released into drains which ultimately flow into rivers. Further, due to requirements in agriculture and industry, larger amounts of water are being drained out from rivers. All this has led to increased pollution of the water remaining in the rivers. The government has launched various action plans to clean rivers. The major offensive in this regard is the National River Conservation Plan (NRCP), which envisages pollution abatement in 38 major rivers covering 172 towns in 20 states currently. Under this plan, 4400 million litres of sewage is targeted to be intercepted, diverted and treated every day.
13. Describe the various drainage patterns of rivers giving some examples of Indian rivers.
Answer: There are basically four drainage patterns of rivers
(i) Dendritic Pattern This is the most common pattern followed by rivers like the Ganga. This develops where the river channel follows the slope of the terrain. The stream with its tributaries resembles the branches of a tree.
(ii) Trellis Pattern Short tributaries meet long trunk streams at near right angles. They are formed on sedimentary rocks of different resistance to erosion. An example is the Narmada river.
(iii) Rectangular Pattern Straight tributaries meet straight trunk streams with bends at almost right angles. These are formed on faulted or fractured bedrock.
(iv) Radial Pattern The streams flow outward from a well defined central point like a volcano or other round uplift of land.
14. Explain the differences between the Indus basin and the Ganga basin in tabular form.
Answer:
| Indus Basin | Ganga Basin |
| Formed by the Indus river and its tributaries like the Ravi, Chenab, Satluj, Jhelum, Beas, etc. | Formed by the Ganga river and its tributaries like the Yamuna, Son, Ghaghara, Gomati, Kosi, Gandak, etc. |
| Located in Jammu and Kashmir, Punjab, Haryana, Himachal Pradesh and Rajasthan (besides Pakistan). | Located in Uttarakhand, Haryana, Uttar Pradesh, Bihar, Madhya Pradesh. Jharkhand and Paschim Banga (besides Bangladesh). |
| Indus river flows for 3180 km (including China and Pakistan).Most of its tributaries flow from North-West to South-West. | Ganga river flows for 2506 km (including Bangladesh). |
| It has fertile land and a dense network of canals for irrigation. | Irrigation facilites required are less as it has high rainfall. |
| Separated from the Ganga basin by the Ambala Saharanpur water divide. | Spreads from Ambala in the North-West to Sunderban in the South-East. |
16. What are the causes of water pollution in rivers and lakes?
Answer: Water in rivers and lakes is being reduced as the requirements of rapid urbanisation, population growth and industrialization cause more water to be drained out from them. In place of this, huge amounts of untreated sewage and industrial effluents are being emptied into the rivers and lakes. This has caused the water bodies to become highly polluted. Human ashes (due to cremation near water bodies), dead animals and leaching out of nitrogen compounds from fertilised agricultural lands also increase the pollution. Nutrient run-off in storm water from “sheet flow” over an agricultural field or a forest is also another cause.
17. State some economic benefits of rivers and lakes.
Answer: Lake (i) Lakes help to regulate the flow of rivers.
(ii) Lakes help to prevent flooding during rainy season.
(iii) During the dry season, lakes help to maintain an even flow of water.
(iv) Lakes can also be used for developing hydelpower.
(v) Lakes provide opportunities for fishery development.
(vi) They moderate the climate of the surroundings and maintain the acquaric ecosystem. (viii) They enhance natural beauty and help to develop tourism and provide recreation, e.g., Dal lake and Naini lake at Nainital. Rivers
(i) They help to develop hydel power.
(ii)They provide water for irrigation for drinking and other requirements.
(iii) They help to develop fisheries.
18. The textbook states: “Imagine that if Srinagar, Nainital and other tourist places did not have a lake, would they have been as attractive as they are today? Have you ever tried to know the importance of lakes in making a place attractive to tourists?” Can you answer these questions?
