Class 9 Geography Chapter 3 Notes – Drainage
here we provide class 9 geography chapter 3 notes. In drainage class 9 notes you will study different drainage system or river basin in India. drainage class 9 notes also help you in the competitive exams such as UPSC, SSC railway and teaching exams. You can also download class 9 geography chapter 3 notes pdf given in the end. You can also check NCERT Notes for all classes.
Drainage Class 9 Notes
- The term drainage describes the river system of an area.
- The area drained by a single river system is called a drainage basin.
- Any elevated area, such as a mountain or an upland, separates two drainage basins. Such an upland is known as a water divide
Drainage System in India
The drainage systems of India are mainly controlled by the broad relief features of the subcontinent. Accordingly, the Indian rivers are divided into two major groups:
- the Himalayan rivers; and
- the Peninsular rivers.
The Himalayan Rivers | The Peninsular Rivers |
---|---|
These rivers originate from glaciers. | These rivers originate on the plateau. |
Their catchment area is very large. | Their catchment area is very small. |
These rivers pass through gorges and carve deep valleys. | These rivers form shallow valleys. |
These rivers are young. | These have acquired maturity. |
These are engaged in high erosion activity and carry huge loads of silt and sand. | These have very little erosional activity. |
In the middle and the lower courses, these rivers form meanders, oxbow lakes, and many other depositional features in their floodplains. | not found |
They also have well- developed deltas. | – Which flow east make deltas – which flow west make esturies. |
These are useful for irrigation. | These are of little use for irrigation. |
These rivers are perennial, i.e., they flow throughout the year. | These rivers are non-perennial. |
Indus, Ganga, Brahmaputra Are The Main Rivers. | Godavari, Krishna, Kaveri, Narmada and Tapti are major rivers. |
The Himalayan Rivers
The major Himalayan rivers are the Indus, the Ganga and the Brahmaputra. These rivers are long, and are joined by many large and important tributaries. A river alongwith its tributaries may be called a river system.
The Indus River System
The river Indus rises in Tibet, near Lake Mansarowar. Flowing west, it enters India in the Ladakh district of Jammu and Kashmir. With a total length of 2900 km, the Indus is one of the longest rivers of the world. A little over a third of the Indus basin is located in India in the states of Jammu and Kashmir, Himachal Pradesh and Punjab and the rest is in Pakistan.
- It forms a picturesque gorge in this part.
- Several tributaries, the Zaskar, the Nubra, the Shyok and the Hunza, join it in the Kashmir region.
- The Indus flows through Baltistan and Gilgit and emerges from the mountains at Attock.
- The Satluj, the Beas, the Ravi, the Chenab and the Jhelum join together to enter the Indus near Mithankot in Pakistan.
- Beyond this, the Indus flows southwards eventually reaching the Arabian Sea, east of Karachi.
- The Indus plain has a very gentle slope.
The Ganga River System
The headwaters of the Ganga, called the ‘Bhagirathi’ is fed by the Gangotri Glacier and joined by the Alaknanda at Devaprayag in Uttarakhand. At Haridwar, the Ganga emerges from the mountains on to the plains.
Tributaries of Ganga:
- Yamuna– The river Yamuna rises from the Yamunotri Glacier in the Himalayas. It flows parallel to the Ganga and as a right bank tributary meets the Ganga at Allahabad.
- Ghaghara, Gandak and Kosi – These rivers rise in the Nepal Himalaya. They are the rivers, which flood parts of the northern plains every year, causing widespread damage to life and property, whereas, they enrich the soil for agricultural use.
- Chambal, the Betwa and the Son – These are main tributaries, which come from the peninsular uplands. These rise from semi-arid areas, have shorter courses and do not carry much water in them.
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 downstream, 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 Sundarban Delta.
The Brahmaputra River System
The Brahmaputra rises in Tibet east of Mansarowar lake very close to the sources of the Indus and the Satluj. It is slightly longer than the Indus, and most of its course lies outside India.Brahmaputra is known as the Tsang Po in Tibet and Jamuna in Bangladesh. 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 tributaries 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.
- It has a braided channel in its entire length in Assam and forms many riverine islands.
- Majuli world’s largest riverine island formed by the Brahmaputra
- Unlike other north Indian rivers, the Brahmaputra is marked by huge deposits of silt on its bed causing the riverbed to rise.
- This river also shifts its channel frequently.
The Peninsular Rivers
The main water divide in Peninsular India is formed by the Western Ghats, which runs from north to south close to the western coast.
- East Flowing: Mahanadi, the Godavari, the Krishna and the Kaveri flow eastwards and drain into the Bay of Bengal.
- These rivers make deltas at their mouths.
- West Flowing: Narmada and the Tapi are the only long rivers and many small streams flowing west.
- These rivers make Esturies
The Narmada Basin
The Narmada rises in the Amarkantak hills in Madhya Pradesh. It flows towards the west in a rift valley formed due to faulting. The ‘Marble rocks’, near Jabalpur, where the Narmada flows through a deep gorge, and the ‘Dhuadhar falls, where the river plunges over steep rocks, are some of the notable ones.
