Drainage
Textbook Exercises
1.Choose the right answer from the four alternatives given bejow?
- (i) Which one of the following describes the drainage patterns resembling the branches of a tree
- (a) Radial
- (b) Dendritic
- (c) Centrifugal
- (d) Trellis
ans:
- (b) Dendritic
- (ii) In which of the following states is the Wular lake located
- (a) Rajasthan
- (b) Uttar Pradesh
- (c) Punjab
- (d) Jammu&Kashmir
ans:
- (d) Jammu&Kashmir
- (iii) The river Narmada has its source at
- Satpura
- Brahmagir
- Amarkantak
- Slopes of the Western Ghats
ans:
- Amarkantak
- (iv) Which one of the following lakes is a salt water lake
- Sambhar
- Dal
- Wular
- Gobind Sagar
ans:
- Sambhar
- (v) Which one of the following is the longest river of the Peninsular India
- Narmada
- Amravati
- Godavari
- Mahanadi
ans:
- Godavari
- (vi) Which among the following rivers flow through a rift valley
- Damodar
- Tungabhadra
- Krishna
- Tapi
ans:
2.Answer the following questions?
- (i) What is meant by a water divide? Give an example
ans:The upland that separates two drainage, basins is called the water divide
Examples
any elevated area, the mountain.
- (ii) Which is the largest river basin in India
ans:The Ganga Basin
- (iii) Where do the rivers Indus and the Ganga have their origin
ans:Mansarovar Lake
- (iv) Name the two headstreams of the Ganga. Where do they unite to form the Ganga
ans:The two headstreams Of tire Ganga are the Alaknanda and Bhagirathi. They unite at Devprayag to form the Ganga
- (v) Why does the Brahmaputra, in its Tibetan part have less silt, despite a longer course
ans:Despite a longer course, the Brahmaputra, in its Tibetan part have- less silt because it receives very little volume of water here
- (vi) Which two peninsular rivers flow through trough? What features do they form while entering the sea
ans:
- The Narmada and
- The Tapi are the two peninsular rivers which flow.through trough. On their way to the sea, they create many picturesque locations. The Marble rocks and the Dhualdhar falls constitute a remarkable feature
- (vii) State some economic benefits of rivers and lakes
ans:
The five economic benefits of rivers and lakes Can be stated as under:
- Water from lakes and rivers help develop hydel power
- They help develop tourism industry
- They help in providing irrigation for agriculture
- They provide water necessary for numan life
- For industries and their development, water becomes a raw material, example it provides coolants
3.Below are given names of a few lakes of India. Group them under two categories-natural and man-made
- Wular
- Dal
- Nainital
- Bhimtal
- Gobind Sagar
- Loktal
- Barapani
- Chilka
- Sambhar
- Rana Pratap Sagar
- Nizam Sagar
- Pulicat
- Nagariuna Sagar
- Hirakund
ans:Natural
Wular
Dal
Nainital
Bhiniial
Sambhar
Pulicat
Loktal
Chilka
Barapani
Man-made
- Gobind Sagar
- Rana Pratap Sagar
- Nizam Sagar
- Nagarjun Sagar
- Hirakud
4.Discuss die significant differences between die Himalayan and the Peninsular rivers?
ans:
| The Himalayan Rivers |
The Peninsular Rivers |
| These are the rivers which risein the snow-covered mountains as such they flow throughout the year |
These rivers rise from the mount-ains in the Deccan which are not snow covered |
| The Himalayan rivers flow in levelled Northern plains. Hence these are more useful in navigation and irrigation |
These rivers flow On uneven rocky surface. Hence these are not very suitable for navigation or irrigation |
| These rivers bring fertile alluvium with them |
These do not bring enough alluvium with them. The currents in these rivers are so swift that the deposition activity, is negligible |
| Canals can be easily dug to use the water of these rivers for irrigation |
The banks of these rivers are high and the terrain also rocky. Hence in these rivers canals cannot be dug |
5.Compare the east flowing and the west flowing rivers of the peninsular plateau
ans:
| East Flowing Rivers |
West flowing Rivers |
| The east flowing rivers move to-wards the east- direction |
The west flowing rivers move towards the west direction |
| The Mahanadi, the Godavari, the Krishna and the Kaveri are the east flowing rivers of the peninsular India while Yamuna and Ganga also move eastward in the northern India |
Narmada and Tapi are the important west flowing rivers of the Peninsular India. Indus is the west flowing river of northern India |
| These rivers fall in to the Bay of Bengal |
These rivers fall in the Arabian sea |
| Most of these rivers make deltas at their mouth |
These rivers enter the sea through estuaries |
| The east flowing rivers have a developed tribut-ary system. These tributaries are comparatively large in size |
The west flowing rivers are devoid of a developed tributary system. These tributaries are small in size |
| The east flowing rivers generally do not flow through very deep channels |
The west flowing rivers flow in throughout or a funnel like narrow but deep channels |
6.Why are rivers important for the countrys economy
ans:Rivers provide the most productive agricultural lands of the country. The Ganga, the Kaveri, and other deltas have traditionally been the rice growing areas. Irrigation from rivers has been the backbone of the development of Indian agriculture. Industrial development has flourished along rivers as many industrial processes rely on water as a raw material, as a coolant, and for the generation of hydro electricity. The rivers provide primary channels of inland transportation which are necessary for countrys economy