Answer: Definitely, Srinagar without die Dal lake will not attract so many tourists. Similarly, Nainital without the Naini lake will be bereft of tourists. Avast expanse of bright blue water in the midst of dense forests, lofty mountains or barren landscape is marvellous and looks picturesque at dawn, sunset or during full moon nights. The view of a lake shimmering in the spring sunshine is marvellous. The lakes declared as water bird sanctuaries are like fairylands for birds. Shorelines or banks of lakes attract both humans and a diverse community of plants and animals. The biodiversity of lakes make them important as natural resources for tourism. Further, the usage of lakes for sports, entertainment, swimming, fishing, etc is of great importance to the public. Use of lake shores for residential, commercial development and recreation has increased the world over. However, through years of neglect, the lake water has been allowed to deteriorate. This should be looked into by the concerned authorities before lake tourism comes to a stop due to the pollution in the lakes.
19. Rivers are very important for development in India? Explain. Or Explain any three reasons for the significance of rivers for economy of a country. Or Rivers have been of fundamental importance throughout human history? How do rivers affect economy of a country? Explain or Highlight the role of rivers in agricultural economy like India. Write any three points.
Answer: Rivers are known as the lifeline of human civilisation. Rivers have been of fundamental importance throughout the human history. Water from the river is a basic natural resource, essential for various human activities. The river banks have attracted the settlers from ancient times. These settlements have also become big cities. The three points are
(i) The rivers for irrigation, navigation, hydropower generation is of special significance particularly to a country like India, where agriculture is the major source of livelihood for majority of its population.
(ii) River water is used for providing irrigation facilities through various canals. Multi-purpose dams have been constructed on the Indian rivers which provides hydro-electricity, irrigation facilities, navigation, afforestation, etc.
(iii) Rivers are considered of great cultural significance in Indian culture. Many cultural activities like Kumbh melas are organised on river banks in every part of India. Indian rivers like the Ganga form vast basins that are considered as one of the most agriculturally productive part of the world. Indian rivers host many religious, cultural and picturesque tourist spots that are of great significance to tourism industry which is a great source of income to a country’s economy.
20. How lakes are of great value to human beings? State any six importance’s, Or What is lake? Explain the importance of lakes. Or Describe any three benefits of lakes?
Answer: Lake is a large body of water that is entirely surrounded by land. Lake water can be fresh or more rarely salty or saline.
Importance of lakes are
(i) Lake are of great value to human beings. It helps to regulate the flow of a river.
(ii) During heavy rainfall, it prevents flooding and during the dry season, it help to maintain an even flow of water.
(iii) Lakes can also be used for developing hydel power. They moderate the climate of the surroundings maintain the aquatic ecosystem, enhance natural beauty, help develop tourism and provide recreation.
21. Explain the ‘National River Conservation Plan’ (NRCP) in brief.
Answer: The central government sponsored scheme of National River Conservation Plan (NRCP) is being implemented by the central government jointly with the state governments on a cost-sharing basis. The pollution abatement works under NRCP presently covers polluted stretches of 39 major rivers and 185 towns spread over 20 states in the country. The activities of Ganga Action plan (GAP) Phase-1 initiated in 1985, were declared closed on 31st March, 2000. The steering committee of the National River Conservation Authority reviewed the progress of the GAP and necessary correction on the basis of lessons learnt and experience gained from GAP Phase-I. These have been applied to the major polluted rivers of the country by the NRCP. The Ganga Action Plan (GAP) Phase-II has been merged with NRCP. A total of 215 schemes of pollution abatement have been sanctioned. So far, 69 schemes have been completed under this action plan. A million litres of sewage is targeted to be intercepted, diverted and treated.
22. State some economic benefits of rivers and lakes.
Answer: (i) Water from the rivers is a basic natural resource, essential for various human activities.
(ii) The river banks have attracted settlers from ancient times. These settlements have now become big cities.
(iii) Using rivers for irrigation, navigation, hydro-power generation is of special significance.
(iv) Rivers are very significant for countries like India where agriculture is the livelihood for a majority of the population.
(v) Lakes help to develop tourism and provide recreation. Rivers have been of fundamental importance throughout human history.
23. Discuss the significant differences between the Himalayan and the Peninsular rivers.
Answer: Himalayan rivers:
(i) These rivers are perennial, i.e., they flow throughout the year.
(ii) They receive water from the melting of the glaciers, as well as rains.
(iii) They have long and deep courses.
