CLASS 9
GEOGRAPHY
GIST OF THE LESSON TAUGHT :
CHAPTER 3 DRAINAGE
BASIC CONCEPTS -
➢ Drainage is a term which describes the river systems in an area.
➢ A drainage basin or river basin is an area which is drained by a single river system.
➢ An upland that separates two drainage systems that are next to each other is called a water
divide.
➢ On the basis of origin, there are two river systems of India- The Himalayan river system and The
Peninsular river system.
➢ A river along with its tributaries may be called a river system.
FEATURES OF THE HIMALAYAN RIVERS
➢ Himalayan rivers are rainfed and snowfed, so they have water in them throughout the
year, i.e., they are perennial.
➢ They perform intense erosional activity in the upper course.
➢ In the lower course, they carry huge loads of silt and sand.
➢ They create meanders, ox bow lakes and other depositional features on their course.
FEATURES OF THE PENINSULAR RIVERS
➢ Peninsular rivers are seasonal, mostly depending on rainfall.
➢ Most of the rivers of Peninsular India originate in the Western Ghats and flow towards
the Bay of Bengal.
DRAINAGE PATTERNS
The streams within a drainage basin form certain patterns, depending on the slope of land,
underlying rock structure as well as the climatic conditions of the area.
TYPES OF DRAINAGE PATTERNS :
➢ Dendritic drainage pattern
➢ Trellis drainage pattern
➢ Rectangular drainage pattern
➢ Radial drainage pattern
THE HIMALAYAN RIVERS
The major rivers are the Indus, the Brahmaputra, the Ganga.
THE INDUS RIVER SYSTEM
➢ Rising from Lake Mansarowar in Tibet, the Indus enters India in the Ladakh district of
Jammu and Kashmir.
➢ Zaskar, Nubra , Shyok, Hunza are the tributaries in Kashmir.
➢ Rivers Satluj, Beas, Ravi, Chenab and Jhelum join Indus in Mithankot, Pakistan and flow
southwards to fall into the Arabian sea, east of Karachi.
➢ With a total length of 2900 km, the Indus is one of the longest rivers of the world.
India and Pakistan have distributed Indus river water according to Indus Water Treaty in 1960.
THE GANGA RIVER SYSTEM
➢ The headwaters of the Ganga called Bhagirathi, is fed by the Gangotri glacier and joined
by the Alakananda at Devaprayag in Uttarakhand.
➢ Ganga receives the tributaries from the Himalayas such as Ghaghara, Gandak and Kosi.
➢ A major river Yamuna, arising from Yamunotri glacier in the Himalayas, joins Ganga at
Allahabad.
➢ Other tributaries- Chambal, Betwa and Son- come from Peninsular uplands to join
Ganga.
➢ Farakka in West Bengal is the northernmost point of the Ganga Delta.
➢ The river bifurcates into Bhagirathi-Hooghly (a distributary) and flows southwards to
reach Bay of Bengal.
➢ The mainstream flows southwards into Bangladesh and is joined by Brahmaputra and
forms river Meghna which flows to reach the Bay of Bengal.
➢ The delta formed when the Ganga and the Brahmaputra flow into the Bay of Bengal is
known as the Sunderban Delta.
➢ The length of the Ganga is over 2500 km and it develops large meanders in the
downstream plain areas.
THE BRAHMAPUTRA RIVER SYSTEM
➢ Originating in Tibet, very close to the sources of Indus and Sutlej, most of its course lies
outside India.
➢ On reaching Namacha Barwa it takes a ‘U’ turn and enters Arunachal Pradesh to flow to
Assam joined by many tributaries.
➢ The tributaries are Dibang, Lohit etc.
➢ The Brahmaputra has a braided channel in its entire length in Assam to form many
riverine islands. World’s largest riverine island ‘Majuli’ IS FOUND IN Brahmaputra.
➢ Unlike other north Indian rivers, the Brahmaputra is marked by huge deposits of silt on
its bed, causing the riverbed to rise.
➢ The river is known by different names in different sections of its course
➢ Tsang Po ➢ Tibet
➢ Dihang ➢ Arunachal Pradesh
➢ Brahmaputra ➢ Assam
➢ Jamuna ➢ Bangladesh
THE PENINSULAR RIVERS
➢ Western Ghats form the main water divide for peninsular India.
➢ The major rivers – Mahanadi, Godavari, Krishna, Kaveri- flow eastwards to drain into the
Bay of Bengal.
➢ The Tapi and Narmada are the only rivers which flow west to make estuaries and drain
into the Arabian sea.
➢ The drainage basins of peninsular rivers are comparatively small in size.
THE NARMADA BASIN
➢ Rising in the Amarkantak hills, it flows to create a gorge in marble rocks of
Madhya Pradesh.
➢ It flows towards the west in a rift valley formed through faulting.
➢ Near Jabalpur it flows in the form of deep gorge in the marble rocks and
Dhuadhar falls are picturesque locations.
THE TAPI BASIN
➢ Originating in Betul, Madhya Pradesh in Satpura ranges.
➢ It also flows in a rift valley parallel to the Narmada but is much shorter than
Narmada.
➢ Tapi flows through a basin that covers Madhya Pradesh, Gujarat and
Maharashtra.
OTHER WEST FLOWING RIVERS include- Sabarmati, Mahi, Bharatpuzha
and Periyar.
THE GODAVARI BASIN
➢ Godavari begins in Nasik district of Maharashtra and is the largest peninsular
river about 1500 km.
