GEO (IX)- LESSON-3 DRAINAGE (LESSON NOTES)

  GEO (IX)- LESSON -3

     DRAINAGE

   (LESSON NOTES)

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v INTRODUCTION

  Ø Drainage describes as the rivers system of a particular area. As you know that small streams join together and form a river, that ultimately merge into sea or ocean. These small rivers are called tributary and the area drain by main river and its tributary is known as drainage basin. An elevated area, such as a mountain or an upland which separates two drainage basins is known as water divide.

 

Ø In this lesson we will learn about the work of river and the river system of India. We also learn about the lakes and importance of rivers.
v DRAINAGE SYSTEMS IN INDIA
Ø According to the relief features of India, the Drainage system of India are divided into two major groups:
Ø The Himalayan River system: -
§  Indus river system- Satluj, the Beas, the Ravi, the Chenab, the Jhelum
§  Ganga river system: - Ganga, Yamuna, chembal, betwa , ken , son
§  Brahmaputra river system: - Brahmaputra, Dibang, the Lohit
Ø The Peninsular rivers system: -
§  East flowing rivers: - Mahanadi, Godavari, Krishna, Kaveri
§  West flowing rivers: - Narmada, Tapi
v DIFFERENCE BETWEEN HIMALAYAN AND PENINSULAR RIVER SYSTEM

HIMALAYAN RIVER SYSTEM	PENINSULAR RIVER SYSTEM
1. Himalayan rivers are perennial. It means that they have water throughout the year.	Most of the peninsular rivers are seasonal so their flow is dependent on rainfall.
2. The Himalayan rivers have long courses.	These rivers have short course.
3. These rivers perform intensive erosional activity in their upper courses and carry huge loads of silt and sand.	These rivers have less erosional activity compare to Himalayan river.
4. They form large delta.	These formed small delta and estuaries.
5. There are three main rivers in Himalayan River system as Indus, Ganga and Brahmaputra,	There are two types of rivers in this system East flowing rivers-Mahandi, Godavari, Krishana, Kaveri West flowing rivers-Narmada, Tapi

 

v THE HIMALAYAN RIVERS

v INDUS RIVER SYSTEM: -
Ø Indus river originated from Mansarowar lake in Tibet and enter India from Ladakh.
Ø In this part small tributaries like the Zaskar, the Nubra, the Shyok and the Hunza join and also formed large gorge.
Ø The main tributaries like the Satluj, the Beas, the Ravi, the Chenab and the Jhelum join together to enter the Indus near Mithankot in Pakistan.
Ø Indus river flows nearly 2900 KM till it drops the water in the Arabian Sea, East of Karachi. Nearly 1/3 of its basin is located in India.
Ø According to the regulations of the Indus Water Treaty (1960), India can
use only 20 per cent of the total water carried by the Indus river system. This water is used for irrigation in Punjab, Haryana and the southern and the western parts of Rajasthan.

v THE GANGA RIVER SYSTEM
Ø The Ganga River is formed by joining of Bhagirathi River, which emerged from Gangotri Glacier, and Alaknanda at Devaprayag in Uttarakhand.
Ø At Haridwar, the Ganga emerges from the mountains in to the plains.
Ø Main tributaries of Ganga rivers are the Yamuna, the Ghaghara, the Gandak and the Kosi and the Son.
Ø The river Yamuna rises from the Yamunotri Glacier in the Himalayas and meets the Ganga at Allahabad. The tributaries which join Yamuna from
peninsular uplands, are the Chambal, the Betwa and the Ken.
Ø In West Bengal Ganga river divided into many distributaries such as Bhagirathi, Hooghly while main stream enter in Bangladesh, where Brahmaputra rivere joined and formed world largest delta, known as Sundarban Delta.
Ø The length of the Ganga river is over 2500 km. It formed the dendritic pattern. It has the largest basin in India.