(iv) They perform erosional activity in their upper course and carry huge loads of silt and sand.
(v) They have large drainage basins.
(vi) They make huge deltas at their mouths, which are well developed. Examples: Ganga and Brahmaputra
Peninsular rivers:
(i) These rivers are seasonal, i.e., they flow for a certain period in a year.
(ii) They depend mainly on the rains and dry up during the dry season.
(iii) They have short and shallow courses.
(iv) They carry less or no silt and sand during their course.
(v) They have comparatively smaller drainage basins.
(vi) They make smaller deltas and two of the rivers also make estuaries. Examples: Godavari and Narmada
24. Compare the East flowing and West flowing rivers of the Peninsular plateau.
Answer: The East flowing rivers:
(i) These rivers originate from the Western Ghats and flow eastwards.
(ii) They all form deltas at their mouths.
(iii) They drain into the Bay of Bengal.
(iv) They have large volume of water. Examples: Mahanadi, Godavari, Krishna and Kaveri
The West flowing rivers:
(i) These rivers originate in Central India and flow westwards.
(ii) They form estuaries since they flow from rift valleys.
(iii) They drain into the Arabian Sea.
(iv) They have lesser volume of water. Examples: Narmada and Tapi
25. Define the following drainage patterns: Dendritic, Trellis, Rectangular and Radial.
Answer:(i) Dendritic: The dendritic pattern develops where the river channel follows the slope of the terrain. The stream with its tributaries resembles the branches of a tree.
(ii) Trellis: A river joined by its tributaries at approximately right angles develops a trellis pattern. A trellis drainage pattern develops where hard and soft rocks exist parallel to each other.
(iii) Rectangular: A rectangular drainage pattern develops on a strongly joined rocky terrain.
(iv) Radial: A radial pattern develops when streams flow in different directions from a central peak or dome like structure.
26. What are the main causes of pollution of Indian rivers?
Answer: The main causes of pollution of Indian rivers are:
(i) The growing domestic, municipal, industrial and agricultural demand for water from rivers naturally affects the quality of water.
(ii) As a result, more and more water is drained out of the rivers, thereby reducing their volume.
(iii) A heavy load of untreated sewage and industrial effluents are emptied into the rivers. (iv) This affects not only the quality of water but also the self-cleansing capacity of the river.
(v) The increasing urbanisation and industrialisation has increased the pollution levels of the rivers.
27. What types of lakes are found in India? Give suitable examples.
Answer: India has many lakes. They differ in size and other characteristics. Most lakes are permanent, whereas some contain water only during the rainy season. There are lakes which are formed by the action of glaciers and ice sheets, while the others have been formed by human activities.
(i) Salt water lakes: Spit and bars form lagoons or salt water lakes in the coastal areas like the Chilika lake, Pulicat lake and the Kolleru lake. Sometimes salt water lakes are formed with island drainage like Sambhar lake in Rajasthan. Its water is used for producing salt.
(ii) Freshwater lakes: Most of these are in the Himalayan region. They are of glacier origin. They are formed when glaciers dug out a basin, which was later filled with snow melt. The Wular lake in Jammu and Kashmir is the largest freshwater lake in India. Other freshwater lakes are the Dal, Bhimtal, Nainital, Loktak and Barapani.
(iii) Man-made lakes: The damming of the rivers for the generation of hydel power has also led to the formation of lakes. These lakes are formed to drain excessive water of the river during floods and adding water to the rivers during the dry season. Such lakes are the Guru Gobind Sagar (Bhakra Nangal Project), Nizam Sagar, Nagarjuna Sagar, Rana Pratap Sagar, etc.
28. What are the benefits of lakes to human beings?
Answer: The benefits of lakes to human beings are:
(i) A lake helps to regulate the flow of a river.
(ii) During heavy rainfall, it prevents flooding and during the dry season, it helps to maintain an even flow of water.
(iii) Lakes can be used for developing hydel power too.
(iv) They help in maintaining a moderate climate.
(v) They are able to maintain the aquatic ecosystem.
(vi) They enhance the natural beauty and help in developing tourism and provide recreation.
