Question 2:
Answer the following questions briefly,
(i). What is meant by the water divide? Give an example.
Answer:
Any elevated area, such as a mountain or upland, separates two drainage basins. Such upland is known as the water divide. Ambala is located on the water divide between the Indus and the Ganga river systems.
(ii). Which is the largest river basin in India?
Answer:
The Ganga basin is the largest basin in India.
(iii). Where do the rivers Indus and Ganga have their origin?
Answer:
- The headwaters of the Ganga called the ‘Bhagirathi’ is fed by the Gangotri Glacier and joined by the Alaknanda at Devprayag in Uttarakhand.
- At Haridwar, the Ganga emerges from the mountains on to the plains.
- The Indus flows through Baltistan and Gilgit and emerges from the mountains at Attock.
(iv). Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
Answer:
Alakananda and Bhagirathi are the two headstreams of the Ganga. They meet at Devprayag.
(v). Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
Answer:
The Brahmaputra river, which is known as Tsangpo in Tibet, receives a very little volume of water in Tibet so it has less silt there. On the other hand, this very river when enters India it passes through such a region which receives heavy rainfall. As such in India, it carries a large volume of water and a larger amount of silt.
(vi). Which two Peninsular rivers flow through trough?
Answer:
Narmada and Tapi are the two Peninsular rivers, which flow through the trough.
(vii). State some economic benefits of rivers and lakes.
Answer:
- Lake can be used for generating hydroelectricity.
- A lake can be a good tourist attraction.
- Rivers have been the centre of human civilization since ancient times.
- Even today, many big cities are situated on the bank of a river.
- River water is used for irrigation, navigation, hydroelectricity, fisheries, etc
Q4. Discuss the significant difference between the Himalayan and the Peninsular rivers.
Answer:
The Himalayan Rivers The Peninsular or Deccan Rivers
| Depend on rain and melted snow as well for water | Depend majorly on rainfall |
| The Main source of water is glaciers from the Himalayan range | The Main source is the Peninsular Plateau and the central highland |
| These rivers are perennial and have water throughout the year. | These are seasonal rivers. |
| Indus and Brahmaputra are two major rivers. | Godavari (Longest river in Peninsular ) and Narmada are the two main river systems. |
| Large river basin | Comparatively smaller river basin |
Q5. Compare the east-flowing and the west-flowing rivers of the Peninsular plateau.
Answer:
| East Flowing Rivers: | West Flowing Rivers: |
| These rivers drain in the bay of Bengal. | These rivers drain in the Arabian sea. |
| These rivers make deltas in their mouth. | These rivers enter the sea through eastuaries. |
| These rivers have a developed tributary system. Their tributaries are comparatively large in size. | These rivers are devoid of developed tributary system. Their tributaries are small in size. |
| These rivers flows through not very deep channels. | These rivers flow in a trough are a funnel like narrow but deep channels. |
| The Mahanadi , the Godavari , the Krishna, the Kaveri are the main east flowing rivers. | The Narmada and Tapi are main west flowing rivers. |
Q6. Why are rivers important for the country’s economy?
Answer:
- The rivers are important in country’s economy because human civilizations, were born in the river valleys, flourished and developed.
- They carry sediments and minerals which are very useful for us.
- Rivers provide cheap and efficient inland transport for trade and commerce.
- They help cities and towns to carry their wastes.
5. Their water is extensively used in irrigation and in developing hydroelectricity.
- The rivers contain natural fresh (sweet) water which is required for the survival of most of the animals including man.
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