Detailed, Step-by-Step NCERT Solutions for Class 11 Geography Chapter 3 Drainage System Questions and Answers were solved by Expert Teachers as per NCERT (CBSE) Book guidelines covering each topic in chapter to ensure complete preparation.
Drainage System NCERT Solutions for Class 11 Geography Chapter 3
Drainage System Questions and Answers Class 11 Geography Chapter 3
Question 1
Choose the right answer from the four alternatives given below :
i. Which one of the following rivers is known as the ‘Sorrow of Bengal’?
(a) The Gandak
(b) The Son
(c) The Kosi
(d) The Damodar
Answer:
(d) The Damodar
ii. Which one of the following rivers has the largest river basin in India?
(a) The Indus
(b) The Brahmaputra
(c) The Ganga
(d) The Krishna
Answer:
(a) The Indus.
iii. Which one of the following rivers is not included in ’ Panchnad ’ ?
(a) The Ravi
(b) The Chenab
(c) The Indus
(d) The Jhelum
Answer:
(c) The Indus
iv. Which one of the following rivers flows in the rift valley?
(a) The Son
(b) The Narmada
(c) The Yamuna
(d) The Luni
Answer:
(b) The Narmada
v. Which one of the following is the place of confluence of the Alkananda and the Bhagirathi?
(a) Vishnu Prayag
(b) Rudra Prayag
(c) Karan Prayag
(d) Deva Prayag
Answer:
(d) Deva Prayag
Question 2.
State the differences between the following :
(a) River Basin and Watershed
(b) Dendritic and Trellis drainage pattern
(c) Radial and Centripetal drainage pattern
(d) Delta and Estuary
Answer:
(a) River Basin and Watershed
| River Basin | Watershed |
| 1. The watersheds of large rivers are known as river basins. 2. It is marked by synergy and unity. |
1. It is an area drained by a river. 2. It is demarcated by a line that separates the watershed of one river from the adjoining one. |
(b) Dendritic and Trellis drainage pattern.
| Dendritic | Trellis |
| In dendritic pattern the drainage develops similar to the branches of a tree. | In this pattern, the primary tributaries flow more or less parallel to one another and secondary tributaries join from the side. |
(c) Radial and Centripetal drainage pattern
| Radial | Centripetal |
| 1. The rivers radiate from a hill. | 1. The rivers flow into a lake or a depression |
| 2. For example, Amarkantak plateau. | 2. For example, Sambhar lake in Rajasthan. |
(d) Delta and Estuary
| Delta | Estuary |
| 1. A delta is a triangular piece of alluvial lowland. 2. It is formed due to the deposition of sediment on the mouth of the river. |
1. The rivers which do not form delta form estuaries. 2. They do not deposit sediment on their mouth. This mouth is called estuary. |
Question 3.
Answer the following questions in about 30 words.
(a) What are the socio-economic advantages of inter-linking of rivers in India?
Answer:
The rivers of India carry huge volume of water approximately 2,124,3 7 cubic km. per year. But it is unevenly distributed both in time and space. One part has much water which is wasted in floods and one part of the country suffers from drought. To minimise this problem the surplus water is transferred to the deficit basin through inter-linking system.
(b) Write three characteristics of the Peninsular rivers.
Answer:
(i) Subsidence of the western flank of the Peninsula led to its submergence below the sea during the early tertiatry period. Generally, it has disturbed the symmetrical plan of the river on either side of the original watershed.
(ii) Upheaval of the Himalayas when the northern flank of the Peninsular block was subjected to subsidence and the consequent trough faulting. The Narmada and the Tapi flow in trough faults and fill the original cracks with their detritus materials. Hence, there is a lack of alluvial and deltaic deposits in these rivers.
(iii) Slight tilting of the Peninsular block from north-west to the south-eastern direction gave orientation to the entire drainage system towards the Bay of Bengal during the same period.
Question 4.
Answer the following questions in not more than 125 words.
(i) What are the important characteristic features of the north Indian rivers? How are these different from the peninsular rivers?
Answer:
The Brahmaputra, the Ganga and the Indus are the north Indian rivers. Gangarises in the Gangotri glacier in Uttrakashi district of Uttranchal. Uttar Pradesh, Bihar and West Bengal are other states drained by this river. The river finally discharges itself into the Bay of Bengal.
The Brahmaputra and the Indus originate on the southern slopes ofthe Tibetan highlands. These rivers run parallel to the axis of the Himalayas and take sudden turn towards the south cutting deep gorges in the mountain ranges to reach the great plain.
Important characteristics:
- North Indian rivers are perennial.
- Their regimes are dependent on the water supply from snow melt and rainfall.
- The catchment area of the north Indian river system is very large and extensive.
- The ‘Himalayan rivers flow into the deep gorges in the mountainous region and form meandering in the plains.
North Indian rivers are different from the peninsular river systems. The catchment area of the peninsular river systems is comparatively smatl and spreads over a limited area. These rivers are non-perennial. They are seasonal and rainfed. These rivers show little meandering and they have lesser erosional capacity.
(ii) Suppose you are travelling from Hardwar to Siliguri along the foothills of the Himalayas. Name the important rivers you will come across. Describe the characteristics of any one of them.
Answer:
Important rivers :
- Brahmaputra
- Siang or Dihang,
- Dibang or Sikang
- Lohit
- Subansiri
- Kameng
- Manas and Sankosh.
The Brahmaputra – The Brahmaputra system is an extensive and important river system of India. It spreads over 5,50,000 km2 area. It has its origin in the trans-Himalayan glacier of the Kailash range near Mansarovar Lake. The river emerges from the foothills under the name ofSiangandthen Dihang. Itenters India west of Sadiya town in Arunachal Pradesh. Flowing south-west, it receives its main left bank tributaries viz. Dibang and Lohit.
The Brahmaputra receives numerous tributaries in its 750 km. long journey in the Assam valley. The major tributaries are Burhi Dihang, Dhansari and Kalang on left bank and Subansari, Manas and Sankosh on right bank. After traversing a total length of about 2900 km. in Tibet, India and Bangladesh, it finally discharges in the Bay of Bengal after merging with the Padma river in Bangladesh.
Flood is a characteristic feature of Brahmaputra. This is due to the fact that both Purvanchal (eastern) Himalayas and Shillong plateau receive heavy rainfall.