29. Give characteristics of the Ganga-Brahmaputra River System.
Answer: The basin is separated from the Indus by the watershed in Haryana, i.e., Ambala. It covers the Central and the Eastern parts of the northern alluvial plains in Haryana, U.R, West Bengal and Assam. Its large central part is drained by river Ganga and its many tributaries. The general slope of the Ganga plain is from the north-west to south-east and south into Bay of Bengal. Its eastern part is drained by the mighty Brahmaputra river. It slopes from the north-east to south-west and then southward into Bangladesh.
30. Write main features of Indus Basin.
Answer: (i) The river Indus rises in Tibet, near lake Mansarovar.
(ii) Flowing west, it enters India in the Ladakh district of Jammu &: Kashmir. It forms a picturesque gorge in this part.
(iii) It flows through Baltistan and Gilgit and emerges from the mountain at Attock.
(iv) All its major tributaries?the Satluj, the Beas, the Ravi, the Chenab and the Jhelum join together to enter the Indus near Mithankot in Pakistan.
(v) Beyond this, the Indus flows southwards eventually reaching the Arabian Sea, east of Karachi. Indus is 2,900-km long and is one of the longest rivers of the world.
31. Give main characteristics of the Ganga River System.
Answer: (i) The headquarters of the Ganga called the ‘Bhagirathi’ is fed by the Gangotri Glacier and joined by Alkananda at Devaprayag in Uttarakhand.
(ii) At Haridwar the Ganga emerges from the mountains on to the plains.
(iii) Its tributaries flood parts of the northern plains every year, causing widespread damage to life and property but enriching the soil for the extensive agricultural lands.
(iv) Enlarged with the waters from its right and left bank tributaries, the Ganga flows eastward till Farakka in West Bengal. This is the northern most point of Ganga Delta.
(v) The mainstream flows southwards into Bangladesh and is joined by the Brahmaputra. This mighty river along with Brahmaputra flows into the Bay of Bengal and the delta formed by these rivers is known as Sunderban delta.
32. What are the main characteristics of the mighty river Brahmaputra?
Answer: (i) The Brahmaputra rises in Tibet east of Mansarovar Lake very close to the sources of the Indus and the Satluj.
(ii) It is slightly longer than the Indus and most of its course lies outside India.
(iii) In Tibet, the river carries a smaller volume of water and less silt as it is a cold and a dry area. (iv) In India, it passes through a region of high rainfall. Here the river carries a large volume of water and considerable amount of silt.
(v) The Brahmaputra has a braided channel in its entire length in Assam and forms many riverine islands.
(vi) Every year during the rainy season, the river overflows its banks causing widespread devastation due to floods in Assam and Bangladesh.
(vii) Unlike other north Indian rivers, the Brahmaputra is marked by huge deposits of silt on its bed causing the river bed to rise. The river also shifts its channel frequently.
33. Write down the differences between a delta and an estuary.
Answer: Delta
(i) It is a triangular-shaped piece of land formed at the mouth of a river, where it meets the sea.
(ii) With the continuous deposition of silt on its bed, a river goes on splitting itself into channels or distributaries. They carry river water into the sea.
(iii) Delta shows an extension of land into sea. It is continuously growing seawards.
(iv) The sea is shallow. Tidal currents are not strong enough to remove deposits effectively. (v) The world’s largest and the fastest growing delta is the Ganga- Brahmaputra delta known as the Sunderban delta. Peninsular rivers like the Mahanadi, Godavari, Krishna and Kaveri also form big deltas.
Estuary
(i) An estuary is an inlet formed generally by the submergence of the mouth of a river.
(ii) It has a single mouth or channel. It has steep banks or slopes. Where an estuary is formed, sea is deep.
(iii) Strong tidal waves carry away the little amount of sediments deposited by a river.
(iv) Estuaries produce an indented coastline and provide sites of natural harbours. They create conditions for better navigation.
(v) The mouths of rivers Narmada and Tapi present good examples of estuaries.
34. Give main characteristics of the largest peninsular river.
Answer: (i) The Godavari is the largest peninsular river.