v THE BRAHMAPUTRA RIVER SYSTEM
Ø The Brahmaputra rises in Tibet east of Mansarowar lake very close to the sources of the Indus and the Satluj. Here it is known as Tsang Po.
Ø It is slightly longer than the Indus, and most of its course lies outside India..
Ø After eastward flow it takes a ‘U’ turn from mountain Namcha Barwa (7757 m) and enters India in Arunachal Pradesh through a gorge. Here it is called as Dihang.
Ø Here, the Dibang, the Lohit, and many other tributaries join this river and known by Brahmaputra in Assam.
Ø The Brahmaputra has a braided channel in its entire length in Assam and forms many riverine islands. Majhuli is the world largest riverine island.
Ø Every year during the rainy season, the river overflows its banks, causing widespread devastation due to floods in Assam and Bangladesh.
v THE PENINSULAR RIVERS
Ø Peninsular rivers can be classified as east flowing and west flowing rivers as

WEST FLOWING RIVERS	EAST FLOWING RIVERS
1. The rivers which emerged from Vindhayas and satpura mountain and merge into Arabean sea after flowing westward are known as west flowing rivers.	The rivers which emerged from western ghat and merge into bay of Bengal after flowing eastward are known as east flowing rivers.
2. These rivers are small compare to east flowing rivers.	These rivers have long course
3. These rivers did not form the delta but they formed estuaries.	These rivers formed delta at their mouth.
4. Narmda and Tapi are the major river in west flowing river. Mahi, Sabarmati, , Bharathpuzha and Periyar are small rivers.	Mahanadi, Godavari, Krishana, Kaveri are the major rivers. Damoder, Brahmani, the Baitarni and the Subarnrekha are small rivers

 

v THE NARMADA BASIN
Ø The Narmada rises in the Amarkantak hills in Madhya Pradesh.
Ø It flows towards the west in a rift valley formed due to faulting.
Ø Narmada river creates many picturesque locations in its way as a deep gorge and Dhuadhar water fall near Jabalpur and
Ø All tributaries of the Narmada are very short and most of these join the main stream at right angles.
Ø The Narmada basin covers parts of Madhya Pradesh and Gujarat. Its length is 700 km.
v THE TAPI  BASIN
Ø The Tapi rises in the Satpura ranges, in Betul district of Madhya Pradesh.
Ø  It also flows in a rift valley parallel to the Narmada but it is
much shorter in length.
Ø Its basin covers parts of Madhya Pradesh, Gujarat and Maharashtra.
v THE GODAVARI BASIN
Ø The Godavari is the largest Peninsular River. It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra.
Ø Its length is about 1500 km. It drains into the Bay of Bengal.
Ø Its basin covers parts of Maharashtra (about 50 %) Madhya Pradesh, Odisha and Andhra Pradesh.
Ø The Godavari is joined by a number of tributaries, such as the Purna, the Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga.
Ø Because of its length and the area it covers, it is also known as the
Dakshin Ganga.
v THE MAHANADI BASIN
Ø The Mahanadi rises in the highlands of Chhattisgarh.
Ø  It flows through Odisha to reach the Bay of Bengal. The length of the river is about 860 km.
Ø Its drainage basin is shared by Maharashtra, Chhattisgarh, Jharkhand,
and Odisha.
v THE KRISHNA BASIN
Ø It risee from a spring near Mahabaleshwar, Maharashtra.
Ø The Krishna River flows for about 1400 km and reaches the Bay of Bengal.
Ø The Tungabhadra, the Koyana, the Ghatprabha, the Musi and the Bhima are some of its tributaries.
Ø Its drainage basin is shared by Maharasthra, Karnataka and Andhra Pradesh.
v THE KAVERI BASIN
Ø The Kaveri rises in the Brahmagri range of the Western Ghats.
Ø Its length is about 760 km and merge into Bay of Bengal in south of Cuddalore in Tamil Nadu.
Ø Its main tributaries are Amravati, Bhavani, Hemavati and Kabini.
Ø Its basin drains parts of Karnataka, Kerala and Tamil Nadu.
 
