CLASS-9 DRAINAGE

Q1. Choose the right answer from the four alternatives given below.

i). Which one of the following describes the drainage patterns resembling the branches of a tree?

a) Radial

b) Dendritic 

c) Centrifugal

d) Trellis

ii) In which of the following states is the Wular lake located?

  1. Rajasthan
  2. B) Uttar Pradesh
  3. Punjab
  4. Jammu and Kashmir   

iii) The river Narmada has its source at-

  1. Satpura
  2. Brahmagiri
  3. Amarkantak
  4. Slopes of the western ghats

iv) Which one of the following lakes is a salt water lake?

  1. Sambhar
  2. Dal
  3. Wular
  4. Gobind Sagar

v) Which one of the following is the longest river of the peninsular India?

a) Narmada

b) Krishna

c) Godavari

d) Mahanadi

vi) Which one amongst the following rivers flows through a rift valley?

  1. Mahanadi
  2. Tungabhadra
  3. Krishna
  4. Tapi  

Q2. Answer the following question briefly.

i). What is meant by water divide? Give an example.

Ans. An elevated area such as mountain or an upland that separates two drainage basins is known as water divide.

Example- the water divide between the Indus and the Ganga . Ambala is situated on this water divide.

ii) Which is the largest river basin in India?

Ans. The Ganga river basin, 2500 Km.

iii). Where do the rivers Indus and Ganga have their origin?

Ans. Indus- Tibet near Mansarovar lake.

         Ganga- Gangotri glacier.

iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?

Ans. Bhagirathi and Alaknanda. They meet to form the Ganga at Devprayag in Uttrakhand.

v). Why does the Brahmaputra in its Tibetan part have less silt despite a longer course?

Ans. The Brahmaputra in its Tibetan part carries a smaller volume of water and less silt as it is a cold and a dry area.

vi). Which two peninsular rivers flow through trough?

Ans. Narmada and Tapi.

vii). State some economic benefits of rivers and lakes.

Ans.

  • They provide water which is a basic natural resource.
  • They moderate the climate of the surroundings and maintain the aquatic ecosystem.
  • They help develop tourism.
  • They can be used for hydro power generation.
  • They used for water supply and irrigation.

Q3. Below are given names of a few lakes of India. Group them under two categories natural and created by human beings.

  1. Wular
  2. Dal
  3. Nainital
  4. Bhimtal
  5. Gobind Sagar
  6. Loktak
  7. Barapani
  8. Chilka
  9. Sambhar
  10. Rana Pratap Sagar
  11. Nizam Sagar
  12. Pulicat
  13. Nagarjuna Sagar
  14. Hirakud

Ans. Natural lakes- Wular, Dal, Nainatal, Bhimtal, Loktak, Barapani, Chilka, Sambhar and Pulicat.

Lakes created by human beings- Gobind Sagar, Rana Pratap Sagar, Nizam Sagar, Nagarjuna Sagar and Hirakud.

Q4. Discuss the significant differences between the Himalayan and the Peninsular rivers.

Ans.

THE HIMALAYAN RIVERSTHE PENINSULAR RIVERS
They are mostly perennial.They are mostly seasonal in nature.
They perform intensive erosional activity in the upper courses.2. They hardly perform erosional activity in upper courses.
3. these rivers have long courses.3. these rivers have shorter courses.
4. these rivers bring new alluvium and enrich the plains.4. these rivers do not spread silt.
5. Ganga, Indus and Brahmaputra are the major rivers.5. Mahanadi, Narmada, Godavar, Krishna, Kaveri and Tapi are the major rivers.

Q5. Compare the east flowing and the west flowing rivers of the peninsular plateau.

Ans.

The east flowing riversThe west flowing rivers
1. The Mahanadi, Godavari, Krishna, Kaveri are the major east flowing rivers.1. The narmada and Tapi are the west flowing rivers.
2. these rivers drain into the Bay of Bengal.2. these rivers drain into the Arabian sea.
3. These rivers form deltas on the east coast.3. These rivers do not form any delta.
4. these rivers have a developed and large tributary system.4. these rivers are devoid of any developed tributary system.

Q6. Why are rivers important for the country’s economy?

Ans.

  • Rivers provide water which is essential for various human activities.
  • The river banks have attracted settlers from ancient times.
  • River water is used for irrigation and water supply.
  • River water is used for generate hydro- electricity.
  • Rivers moderate the climate of the surroundings and maintain the aquatic ecosystem.