Q59. How is Sunderban delta formed?
Ans. Enlarged with the waters from its right and left
bank tributaries, the Ganga flows eastwards till Farakka in West Bengal. This
is the northernmost point of the Ganga delta. The river bifurcates here; the
Bhagirathi-Hooghly (a distributary) flows southwards through the deltaic plains
to the Bay of Bengal. The mainstream, flows southwards into Bangladesh and is
joined by the Brahmaputra. Further down stream, it is known as the Meghna. This
mighty river, with waters from the Ganga, and the Brahmaputra, flows into the
Bay of Bengal. The delta formed by these rivers is known as the Sunderban
Q60. How lakes are formed?
Ans. Lakes are formed in the following ways:
Most of the fresh water lakes are formed
when glaciers dug out a basin, which was later filled with snowmelt.
The Wular lake in Jammu and Kashmir, in
contrast, is the result of the tectonic activity. The Dal lake, Bhimtal,
Nainital, Loktak and Barapani are some other important fresh water lakes.
Apart from natural lakes, the damming of
the rivers for the generation of hydel power has also led to the formation of
Lakes such as Guru Gobind Sagar (Bhakra Nangal Project).
Q61. What types of lakes are found in India? Give suitable
Ans. Types of lakes found in India
Fresh water lakes - Most of the fresh water
lakes are in the Himalayan region. They are of glacial origin. The
Dal lake, Bhimtal, Nainital, Loktak and Barapani are some other important fresh
Salt water lake - Example, the Sambhar lake
in Rajasthan, which is a salt water lake. Its water is used for producing salt.
Man-made lakes - Apart from natural lakes,
the damming of the rivers for the generation of hydel power has also led to the
formation of Lakes such as Guru Gobind Sagar (Bhakra Nangal Project).
Q62. Name the three Himalayan river systems. Write two
tributaries of each.
Ans. The three Himalayan river systems are:
Indus River System
Ganga River System
Brahmaputra River System
Indus River System – Satluj and Beas
Ganga River System – Yamuna and Ghaghara
Brahmaputra River System – Lohit and Dibang
Q63. Write some features of lakes.
Mention some characteristics of lakes.
Ans. Characteristics of lakes
India has many lakes. These differ from
each other in the size, and other characteristics.
Most lakes are permanent; some contain
water only during the rainy season, like the lakes in the basins of inland
drainage of semi-arid regions.
There are some of the lakes which are the
result of the action of glaciers and ice sheets, while the others have been
formed by wind, river action, and human activities.
Q64. Write a short note on the Brahmaputra River System.
The Brahmaputra rises in Tibet east of Mansarowar lake. It flows eastwards
parallel to the Himalayas. On reaching the Namcha Barwa (7757 m), it takes a
‘U’ turn and enters India in Arunachal Pradesh through a gorge. Here, it is
called the Dihang and it is joined by the Dibang, the Lohit, and many other
to form the Brahmaputra in Assam. In Tibet the river carries
a smaller volume of water and less silt as it is a cold and a dry area. In
India it passes through a region of high rainfall. Here the river carries a
large volume of water and considerable amount of silt. The Brahmaputra has a
braided channel in its entire length in Assam and forms many riverine islands.