ADDITIONAL QUESTIONS AND ANSWERS:
Answer the following questions :
1. What is a drainage basin ?
Ans: The area where all the streams and rivers culminate to form a single river is known as a drainage basin .
2. What is the work of a drainage basin ?
Ans: The drainage basin acts as a funnel; it collects water within the area covered by the basin and the channels it out to a single river .
3. What is a catchment area ?
Ans: The area within a drainage basin is known as the catchment area .
4. What is a water shed (water divide) ?
Ans: Each drainage basin is separated topographically from the adjacent basins by a geographical barrier such as a ridge, hill or a mountain. Such a geographical barrier is known as a water shed or a water divide .
5. What do you mean by a river system ?
Ans: A river system consists of a main river, along with its tributaries which drain into a large water body. The seven major rivers and their numerous tributaries form the Indian River system .
6. Name the four types of rivers divided on the basis on their origin .
Ans: Based on their origins they are broadly divided into four types – Himalayan Rivers, Coastal Rivers, Deccan Rivers and rivers of the inland drainage basin .
7. Write a note on Himalayan Rivers .
Ans: The Himalayan Rivers are perennial, as they get water from the monsoons as well as from the melting snow of the mountains. During the monsoon months, the Himalayas receive very heavy rainfall and rivers swell up causing frequent floods. The Himalayan rivers begin their long journey towards the sea from the steep slopes of the Himalayas. In this region they erode the valleys, carry huge amount of silt and sand (alluvium) which later get deposited in the lower reaches to form extensive plains. In the lower course they form meanders, oxbow lakes and many other depositional features. These rivers while meeting with the sea, develop huge deltas .
8. What is a delta ?
Ans: Delta is a landform formed at the mouth of a river where the river flows into an ocean, sea .
9. How is a delta formed ?
Ans: A delta is formed from the deposition of sediments carried by the river as the flow leaves the mouth of the river .
10. Write 4 sentences on:
(a) The Peninsular rivers. (b) The Coastal rivers .
Ans:
(a) The Peninsular Rivers :
They are non-perennial (seasonal) as they are rain fed. It is because of this factor that the volume of the water fluctuates. Even the larger rivers like Godavari , Kaveri , etc have a reduced flow in the non-monsoon seasons. These rivers are shorter and shallower than the Himalayan Rivers.
(b) The Coastal Rivers of the west coast :
They are non-perennial as they are rain fed. These rivers are short and swift with deep entrenched valleys. They have a small catchment area. They fuse with the Arabian Sea as estuaries. The streams of inland drainage basin of western Rajasthan are not only few in number but are of short lived nature as well. They run dry for most parts of the year .
11. The river Damodar is called as the “Sorrow of Bengal”. Why ?
Ans: The river Damodar is known as “Sorrow of Bengal” because of the severe threat it poses to the life and property of the people due to frequent floods and changes in the river course .
12. Which river is red in colour ? Why is it so ?
Ans: The Brahmaputra is also known as the red river of India. It’s red colour is due to the suspension of red soils of Assam .
13. What is the spectacular scene in the Brahmaputra river in the Tibetan region ?
Ans: Ferries and boats of bamboo and leather are in use at a height of 3658 m above msl. This is a spectacular scene in Brahmaputra River .
14. The Brahmaputra river in the Tibetan plateau carries less water. Why ?
Ans: This river carries very less water as the climate of the Tibetan plateau is cold and dry .
15. After the Brahmaputra river is joined by the Dihang it results in frequent shifting of the river channel. Why ?
Ans: The river tends to shift its flow in the channel owing to the huge amount of silt brought down by the river. This results in frequent shifting of the river channel .
16. Write a short note on rivers of Peninsular India .
Ans: The second major watershed is that of Peninsular India. It is formed by the Western Ghats. Peninsular India is drained by five major river systems. These include Mahanadi, Godavari, Krishna, Pennuru and Kaveri.
All these rivers flow eastwards and drain into the Bay of Bengal by forming deltas. Besides these rivers, the Peninsular India has two major rivers.
i.e. the Narmada and Tapi .
All these rivers join the sea through the estuaries. The rivers of Peninsular India are much smaller than the Himalayan Rivers .
17. Write 4 – 5 sentences on Sardar Sarovar Dam .
Ans: The Sardar Sarovar Dam is one of the largest water resource project of India covering the four states of Maharashtra, Madhya Pradesh, Gujarat and Rajasthan.
The construction of this project began in 1979 as a part of a development scheme to increase irrigation and produce hydroelectricity.
The Sardar Sarovar Dam is built near Navagam in Gujarat. Of the 30 dams planned on river Narmada, this is the largest structure to be built .
18. Write three main features on: (a) River Tapi (b) River Godavari .
Ans:
(a) River Tapi: The Tapti or Tapi River is yet another major river of Peninsular India. It is one of the only three rivers in peninsular India that flows from east to west. The principal tributaries of the Tapti River are the Purna, Girna, etc .
(b) River Godavari: The Godavari is a river that runs from the west to the south of India. It is the largest river of peninsular India. It flows over a distance 1465kms before it drains into the Bay of Bengal in Andhra Pradesh .