- All tributaries of the Narmada are very short and most of these join the main stream at right angles.
- The Narmada basin covers parts of Madhya Pradesh and Gujarat.
The Tapi Basin
The Tapi rises in the Satpura ranges, in the Betul district of Madhya Pradesh. It also flows in a rift valley parallel to the Narmada but it is much shorter in length. Its basin covers parts of Madhya Pradesh, Gujarat and Maharashtra.
The coastal plains between Western Ghats and the Arabian Sea are very narrow. Hence, the coastal rivers are short. The main west flowing rivers are Sabarmati, Mahi, Bharathpuzha and Periyar. Find out the states in which these rivers drain the water.
The Godavari Basin
The Godavari is the largest Peninsular river. It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra. Its length is about 1500 km. It drains into the Bay of Bengal. Its drainage basin is also the largest among the peninsular rivers. The basin covers parts of Maharashtra (about 50 per cent of the basin area lies in Maharashtra), Madhya Pradesh, Odisha and Andhra Pradesh. The Godavari is joined by a number of tributaries, such as the Purna, the Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga. The last three tributaries are very large. Because of its length and the area it covers, it is also known as the Dakshin Ganga.
The Mahanadi Basin
The Mahanadi rises in the highlands of Chhattisgarh. It flows through Odisha to reach the Bay of Bengal. The length of the river is about 860 km. Its drainage basin is shared by Maharashtra, Chhattisgarh, Jharkhand, and Odisha.
The Krishna Basin
Rising from a spring near Mahabaleshwar, the Krishna flows for about 1400 km and reaches the Bay of Bengal. The Tungabhadra, the Koyana, the Ghatprabha, the Musi and the Bhima are some of its tributaries. Its drainage basin is shared by Maharasthra, Karnataka and Andhra Pradesh.
The Kaveri Basin
The Kaveri rises in the Brahmagri range of the Western Ghats and it reaches the Bay of Bengal in south of Cuddalore in Tamil Nadu. The total length of the river is about 760 km. Its main tributaries are Amravati, Bhavani, Hemavati and Kabini. Its basin drains parts of Karnataka, Kerala and Tamil Nadu.
- The river Kaveri makes the second biggest waterfall in India, known as Shivasamudram Falls. The hydroelectric power generated from the falls is supplied to Mysuru, Bengaluru and the Kolar Gold Field.
Besides these major rivers, there are some smaller rivers flowing towards the east. The Damoder, the Brahmani, the Baitarni and the Subarnrekha etc.
Role of Rivers in the Economy
- Water from rivers is a basic natural resource,
- Using rivers for irrigation,
- navigation,
- hydro-power generation
Rivers are of special significance particularly to a country like India, where agriculture is the major source of livelihood of the majority of its population.
River Pollution
The growing domestic, municipal, industrial and agricultural demand for water from rivers naturally affects the quality of water. As a result, more and more water is being drained out of the rivers reducing their volume. On the other hand, a heavy load of untreated sewage and industrial effluents are emptied into the rivers. This affects not only the quality of water but also the self-cleansing capacity of the river.
increasing urbanisation and industrialisation, rising pollution are the main reason behind this.
Lakes
In India lakes are differ from each other in size and other characteristics. Most lakes are permanent; some contain water only during the rainy season. There are some lakes which are the result of the action of glaciers and ice sheets, while others have been formed by wind, river action and human activities.
A meandering river across a floodplain forms cut-offs that later develops into ox-bow lakes. Spits and bars form lagoons in the coastal areas, e.g. the Chilika lake, the Pulicat lake and the Kolleru lake. Lakes in the region of inland drainage are sometimes seasonal; for example, the Sambhar lake in Rajasthan, which is a salt water lake. Its water is used for producing salt.
Most of the freshwater lakes are in the Himalayan region. They are of glacial origin. They 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 tectonic activity. It is the largest freshwater lake in India. The Dal lake, Bhimtal, Nainital, Loktak and Barapani are some other important freshwater 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).
Lakes of large extent are called seas, like the Caspian, the Dead and the Aral seas.
Importance of a Lake
- A lake helps to regulate the flow of a river.
- During heavy rains, it prevents flooding and during the dry season, it helps to maintain an even flow of water.
- Lakes can also be used for developing hydel power.
- They moderate the climate of the surroundings;
- maintain the aquatic ecosystem,
- enhance natural beauty,
- help develop tourism and provide recreation.
Class 9 Geography Chapter 3 Notes – Do You Know?
- The world’s largest drainage basin is of the Amazon river
- 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.
- 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.
- 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.
Class 9th Geography Chapter 3 Notes – Find Out?
- Which river has the largest basin in India?
- The name of the biggest waterfall in India.
Class 9th Geography Chapter 3 Notes Pdf
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Class 9 Geography Chapter 3 Notes pdf
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