Q. 1. Name the two drainage systems of India.
Ans. Himalayan Rivers and Peninsular Rivers.
Q. 2. What is the total catchment area of the River Indus?
Ans. 1,165,000 sq. km.
Q. 3. Name two Indian rivers flowing through faults.
Ans. Narmada and Tapti.
Q. 4. Name the main watershed of Peninsular rivers.
Ans. The Western Ghats.
Q. 5. Name the water divide between the Rivers of Northern India and the Peninsular Rivers.
Ans. Vindhya—Satpura range.
Q. 6. Name the source of River Indus.
Ans. Mansarovar lake (Tibet).
Q. 7. What is the total length of the River Indus?
Ans. 2900 km.
Q. 8. Name the tributary of the Ganges which flows from South to North.
Ans. Son River.
Q. 9. Name a trans-Himalayan river that is the tributary of the Indus.
Q. 10. Name the rivers of the Indian plateau which flow towards the Arabian Sea.
Ans. Narmada and Tapti.
Q. 11. Name an important river of Peninsular India forming an estuary at its mouth.
Q. 12. Name the longest river of Peninsular India.
Q. 13. Name the source of the Krishna River.
Q. 14. What is the total catchment area of the Ganges in India?
Ans. 8,61,404 sq. km.
Q. 15. What name does river Ganga acquire in Bangladesh?
Ans. The Padma.
Q. 16. Name three rivers forming the Himalayas river system.
Ans. Indus, Ganga and Brahmaputra.
Q. 17. Name the rivers of Peninsular India falling into the Bay of Bengal.
Ans. Mahanadi, Godavari, Krishna and Kaveri.
Q. 18. Name a trans-Himalayan river.
Q. 19. Name a river of antecedent drainge.
Q. 20. In ancient times, which mighty river from Punjab to Assam flowed?
Ans. Indo-Brahm River.
Q. 21. What is the source of the Jhelum River?
Ans. Wular lake.
Q. 22. Name the delta formed by the Ganges River.
Q. 23. Which River is called Tsangpo in Tibet?
Ans. The Brahmaputra.
Q. 24. Which river is called ‘Dakshin Ganga’?
Ans. Godavari River.
Q. 25. Which waterfall is formed by the Narmada river near Jabalpur?
Ans. Marble Rocks.
Q. 26. Name the three main Himalayan river systems.
Ans. The Himalayan rivers consist of three main systems :
(i) The Indus System
(ii) The Ganges System
(iii) The Brahmputra System.
Q. 27. What is Gorge? Give two examples.
Ans. A gorge is a narrow, deep valley with steep (vertical) sides. Its bank continues rising, while its bed is deepened due to down cutting of the river. Many deep Gorges are found in the Himalayas such as Indus Gorge, Sutlej, Dihang Gorge (Brahmputra).
Q. 28. Where does the river Indus rise? Name its five important tributaries.
Ans. The river Indus rises in Tibet at an altitude of 5180 metres near Mansarovar lake. It is a trans-Himalayan river. It flows west and North-West-wards and reaches the Arabian sea. Its five important tributaries are the Jhelum, the Chenab, the Ravi, the Beas and the Sutlej.
Q. 29. Name two headstreams of the Ganga which unite at Dev-Prayag.
Ans. The Ganga rises in the U.P. from the Himalayas.
The two headstreams Alaknanda and Bhagirathi unite at Dev Prayag and the river gets its name as Ganga.
Q. 30. Name the major rivers of Peninsular India.
Ans. Some rivers of Peninsular India flow eastward into the Bay of Bengal. These are Mahanadi, Godavari, Krishna and Kaveri. Some rivers flow westward into the Arabian sea. These rivers include Narmada and Tapti.
Q. 31. What is delta? Give four examples from India.
Ans. A delta is a triangular piece of alluvial lowland formed at the mouth of the river.
It is formed due to deposition by the river at its lower course. Four examples of Deltas in India are :
(i) Ganges-Brahmputra Delta.
(ii) Mahanadi Delta.
(iii) Krishna Delta.
(iv) Kaveri Delta.
Q. 32. Why is the Godawari river often referred to as ‘Dakshina Ganga’ or Vridha Ganga?
Ans. The Godavari is the longest of the Peninsular rivers. It has an extensive drainage basin covering 3,12,812 sq. km. Its drainage basin extends through Maharashtra, Madhya Pradesh, Karnataka, Odisha and Andhra Pradesh. Because of its large size and extent, it is compared to river Ganga. It has got the same cultural significance in peninsular India as the Ganges has in the northern plain. Therefore it is referred to as Dakshina Ganga or Vridha Ganga.
Q. 33. Why do the rivers have no deltas on the Western Coast, even though they transport a lot of sediments with them?
Ans. The Narmada and Tapti are the main rivers flowing westward on the western coast. These rivers carry a large number of sediments with them. But these rivers do not form any delta near their mouths. These rivers form estuaries.
Unfavourable Conditions. The west coasts are not marked with favourable conditions required for the formation of a delta.
(i) The lower courses of these rivers have steep slopes.
(ii) The rivers have a swift current.
(iii) The rivers are unable to deposit their sediments at their mouths.
(iv) These rivers do not have any large tributaries to add to their sediments.
(v) These rivers flow through rift valleys.
Q. 34. Explain briefly the theory of the ‘‘IndoBrahm River’’ as believed by some geologists. Also mention the two principal grounds on which this theory has been discarded.
Ans. The Indo-Brahm River Theory. The Indus, the Ganga and Brahmputra river systems have been evolved over a long course of time. These rivers rise in Tibet i.e. in trans Himalayas. These rivers flow parallel to the main axis of the Himalayas. These rivers are older than the Himalayas themselves. Some of the geologists believe that before the uplift of the Himalayas, a mighty stream flowed from Assam to Punjab, all along the foot of the Himalayas. The stream is referred to as ‘Shiwalik’ or the ‘Indo-Brahm River’.
Due to the uplift of the Potwar Plateau, the direction of this river was reversed. The river was dismembered into three river systems of Indus, Ganga and Brahmputra. The Yamuna began to flow as a tributary of the Ganga. Due to headward erosion, the Ganga took a southerly course. Criticism. The concept of the Indo-Brahm river has been challenged on many grounds, even then the theory cannot be discarded.
(i) It is not necessary to visualize such a mighty stream to explain the alluvial deposits of Shiwaliks. These might have been formed by alluvial fans.
(ii) The alluvial deposits between Rajmahal Hills and Shillong plateaus should have been laid down over a much longer period.