19. Write one main feature on the rivers (i) Mahanadi (ii) Krishna .
Ans:
(i) Mahanadi: It is a seasonal river and the longest dam in India(the Hirakund Dam) is built across the river Mahanadi .
(ii) Krishna: It is one of the longest rivers in the central-southern part of India .
20. Write the difference between the east flowing rivers and the west flowing rivers .
Ans:
| East flowing rivers | West flowing rivers |
| 1. The Mahanadi , the Godavari , the Krishna and Cauvery are the main east flowing rivers . | 1. The Narmada and the Tapi are the main west flowing rivers . |
| 2. These rivers drain into the Bay of Bengal . | 2. These drain into the Arabian Sea . |
| 3. These rivers make deltas at their mouth . | 3. These rivers enter the sea through estuaries . |
| 4. These rivers have a developed large tributary system | 4. Their tributaries are quite small in size . |
| 5. These rivers do not flow through very deep canals . | 5. These rivers flow through troughs . |
21. Give the ecological uses of rivers and lakes .
Ans: Rivers and lakes help regulate the flow of water, control floods during heavy rainfall and maintain an even flow of water during summer .
22. Give three economical uses of rivers and lakes .
Ans: The rivers and lakes are essential for agriculture and industry. They are also used for hydroelectric generation, inland navigation, tourism and recreation. They are also helpful for the fishing industries .
23. Write a short note on rivers of Goa .
Ans: There are two major and seven minor rivers flowing through the state of Goa. The main rivers are the Zuari, Mandovi, Tiracol, Chapora, Sal, Tapona and Galgibag. All these rivers originate from the Sayhadri ranges and flow westward into the Arabian Sea. These rivers are navigable throughout the year and have deep valleys cutting through the Sayhadris .
24. Write 3 sentences on these rivers:
(a) River Zuari (b) River Mandovi (c) Sal River.
Ans:
(a) River Zuari :
The Zuari is the largest river in the state. It is a tidal river. It originates from the Western Ghats. The river is also referred to as the Aghanashani in the interior regions.
(b) River Mandovi :
It is also known as the Mahadayi or Mhadei river. It is described as the lifeline of the state of Goa. It originates from a cluster of 30 springs at Bhimgad in the Western Ghats in the Belgavi district of Karnataka .
(c) Sal River :
This river flows through South Goa. Sal is the third largest river in Goa. Sal river is considered to have a geological and hydrological oddity as it is the only river that flows in the North- South direction before entering into the Arabian Sea at Betul .
25. Write two sentences on each of these rivers:
(a) Mapusa river (b) Galgibaga river (c) Terekhol river .
Ans:
(a) Mapusa River: The Mapusa river originates from the Jungles of Dumacem and Amthane. Since ancient times, the river has been used as a popular waterway to transport agricultural products and spices .
(b) Galgibaga River: This is the southern most river in Goa. It also flows through Canacona taluka and it drains into Arabian Sea .
(c) Terekhol River: The Terekhol River rises around Manohargad in the Western ghats of Maharashtra. The river forms the boundary between Maharashtra and Goa .
26. Which are the important lakes and springs found in Goa .
Ans: Mayem lake in BicholimTaluka, is an artificial lake located 35 kms from Panaji.
The Carambolim lake is a natural lake which is at a distance of 12 kms from Panaji whereas Curtorim lake is in the south of Goa.
Besides these lakes, there is a famous spring at Kesarval and a well known medicinal spring at Baga beach in Goa .
Match the columns:
Column A Column B
1) Indus a) Trimbakeswar hills
2) Ganga b) Mahabaleshwar
3) Yamuna c) Kailash range
4) Bramhaputra d) Amarkantak hills
5) Narmada e) Gangotri Glacier
6) Tapi f) Eastern Ghats (Chhattisgarh)
7) Godavari g) Yamnotri Glacier
8) Mahanadi h) Satpura Range
9) Krishna i) Brahmagiri range
10) Kaveri j) Angsi Glacier
Ans:
1 → c 2 → e 3→ g 4 → j 5 → d
6 → h 7→ a 8 → f 9 → b 10 → i .
Fill in the blanks :
1. The Coringa mangrove forests in the Godavari delta is the second largest in the country .
2. The three rivers Indus, Ganga, Brahmaputra form the Himalayan river system .
3. The Ghagra, Gandak, Kosi have their source in the Nepal Himalayas .
4. The left bank tributaries of the Ganga that originate from the peninsular uplands are the Chambal , Betwa and Son .
5. The Ganga is one of the longest rivers and flows over a distance of 2550 kms .
6. Farakka Barrage is a barrage across the Ganga in the state of West Bengal .
7. Peninsular India is drained by five major river systems, they include Mahanadi, Kaveri, Godavari, Krishna, and Pennuru .
8. The Sardar Sarovar Dam is one of the largest water resource project of India .
9. The Sardar Sarovar Dam covers the four states of Maharashtra , Madhya Pradesh, Gujarat, and Rajasthan .
10. The Godavari is also known as Dakshin Ganga .
11. Irwin bridge is one of the oldest, historic and largest bridges built on the river Krishna .
12. The waters of the Mandovi and Zuari flush out into the Arabian sea at a common point called Cabo Aguada .