Answer the following questions briefly.
(i) What is meant by a water divide? Give an example.
(ii) Which is the largest river basin in India?
(iii) Where do the rivers Indus and Ganga have their origin?
(iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?
(v) Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?
(vi) Which two Peninsular rivers flow through trough? (vii) State some economic benefits of rivers and lakes.
Answers
Answer:
i) Separation of two drainage basins by a mountain or an elevated area is called water divide. Example- western ghats.
ii) The largest river basin of India is the Ganga basin.
iii) River Indus rises near lake Mansarovar in Tibet and Ganga originates from Gangotri glacier of Himalayas.
iv) Bhagirathi and Alaknanda are two headstreams of Ganga and they meet at Devaprayag in Uttarakhand.
v) River Indus , in Tibet carries less silts and smaller volume of water because of the dry and cold weather. But in India, due to the high rainfall it carries more silt and more volume of water.
vi)Tapti and Narmada are two peninsular rivers flowing through a trough.
vii) a) Lakes help regulating river flow
b) helps preventing flood.
c) Rivers help in fisheries, irrigation
d) development of hydel power.
Explanation:
Answer:
(i) Water Divide:
Any high or elevated piece of land which separates two water basins is called a "water divide".
For Example: water divide present between Ganga and Indus water basins.
(ii) The "largest river basin" in India is the "Ganga basin".
(iii) The rivers Indus and Ganga have their origin in Tibet near Mansarovar lake and Gangotri glacier in Himalayas.
(iv) The two headstreams of the Ganga are "Bhagirathi" and "Alaknanda". They meet to form the Ganga at "Devprayag" in "Uttarakhand".
(v) The "Brahmaputra" in its "Tibetan part" have less silt, despite a longer course due to the minimal amount of water it receives in Tibet. In India it has a lot of water hence more silt.
(vi) "Two Peninsular rivers" flow through trough are "Narmada" and "Tapi".
(vii) Some "economic benefits" of rivers and lakes are they provide sources of recreation and promote tourism. They also generate revenue due to activities such as "fishing and boating".