Chapter 3: Drainage - NCERT Solutions
Exercises
Q1. Choose the right answer from the four alternatives given below.
(i) In which of the following states is the Wular lake located?
(a) Rajasthan
(b) Uttar Pradesh
(c) Punjab
(d) Jammu and Kashmir
(ii) The river Narmada has its source at
(a) Satpura
(b) Brahmagiri
(c) Amarkantak
(d) Slopes of the Western Ghats
(iii) Which one of the following lakes is a salt water lake?
(a) Sambhar
(b) Dal
(c) Wular
(d) Gobind Sagar
(iv) Which one of the following is the longest river of the Peninsular India?
(a) Narmada
(b) Krishna
(c) Godavari
(d) Mahanadi
(v) Which one amongst the following rivers flows through a rift valley?
(a) Mahanadi
(b) Tungabhadra
(c) Krishna
(d) Tapi
(i) In which of the following states is the Wular lake located?
(a) Rajasthan
(b) Uttar Pradesh
(c) Punjab
(d) Jammu and Kashmir
(ii) The river Narmada has its source at
(a) Satpura
(b) Brahmagiri
(c) Amarkantak
(d) Slopes of the Western Ghats
(iii) Which one of the following lakes is a salt water lake?
(a) Sambhar
(b) Dal
(c) Wular
(d) Gobind Sagar
(iv) Which one of the following is the longest river of the Peninsular India?
(a) Narmada
(b) Krishna
(c) Godavari
(d) Mahanadi
(v) Which one amongst the following rivers flows through a rift valley?
(a) Mahanadi
(b) Tungabhadra
(c) Krishna
(d) Tapi
Answer - (i) (d) Jammu and Kashmir
(ii) (c) Amarkantak
(iii) (a) Sambhar
(iv) (c) Godavari
(v) (d) Tapi
(ii) (c) Amarkantak
(iii) (a) Sambhar
(iv) (c) Godavari
(v) (d) Tapi
Q2. Answer the following questions briefly.
(i) What is meant by a water divide? Give an example.
(ii) Which is the largest river basin in India?
(iii) Where do the rivers Indus and Ganga have their origin?
(iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
(v) Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
(vi) Which two Peninsular rivers flow through trough?
(vii) State some economic benefits of rivers and lakes.
(i) What is meant by a water divide? Give an example.
(ii) Which is the largest river basin in India?
(iii) Where do the rivers Indus and Ganga have their origin?
(iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
(v) Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
(vi) Which two Peninsular rivers flow through trough?
(vii) State some economic benefits of rivers and lakes.
Answer - (i) A water divide is a geographical barrier, such as a mountain or ridge, that separates one drainage basin from another. Example: The Western Ghats act as a water divide.
(ii) The Ganga basin is the largest river basin in India.
(iii) The river Indus originates in Tibet near Lake Mansarovar, and the Ganga originates from the Gangotri Glacier in the Himalayas.
(iv) The two headstreams of the Ganga are Bhagirathi and Alaknanda. They meet at Devprayag to form the Ganga.
(v) The Brahmaputra carries less silt in Tibet because the region is dry and has a cold climate with little erosion.
(vi) The Narmada and Tapi rivers flow through troughs or rift valleys.
(vii) Economic benefits of rivers and lakes include: irrigation for agriculture, water for drinking and industries, generation of hydroelectricity, inland navigation, and fishing and tourism opportunities.
(ii) The Ganga basin is the largest river basin in India.
(iii) The river Indus originates in Tibet near Lake Mansarovar, and the Ganga originates from the Gangotri Glacier in the Himalayas.
(iv) The two headstreams of the Ganga are Bhagirathi and Alaknanda. They meet at Devprayag to form the Ganga.
(v) The Brahmaputra carries less silt in Tibet because the region is dry and has a cold climate with little erosion.
(vi) The Narmada and Tapi rivers flow through troughs or rift valleys.
(vii) Economic benefits of rivers and lakes include: irrigation for agriculture, water for drinking and industries, generation of hydroelectricity, inland navigation, and fishing and tourism opportunities.
Q3. Below are given names of a few lakes of India. Group them under two categories – natural and created by human beings.
(a) Wular
(b) Dal
(c) Nainital
(d) Bhimtal
(e) Gobind Sagar
(f) Loktak
(g) Barapani
(h) Chilika
(i) Sambhar
(j) Rana Pratap Sagar
(k) Nizam Sagar
(l) Pulicat
(m) Nagarjuna Sagar
(n) Hirakund
(a) Wular
(b) Dal
(c) Nainital
(d) Bhimtal
(e) Gobind Sagar
(f) Loktak
(g) Barapani
(h) Chilika
(i) Sambhar
(j) Rana Pratap Sagar
(k) Nizam Sagar
(l) Pulicat
(m) Nagarjuna Sagar
(n) Hirakund
Answer - Natural Lakes: Wular, Dal, Nainital, Bhimtal, Loktak, Barapani, Chilika, Sambhar, Pulicat
Man-made Lakes: Gobind Sagar, Rana Pratap Sagar, Nizam Sagar, Nagarjuna Sagar, Hirakund
Man-made Lakes: Gobind Sagar, Rana Pratap Sagar, Nizam Sagar, Nagarjuna Sagar, Hirakund
Q4. Discuss the significant difference between the Himalayan and the Peninsular rivers.
Answer -
| Himalayan Rivers | Peninsular Rivers |
|---|---|
| Perennial rivers – have water throughout the year. | Mostly seasonal – depend on rainfall. |
| Originate from the Himalayas and glaciers. | Originate from the Peninsular plateau and hills. |
| Longer courses and flow through plains and valleys. | Shorter courses and flow over uneven terrain. |
| Form meanders and have extensive floodplains. | Do not form meanders; have narrow and shallow valleys. |
| Important rivers: Ganga, Yamuna, Brahmaputra. | Important rivers: Narmada, Godavari, Krishna, Mahanadi. |
Q5. Compare the east flowing and the west flowing rivers of the Peninsular plateau.
Answer -
| East Flowing Rivers | West Flowing Rivers |
|---|---|
| Flow into the Bay of Bengal. | Flow into the Arabian Sea. |
| Form large deltas at their mouths. | Form estuaries at their mouths. |
| Include rivers like Godavari, Krishna, and Mahanadi. | Include rivers like Narmada and Tapi. |
| Have larger drainage basins. | Have relatively smaller drainage basins. |
| Flow over softer rocks and plains. | Flow through rift valleys and hard rocks. |
Q6. Why are rivers important for the country’s economy?
Answer - Rivers play a vital role in India’s economy due to the following reasons:
1. Irrigation – Rivers provide water for agricultural activities, especially in the plains.
2. Drinking Water and Domestic Use – They supply water for household and municipal needs.
3. Hydroelectric Power – Flowing water from rivers is harnessed to generate electricity.
4. Inland Transport – Rivers serve as inland waterways for transport and trade.
5. Tourism and Fishing – Rivers support fishing and attract tourists, boosting local economies.
1. Irrigation – Rivers provide water for agricultural activities, especially in the plains.
2. Drinking Water and Domestic Use – They supply water for household and municipal needs.
3. Hydroelectric Power – Flowing water from rivers is harnessed to generate electricity.
4. Inland Transport – Rivers serve as inland waterways for transport and trade.
5. Tourism and Fishing – Rivers support fishing and attract tourists, boosting local economies.