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
Answer: (d) Jammu and Kashmir
(ii) The river Narmada has its source at
(a) Satpura
(b) Brahmagiri
(c) Amarkantak
(d) Slopes of the Western Ghats
Answer: (c) Amarkantak
(iii) Which one of the following lakes is a salt water lake?
(a) Sambhar
(b) Dal
(c) Wular
(d) Gobind Sagar
Answer: (a) Sambhar
(iv) Which one of the following is the longest river of the Peninsular India?
(a) Narmada
(b) Krishna
(c) Godavari
(d) Mahanadi
Answer: (c) Godavari
(v) Which one amongst the following rivers flows through a rift valley?
(a) Mahanadi
(b) Tungabhadra
(c) Krishna
(d) Tapi
Answer: (d) Tapi
Q2. Answer the following questions briefly.
(i) What is meant by a water divide? Give an example.
Answer: The water divide separates two neighboring drainage basins, such as the Western Ghats of peninsular India.
(ii) Which is the largest river basin in India?
Answer: The largest river basin in India is Ganga basin.
(iii) Where do the rivers Indus and Ganga have their origin?
Answer: Indus river originates in Tibet near Lake Mansarovar. The main stream of the Ganges "Bhagirathi" originates from the Gangotri glacier.
(iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
Answer: Bhagirathi and AlaknandaBoth of these meet at Devprayag in Uttarakhand.
(v) Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
Answer: In the region of Tibet, the Brahmaputra receives less water because Tibet is a cold and dry region. Therefore, the amount of water and silt (sand soil) in this river is very less here. On the contrary, in India, it passes through areas of high rainfall, so the amount of water and silt increases in it.
(vi) Which two Peninsular rivers flow through trough?
Answer: Narmada and Tapi rivers flow through the trough. They form estuaries before entering the sea.
(vii) State some economic benefits of rivers and lakes.
Answer:
Following are the economic importance of rivers and lakes:-
(i) Rivers and lakes are the source of income due to tourist attraction.
(ii) Irrigation comes from rivers and lakes, which encourages agriculture.
(iii) Rivers are the best means of navigation and water transport i.e. carrying goods etc.
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
Answer:
Natural Lakes:- Wular, Dal, Nainital, Bhimtal, Loktak, Barapani, Chilka, Sambhar, Pulicat.
Man-made lakes:- Gobind Sagar, Rana Pratap Sagar, Nizam Sagar, Nagarjuna Sagar, Hirakud
Q4. Discuss the significant differences between Himalayan and peninsular rivers.
Answer:
Himalayan Rivers
(i) Most of the Himalayan rivers are perennial. They hold water throughout the year, as they also get water from the melting snow from high mountains in addition to rain.
(ii) Two major Himalayan rivers Indus and Brahmaputra originate from the northern part of the Himalayas. These rivers cut the mountains to form Gorjo (Mahakhand).
(iii) In the middle and lower parts, these rivers form Visarpa, Gokhur Lake and many other depositional figures in their flood plains.
(iv) They form fully developed deltas.
Peninsular Rivers
(i) Most of the peninsular rivers are seasonal as their flow depends on the year. In dry season, the water of big rivers also decreases and starts flowing in small streams.
(ii) Peninsular rivers flow through less deep valleys.
(iii) Due to the hard rock bottom and lack of sand and silt, these rivers are not able to drain due to special deficiency. Therefore, the routes of many rivers are straight and linear.
(iv) Narmada and Tapi form estuaries while east flowing rivers form deltas near the estuaries.
Q5. Compare the east flowing and the west flowing rivers of the Peninsular plateau.
Answer:
| Rivers flowing east of the plateau | Rivers flowing west of the plateau |
| (i) Mahanadi, Godavari, Krishna and Kaveri flow east. | (i) Narmada and Tapi are the only two big rivers which flow towards west. |
| (ii) These rivers form deltas at their mouths. | (ii) These rivers form estuaries. |
| (iii) Their tributaries are large. | (iii) Their tributaries are short in length. |
Q6. Why are rivers important for the country’s economy?
Answer:
Rivers are important for the economy of a country because :-
(i) Water from rivers is a basic natural resource and is essential for many human activities. This is the reason that the banks of the rivers have attracted the tribals towards them since ancient times.
(ii) For a country like India, where most of the population is dependent on agriculture for livelihood, the importance of rivers in irrigation, navigation, hydropower generation is very high.