➢ Its large basin covers most parts of Maharashtra, Madhya Pradesh, Orissa and
Andhra Pradesh.
➢ The tributaries which join the river include- Purna, Wardha, Pranhita, Manjra,
Waiganga and Penganga.
➢ Because of its length and area it covers, Godavari is also known as ‘Dakshin
Ganga’.
➢ It drains into the Bay of Bengal.
THE MAHANADI BASIN
➢ The Mahanadi, a 860km long river, rises in Chattisgarh to flow through Orissa to
reach the Bay of Bengal.
➢ Mahanadi river basin is shared by Maharashtra, Orissa, Jharkhand and
Chattisgarh.
THE KRISHNA BASIN
➢ The 1400km long Krishna river rises from a spring near Mahabaleshwar to reach
the Bay of Bengal.
➢ The tributaries include Bhima, Musi, Ghatprabha, Koyana and Tungabhadra. The
Krishna basin is shared by Maharashtra, Karnataka and Andhra Pradesh.
THE KAVERI BASIN
➢ It originates in the Brahmagiri range of the Western Ghats and reaches the Bay
of Bengal.
➢ It shares its basin with Karnataka, Tamil Nadu, Kerala.
➢ The river makes the second biggest waterfall in India known as Sivasamudram.
OTHER EAST FLOWING RIVERS include- Damodar, Brahmani, Baitarani
and Subarnalekha.
LAKES
➢ Most lakes are permanent while other contain water only during the
rainy season.
➢ Some lakes are result of the glacial action and ice sheets and some may
have been formed by wind, river action and human activities.
➢ A river meandering across a floodplain forms cut-offs that later develop
into oxbow lakes.
➢ Spits and bars form lagoons in the coastal areas, eg the Chilika lake,
Pulicat lake.
➢ Lakes in regions of inland drainage are sometimes seasonal; eg
Sambhar lake in Rajasthan (salt water lake).
➢ Glacial lakes are formed when glaciers dig out basin which is later filled
with snowmelt.
➢ Some lakes like Wular Lake in Jammu and Kashmir result from tectonic
activity.
➢ Apart from natural lakes, the damming of the rivers for the generation
of hydel power has also led to the formation of lakes.
➢ Lakes help in the following ways-
• To regulate river water flow
• Prevent flooding
• Aid to develop hydel power
• Moderate climate
• Maintain aquatic ecosystem
• Enhance natural beauty
• Develop tourism
• Provide recreation
ROLE OF RIVERS IN THE ECONOMY
➢ Rivers are natural sources of water.
➢ Settlements on the river banks have developed into cities.
➢ Rivers are used for irrigation, navigation, hydro-power generation, all vital for India,
an agricultural economy.
RIVER POLLUTION
➢ Quality of river water is affected by the growing domestic, municipal,
industrial and agricultural demand.
➢ A heavy load of untreated sewage and industrial effluents are emptied into
the river affecting the river’s self-cleaning property.
➢ Concern over rising pollution in our rivers led to launching of various action
plans to clean the rivers like National River Conservation Plan (NRCP).
MAP POINTING LIST OF DRAINAGE ( 2020-2021)
RIVERS (Identification only)
• The Himalayan river systems: The Indus, The Ganges and The Satluj
• The Peninsular river systems: The Narmada, The Tapi, The Kaveri, The Krishna, The
Godavari, The Mahanadi
LAKES : Wular, Pulicat, Sambhar, Chilika
ASSIGNMENT NO. 5 (TO BE MAILED) :
1.Choose the correct option- [1]
Which one of the following is not a freshwater lake of India?
i. Wular lake
ii. Loktak lake
iii. Sambhar lake
iv. Dal lake
2.Match the following- [1 X 3=3]
COLUMN A COLUMN B
i. Yamuna a. Known as ‘Dakshin Ganga’
ii. Narmada b. Largest tributary of Ganga
iii. Godavari c. Other name of Brahmaputra
----- d. Flows through rift valley
3.Fill in the blank- [1]
When the streams flow in different directions from a central peak or dome like
structure, a _______________________ drainage pattern is developed.
4.Name the following in one or two words [1]
An upland separating two drainage basins.
____________________ .
5.Write the full form of NRCP. [1]
_________________________________
6.What are the characteristics features of the Peninsular rivers?(any 3 points) [3]
EMAIL ID OF EVALUATORS
9 A (M) rukmabasu42@gmail.com
9 B (M) rukmabasu42@gmail.com
9 C (M) srabanabanerji@gmail.com
9 D (M) satabdi.sphs@gmail.com
9 E (M) mal.tanu@gmail.com
9 F (M) srabanabanerji@gmail.com
9 G (M) anushilbanerjee@gmail.com
9 H (M) biswaschandreyee@gmail.com
9 A (A) arunima.sphs@gmail.com
9 B (A) ankita.southpoinths@gmail.com
9 C (A) ushasi.dutta.sphs@gmail.com
9 D (A) arunima.sphs@gmail.com
9 E (A) chatterjee.sutapa2014@gmail.com
9 F (A) ushasi.dutta.sphs@gmail.com
9 G (A) dmsaraswati0@gmail.com
9 H (A) nandinisengupta23@gmail.com
PLEASE NOTE: We are asking you to submit through the app also in order to enable
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DATE OF ASSIGNMENT SET : 6th June 2020
DUE DATE: 13th June 2020
