NCERT Solutions Class 11 Geography Chapter 3: Drainage System
What is drainage?
Drainage refers to the system of rivers and streams that drain excess water from an area, ultimately leading to larger bodies of water like oceans, seas, or lakes.
What are the two main types of river systems in India?
The two main types of river systems in India are Himalayan rivers and Peninsular rivers.
How do Himalayan rivers differ from Peninsular rivers?
- Himalayan rivers are mostly perennial, meaning they flow throughout the year, while Peninsular rivers are mostly seasonal, dependent on rainfall.
- Himalayan rivers have long courses originating from high mountain ranges, whereas Peninsular rivers have shorter courses and flow towards the Bay of Bengal.
Can you name some major Himalayan rivers and their characteristics?
Major Himalayan rivers include the Indus, Ganga, and Brahmaputra. They have long courses, originate from the north of mountain ranges, and receive water from rainfall and melted snow.
What are some characteristics of Peninsular rivers?
Peninsular rivers flow eastwards and drain into the Bay of Bengal. They are mostly seasonal, originating from the Western Ghats, and form deltas at their mouths.
What are the important river basins in India?
Some important river basins in India include the Indus Basin, Ganga Basin, Brahmaputra Basin, Godavari Basin, Krishna Basin, and Kaveri Basin.
NCERT Solutions Class-11 Geography Chapter-3: Drainage System
NCERT Solutions for Class 11 Geography Chapter 3: Drainage System – This article includes free NCERT Solutions for Class 11 Geography Chapter 3: Drainage System to help students of Class 11 learn the solutions and ace their exams.
It has been developed by the subject matter experts at GFG, according to the latest CBSE Syllabus 2023-24, and guidelines to help the students of Class 11 create a solid conceptual base for Geography Chapter 3: Drainage System.
1. Choose the right answer from the four alternatives given below.
(i) Which one of the following rivers was 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:
(c) The Ganga
(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 a 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 Alaknanda and the Bhagirathi?
(a) Vishnu Prayag
(b) Rudra Prayag
(c) Karan Prayag
(d) Deva Prayag
Answer:
(d) Deva Prayag
2. State the differences between the following.
(i) River Basin and Watershed
| River Basin | Basis | Watershed |
|---|---|---|
| The catchments of large rivers are called river basins. | Meaning | Catchment of small rivulets and rills are often referred to as watersheds. |
| Rivers basins are larger in area. | Area | Watersheds are smaller in area. |
(ii) Dendritic and Trellis drainage pattern
| Dendritic drainage pattern | Trellis drainage pattern | |
|---|---|---|
| Dendritic drainage system is a drainage pattern resembling the branches of a tree is known as “dendritic”. | Basis | When the primary tributaries of rivers flow parallel to each other and secondary tributaries join them at right angles, the pattern is known as ‘trellis’. |
|
The drainage pattern of Northern plain is the example of such pattern. |
Meaning |
This pattern is found in Himalayan mountains and the Eastern ranges (Purvanchal). |
(iii) Radial and Centripetal drainage pattern
| Radical Drainage Pattern | Centripetal Drainage Pattern |
|---|---|
| When the rivers originate from a hill and flow in all directions, the drainage pattern is known as ‘radial’. | When the rivers discharge their waters from all directions in a lake or depression, the pattern is known as ‘centripetal’. |
| The rivers originating from the Amarkantak range is the example of such pattern. | Sambhar Lake of Rajasthan is the example of such pattern. |
(iv) Delta and Estuary
| Delta | Estuary |
|---|---|
| A Delta is a triangular landmass formed at the mouth of the river. | An Estuary is a funnel shaped formed at the mouth of the river. |
| It is formed in the regions of low tides and coastal plains. | It is formed in the regions of high tides and rift valleys. |
| These are extremely fertile and support agriculture. | They provide fishing ground and support inland transportation. |
| The rivers like Ganga and Brahmaputra form deltas. | The rivers like Narmada and Tapi form estuaries. |
3. Answer the following questions in about 30 words.
(i) What are the socio-economic advantages of inter-linking of rivers in India?
The socio-economic advantages of inter-linking of rivers in India are:
- The problems of floods and drought will get solved as excess water from an area can be transferred to water deficit areas.
- The inland waterway transportation will improve which will make the transportation of materials across the country easier.
- It will also help in imporving irrigational facilities which will increase the productivity.
- It will provide various opportunities such as hydro-electricity and fisheries activities.
(ii) Write three characterstics of the Peninsular river.
Three characteristics of the Peninsular river are:
- These rivers originate in Peninsular plateau and central highland.
- These are seasonal and dependent on monsoon rainfall.
- These rivers are smaller having fixed course with well adjusted valleys.
4. Answer the following questions in not more than 125 words.
(i) What are the important characteristic features of north Indian rivers? How are these different from Peninsular rivers?
Important characteristics of north Indian rivers are as follows:
- Origin: They originate in Himalayan mountain covered with glaciers.
- Nature of flow: These are perennial because they receive water from glacier and rainfall.
- Drainage pattern: These’ are antecedent and consequently lead to dendritic pattern in plains.
- Nature of river: It has long course, flowing through the rugged mountains experiencing headward erosion and river capturing; In plains it exhibits meandering and shifting of course.
- Catchment area: Its catchment areas include very large basins.
- Age of river: These rivers are young and youthful. These are active and deepening in the valleys.
These are different from peninsular rivers because these have following features:
- Place of origin: Peninsular plateau and central highland.
- Nature of flow: Seasonal as it is dependent on monsoon rainfall.
- Type of drainage: Super imposed, rejuvenated resulting in trellis, radial and rectangular patterns.
- Nature of river: Smaller, fixed course with well-adjusted valleys.
- Catchment area: Relatively smaller basin.
- Age of the river: Old rivers with graded profile, and have almost reached their base levels.
(ii) 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 any one of them.
While travelling from Haridwar to Siliguri along the foothills of the Himalayas, we shall come across Tons, Gomti, Saryu, Ramganga, Sharda, Gandak, Old Gandak, Kamla, Bagmati, Kosi and Ganga.
The Ganga is the most important river of India both from the point of view of its basin and cultural significance. It rises in the Gangotri glacier near Gaumukh which is 3,900 m high from sea level in the Uttarkashi district of Uttarakhand. It is known as the Bhagirathi in this region. At Devaprayag, the Bhagirathi meets the Alaknanda; hereafter, it is known as the Ganga. The Ganga enters the plains at Haridwar. From here, it flows first to the south, then to the south¬east and east before splitting into two distributaries, namely the Bhagirathi and the Hugli.
The river has a length of 2,525 km. It is shared by Uttarakhand (110 km) and Uttar Pradesh (1,450 km), Bihar (445 km) and West Bengal (520 km). The Ganga basin covers about 8.6 lakh sq. km area in India alone. The Ganga river system is the largest in India having a number of perennial and non-perennial rivers originating in the Himalayas in the north and the Peninsula in the south, respectively.
Yamuna joins the Ganga at Prayag (Allahabad). It is joined by the Chambal, the Sind, the Betwa and the Ken on its right bank which originates from the Peninsular plateau while the Hindan, the Rind, the Sengar, the Varuna, etc. join it on its left bank. Much of its water feeds the western and eastern Yamuna and the Agra canals for irrigation purposes.