(ii) Its length is about 1500 km. Its drainage basin is also the largest amongst the peninsular rivers.
(iii) The basin covers parts of Maharashtra, Madhya Pradesh, Odisha and Andhra Pradesh. (iv) The Godavari is joined by a number of tributaries such as the Purna, the Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga.
(v) The last three tributaries are very large. Because of its length and the area it covers, it is also known as ‘Dakshin Ganga’.
35. How Indian lakes differ from each other?
Answer: India has many lakes. These differ from each other in size, and other characteristics. Most lakes are permanent; some contain water only during the rainy season, like the lakes in the basins of inland drainage of semi-arid region. There are some of the lakes which are the result of the action of glaciers and ice sheets, while the others have been formed by wind, river action and human activities.
36. Describe the journey of river Ganga in India and which rivers join it en route.
Answer: (i) The river Ganga originates from Gangotri Glacier and is called Bhagirathi over here.
(ii) It is joined by Alaknanda at Devaprayag in Uttarakhand.
(iii) At Haridwar, it enters the plains and starts doing the job of transportation and deposition,
(iv) The major Himalayan rivers joining Ganga are the Yamuna, the Ghaghra, the Gandak and the Kosi.
(v) The river Yamuna flows parallel to the Ganga and as a right bank tributary meets the Ganga at Allahabad,
(vi) The Ghaghra, the Gandak and the Kosi originate from Nepal Himalayas and ultimately join river Ganga.
(vii) These rivers flood northern plains almost every year causing widespread damage to life and property but enriching the soil for the extensive agricultural land.
(viii) The tributaries coming from the peninsular uplands are the Chambal, the Betwa and the Son.
(ix) Enlarged with waters from its right and left bank tributaries, the Ganga flows eastwards till Farakka in West Bengal. This is the northern most point of the Ganga Delta. (x) The river bifurcates here; the Bhagirathi?Hooghly flows southwards through the deltic plains to the Bay of Bengal. With Brahmaputra, it forms the world’s biggest delta called the ‘Sunderbans Delta’. Here, ends the journey of river Ganga.
37. Have you heard about’Dakshin Ganga’? Give an account of its course.
Answer: (i) River Godawari is called the ‘Dakshin Ganga’.
(ii) It is the largest peninsular river.
(iii) It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra.
(iv) It is about 1,500 kms long and drains into the Bay of Bengal.
(v) Its drainage basin is the largest among other peninsular rivers.
(vi) The basin covers parts of Maharashtra, Madhya Pradesh, Odisha and Andhra Pradesh. (vii) The Godawari is joined by a number of tributaries like the Puma and Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga.
(viii) Because of its length and the area it covers, it is known as ‘Dakshin Ganga.’
38. Define the role of rivers in Indian economy.
Answer: (i) Rivers have been of fundamental importance throughout the human history.
(ii) Water from the rivers is a basic natural resource, essential for various human activities.
(iii) Therefore, the river banks have attracted settlers from ancient times. These settlements have now become big cities.
(iv) Using rivers for irrigation, navigation, hydro-power generation is of special significance particularly to a country like India, where agriculture is the major source of livelihood of the majority of its population.
39. What are the main causes of the pollution in the rivers of India? How can we prevent this kind of pollution?
Answer: (i) The growing domestic, municipal industrial and agricultural demand for water from rivers naturally affects the quality of water.
(ii) As a result, more and more water is being drained out of the rivers, reducing their volume.
(iii) On the other hand, a heavy load of untreated sewage and industrial effluents are emptied into the rivers.
(iv) This affects not only the quality of water but also the self-cleansing capacity of the rivers.
(v) But the increasing urbanisation and industrialisation do not allow it to happen and the pollution level of many rivers has been rising.
How to prevent pollution:
(i) The effluents of the industries should be treated before they enter the river waters.
(ii) People of the urban areas living on the banks of the rivers should be sensitised about the pollution levels of the rivers and the difficulty in cleaning it.
(iii) Since Indians are religious-minded and most of their festivals are associated with pure water of rivers, the immersing of deities, and of religious goods and even the dead are associated with these holy rivers, resulting into pollution, which needs to be checked and controlled.