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.

Question1: What is the drainage system?

Answer- The flow system of rivers flowing in an area and the various changes and characteristics resulting from it is called drainage system.

Question2: What is the drainage basin?

Answer- The area through which water flows through a river system is called a drainage basin.

Question3: What is a water separator?
Answer- The process of separating the runoff of two rivers from each other is called water divide.

Question4: Which country has the largest drainage basin in the world?

Answer- The world's largest drainage basin is the Nile river of Egypt.

Question5: What is the dendritic flow mode?

Answer- When a river along with its tributary cuts the surface of the land in a shape resembling the branches of a tree, then it is called diamorphic flow.

Question6: What is a rectangular flow pattern?

Answer- Rectangular flow pattern is formed when the river flows through an area of ​​hard rocks.

Question7: Into which two main categories are Indian rivers divided?

Answer-

1. Himalayan Rivers

2. Peninsular Rivers.

Question8: Which two main rivers of the Himalayas originate from the northern part of the mountain range?

Answer – Indus and Brahmaputra.

Question9: What are the different stages of the river?

Answer-

1. Delta

2. Wirsp

3. Gokhur Lake

4. Source of river

5. Upper part

6. Middle part

7. Lower part.

Question10: Name the major rivers that originate from the Himalayas?

Answer –

1 Indus

2 Ganga

3 Brahmaputra.
Question11: Which is the largest river basin in India?

Answer – Ganges river basin.

Question12: What is a river system?

Answer- A river and its major tributaries are called Tantra.

Question13: Write the length and origin of Indus river?

Answer- The length of the Indus river (2900) km and the origin of the Indus river is in Tibet near Mansarovar lake.

Question14: Describe the Indus Water Treaty?

Answer- According to the Articles of the Indus Water Treaty (1960), India can use only 20 percent of the entire water of this river process.

Question15: Name the two main streams of Ganga?

Answer- The names of two main streams of Ganga are :-

(i) Bhagirathi and (ii) Alaknanda.

Question16: Name the major tributaries of Ganga?

Answer-

1 Yamuna

2 Ghaghra

3 Gandak

4 Kosi.

Question17: By what name Ganga is called in Bangladesh?

Answer – Jamuna River.

Question18: By what name the river Ganga is called in the Sundarbans delta ?

Answer – Meghna River.

Question19: Name the world's largest delta?

Answer – Sundarban Delta.

Question20: What is the length of the Ganges, Brahmaputra, Indus, Narmada, Tapi, Godavari, Mahanadi, Krishna and Kaveri rivers?

Answer: Ganga (2500) km, Brahmaputra (2900) km, Indus (2900 km), Narmada (1300) km, Tapi (792) km, Godavari (1500) km, Mahanadi (855), Krishna (1400) km and Kaveri (765) Kilometers |

Question21: By which name the Brahmaputra river is known as in Arunachal Pradesh?

Answer: Dihang

Question22: Name the tributaries of Brahmaputra?

Answer: Dibang, Lohit, Kenula, Tista and Tosi.

Question23: What is the Brahmaputra called in Tibet and in Bangladesh?

Answer: Brahmaputra is called Jamuna in Tibet and Jamuna in Bangladesh.

Question24: Write the origin of Brahmaputra, Narmada, Tapi, Godavari, Mahanadi, Krishna and Kaveri?

Answer:

Brahmaputra:- This river originates from the east of Lake Mansarovar in Tibet and very close to the sources of Indus and Sutlej.

Narmada :- The origin of Narmada is in the Satpura range of Betle district in Madhya Pradesh.

Godavari :- Godavari rises from the slopes of Western Ghats in Nasir district of Maharashtra.

Mahanadi :- Mahanadi has its origin from the high land of Chhattisgarh.

Kaveri :- Kaveri originates from the Brahagiri range of West Ghat.

Question25: Which river forms the second largest waterfall in India?

Answer: Kaveri River.

Question26: Write the economic importance of lakes?

Answer: Lakes are very beneficial for humans. Its description is as follows:-

1. It prevents floods during extreme years.

2. Lakes are used to generate hydroelectricity.

3. It normalizes the climate of the surrounding areas.

4. Also keeps the aquatic ecosystem balanced.

5. Natural beauty of lakes and enhances tourism.

Question27: In terms of power to hydroelectric resources, which is the position of India in the world?

Answer: Fifth place

Question28: Describe the National River Conservation Plan?

Answer: The first phase of Ganga work was started in 1985. And it was closed on 31 March 2000. This scheme is now expanding to 152 areas located on the banks of 27 rivers flowing between 16 states. Out of total 215 schemes to reduce pollution, out of 69 schemes, so far have been completed. The main objective of this scheme is to reduce the increasing pollution in the rivers.

Question29: Give four differences between the rivers originating in the Himalayas and those originating from the peninsular plateau.

Answer: 

Rivers originating in the Himalayas

1. These rivers are endowed with snow and rain water. That is why she is called Sadanira.

2. All these rivers flow on the plains, they are used extensively in the last nine operations and irrigation.

3. These rivers are young and fast flowing.

4. There are many bifurcations and tributaries of these rivers.

  Rivers originating from the peninsular plateau

1. These rivers get water only from water for years. It dries up in summer and winter.

2. These rivers flow on plateau land where nine operations are not possible.

3. These rivers are very old and speedless.

4. The bifurcations of these rivers are in negligible number.