v LAKES
Ø Large reservoir of water is refereed as Lakes. It may be natural or manmade. There are many lakes in our country.
Ø IMPORTANC EOF LAKES :-Lakes are very important for human beings as:-
§  Lakes are very important to conserve the water. It help to recharge the ground water.
§  Lakes attract thousands of tourists every year. It boost up our economy.
§  Lakes are very helpful for irrigation activity.
§  Lakes are also used for boating, swimming and other water games.
§  A lake helps to regulate the flow of a river. During heavy rain it prevent flood while in summer it provides water.
§  Lakes can also be used for developing hydel power.
§  Lakes also help to moderate the climate of the surroundings; maintain the
aquatic ecosystem, enhance natural beauty.
Ø TYPES OF LAKES
§  Permanent or Temporary lakes:-
·      The lakes which have water in all seasons are known as permanent lakes. Some lakes have water only in rainy season are called temporary lakes.
§  Natural or Man made lakes
·      The lakes which are formed by erosional activity of glacier, wind or water are called as natural lakes. For example Dal and Wular lake (Srinagar), Bhimtal and Nainital(uttarkhand), Loktak (Manipur)and Barapani (Meghalaya)etc as while the lakes which is formed by human beings are called as man made lakes. For example Gobind Sagar(Punjab) Rana Pratap Sagar(Rajasthan) Nagarjuna Sagar (Andhra Pradesh) Hirakund(Odisha) etc.
§  Fresh water lakes or Salt lake
·      The lake which have fresh water are called as fresh water lakes.For example The Dal and Wular lake (Srinagar), Bhimtal and Nainital(uttarkhand), Loktak (Manipur)and Barapani (Meghalaya)etc. The lakes which have salty water are called as salty lakes. For example Sambhar lake (Jaipur), Lonar lake (Mahrashtra) etc.
§  Ox bow lakes:-
·      When a river flow by taking deep loops in plain areas due to slow speed (like a Snake) that is known as Meandering river. After some time these loop cut off from main river. These cut off loops are called as ox bow lakes.
§  Lagoon lakes

·      When a lake is formed due to saperation from large water body by barrier reef, coral reef or any natural barrier is known as lagoon lakes. For example Chilika lake (Odisha) , the Pulicat Tamilnadu) lake and the Kolleru lake (AndhraPredesh)

v ROLE OF RIVERS IN THE ECONOMY

Ø Rivers have great importance throughout the human history.
Ø Water from rivers is a basic natural resource, essential for various human activities. So many early settlements established on river banks as Harappan civilization or Mesopotamia civilization.
Ø Now a days many cities established on bank of rivers as Kanpur, Delhi, Agra, Lucknow, Kolkata etc.
Ø Rivers are used for irrigation, navigation, hydro-power generation etc., which develop the economy of the country.
Ø River played a very important role to develop agriculture in India. They not only provide the fertile plain but also provide water for irrigation.
 
v RIVER POLLUTION
Ø When the quality of the river water declined due to dump of the domestic, municipal, industrial and agricultural wastage is referred as river pollution. It makes the dirty for domestic and other purpose.
Ø Causes of river pollution
§  Industrial wastes
§  Sewage and Wastewater
§  Oil Leaks and Spills
§  Agriculture.
§  Global Warming.
Ø Action plans to clean the rivers
§  The river cleaning programme in the country was initiated with the launching of the Ganga Action Plan (GAP) in 1985. The Ganga Action Plan was expanded to cover other rivers under the National River Conservation Plan (NRCP) in the year 1995.
§  The objective of the NRCP is to improve the water quality of the rivers, which are major water sources in the country, through the implementation of pollultion abatement work.
§  The Namami Gange Programme is an Integrated Conservation Mission approved as a ‘flagship programme’ by the Union Government in June 2014 to accomplish the twin objectives of effective abatement of pollution, conservation and rejuvenation of the national river, Ganga.
§  The Narmada river conservation mission has been undertaken by the
government of Madhya Pradesh by a scheme named Namami Devi Narmade.
 
Ø The world’s largest drainage basin is of the Amazon river.
Ø India’s largest drainage basin is of the Ganga river.
Ø According to the regulations of the Indus Water Treaty (1960), India can
use only 20 per cent of the total water carried by the Indus river system.
Ø The Sundarban Delta derived its name from the Sundari tree, which grows well in marshland.
Ø Sunderban is the world’s largest and fastest growing delta. It is also the home of Royal Bengal tiger.
Ø Brahmaputra is known as the Tsang Po in Tibet and Jamuna in Bangladesh.
Ø Jog fall in Karnataka is the India highest waterfall. The river Kaveri makes the second biggest waterfall in India, known as Shivasamudram Falls.
Ø 71 per cent of the world’s surface is covered with water, but 97 per cent of
that is salt water. Of the 3 per cent that is available as freshwater, three quarters of it is trapped as ice.

Ø Lakes of large extent are called seas, like the Caspian, the Dead and the Aral seas.