In this article ,we have given Drainage Notes Class 9 Geography which would help students to have clear understanding of drainage, drainage basin,river system, Himalayan rivers, peninsular rivers, lakes and rivers pollution etc.Chapter 3 Drainage Notes class 9 Geography here is enough for students to have confidence to get good marks.
Class 9 Geography Drainage Notes
Drainage
Drainage describes the river system of an area.
River System
The small streams flowing from the different directions along with the main river is called the river system of main river.
Drainage Basin
The area drained by a single river system is called a drainage basin.
Water Divide
Any upland or a mountain separating two adjoining drainage basins is known as water divide.
Drainage Systems in India
Drainage system in India is defined by the broad relief features of Indian subcontinent.On that basis the drainage systems are divided into two main groups
the Himalayan rivers and the Peninsular rivers.
Himalayan rivers:
- These rivers are mostly perennial, means they flow throughout the year.
- They are fed by rainwater as well as melted snow from the high mountains.
- Himalayan rivers have long courses from their source in the mountains .
- These rivers form meanders, ox bow lake and many other depositional features
- Major rivers like the Indus,Ganga and the Brahmaputra are Himalayan rivers
Peninsular rivers:
- Peninsular rivers are seasonal, relying heavily on rainfall for their flow.
- Most of these rivers originate in the Western Ghats and flow eastwards towards the Bay of Bengal.
- Peninsular rivers have shorter and shallower courses.
- Godavari, Krishna and Kaveri are peninsular rivers
The Himalayan Rivers
- The Indus River System
- one of the longest rivers hav length of 2900 km.
- Rises in Tibet near Lake Mansarovar and enters India through the Ladakh region of Jammu and Kashmir form gorges.
- Zaskar,Nubra,Shyok and Hunza join it in Kashmir region.
- In Pakistan, the Indus is joined by major tributaries including the Satluj, Beas, Ravi, Chenab, and Jhelum near Mithankot.
- A little over one-third of Indus basin is in the states of Jammu and Kashmir, Himachal Pradesh and Punjab.
Indus Water Treaty
According to the regulations of Indus Water Treaty (1960),India can use only 20 percent of total water that is used by Punjab, Haryana and Southern and western parts of Rajasthan for irrigation.
- The Ganga River System
- originate as the Bhagirathi from the Gangotri Glacier and is joined by the Alaknanda at Devaprayag in Uttarakhand.
- It emerges from the Himalayas into the plains at Haridwar, where it begins its journey through northern India.
- Major rivers like the Yamuna, Ghaghara, Gandak, and Kosi are tributaries emerge from Himalayas.
- Yamuna rises from yamunotri glaciers and flow parallel to Ganga and join it as right bank tribtutary at Allahabad.
- Chambal, Betwa ,Ken and Son rise from semi arid and peninsular uplands are also tributaries.
- With a length over 2500 km, the Ganga flows southeastward and bifurcates at the northernmost point of the Ganga Delta in Farakka, West Bengal.
- The Bhagirathi-Hooghly (distributary) branch continues southward through deltaic plains to the Bay of Bengal
- the mainstream flows southward into Bangladesh and join with the Brahmaputra to form the Meghna River.
- The Sundarbans Delta is formed by these rivers, is world’s largest and fastest growing delta and home to Royal Bengal Tiger.
Namami Gange Programme
It is an integrated conservation mission approved as flagship programme by the Union Govt in June 2014 to accomplish twin objectives of effective abatement of pollution, conservation and rejuvenation of national river Ganga.
3) The Brahmaputra River System:
- Rises in Tibet east of Mansarovar Lake, clo to the source of the Indus and Satluj.
- Flows parallel to Himalayas and after reaching the Namcha Barwa (7757 m)it takes ‘U-turn’ and enter India as the Dihang in Arunachal Pradesh.
- In Assam, the Dihang is joined by major tributaries like the Dibang and Lohit to form the Brahmaputra.
- In Tibet, river carries smaller volume of water and less silt as it is cold and dry area.
- Brahmaputra has braided channel in its entire length in Assam and forms riverine islands.
- During rainy season, river overflows it’s banks causing widespread devastation due to floods in Assam Bangladesh
- Barahmaputra river is known as Tsang PO in Tibet and Jamuna in Bangladesh.
Physical Features of India Class 9 Notes
Peninsular Rivers
The Water divide in Peninsular India is formed by Western Ghats .Most of the rivers flow eastwards and drain into bay of Bengal and make deltas at their mouth while Narmada and Tapi are the only long west flowing rivers form estuaries. Drainage basin area of peninsular rivers are comparatively smaller in size
West Flowing Rivers
Narmada and Tapi are two important west flowing rivers.Apart from it, Sabarmati,Mahi,Bharathpuzha and periyar.
The Narmada Basin:
- originates in the Amarkantak hills in Madhya Pradesh.
- Flows in a rift valley formed due to faulting
- passes through the picturesque Marble Rocks near Jabalpur and plung down steep rocks at Dhuadhar Falls.
- Narmada basin covers parts of Madhya Pradesh and Gujarat.
- Narmada River Conservation Mission is undertaken by Madhya Pradesh by a scheme named Namami Devi Narmade.
The Tapi Basin
- rises in the Satpura ranges in Betul district of Madhya Pradesh.
- Its basin covers Madhya Pradesh, Gujarat, and Maharashtra.
East Flowing Rivers
The Godavari Basin
- the largest Peninsular river, having length of 1500 km.
- Rises from the slopes of the Western Ghats in Nasik district of Maharashtra.
- basin covers regions of Maharashtra(50 percent of total basin area), Madhya Pradesh, Odisha, and Andhra Pradesh.
- Largest basin area among the peninsular rivers.
- It is often referred to as Dakshin Ganga
- tributaries including the Purna, Wardha, Pranhita, Manjra, Wainganga, and Penganga.
The Mahanadi Basin
- Originate in the highlands of Chhattisgarh.
- flows for about 860 km through Maharashtra, Chhattisgarh, Jharkhand, and Odisha.
The Krishna Basin
- Rise from a spring near Mahabaleshwar range.
- have length of 1400 km make it second largest peninsular river
- Basin area is shared by Maharashtra, Karnataka, and Andhra Pradesh.
- Tungabhadra,Koyana,Ghatprabha,Musi and Bhima are the tributaries.
The Kaveri Basin
- Starts from the Brahmagiri range of the Western Ghats
- Length of about 760 km passes across Karnataka, Kerala, and Tamil Nadu
- Amravati, Bhavani,Hemavati and Kabini are the main tributaries
Some east Flowing rivers are damodar,Brahmini,Baitarni and Subarnarekha .
Fact: Jog fall, second biggest waterfall is formed by Kaveri river and hydroelectricity generated by it supplied to Mysuru, Bengaluru and Kolar Gold Field.
Lakes
Types of Lakes
Seasonal Lake
They contain water during dry season like the lake in the basin of inland drainage of semi arid regions .Sambhar Lake in Rajasthan,a saltwater lake and seasonal in nature.
Lakes in Plains
- Meandering river forms cut off that converts into ox-bow lake.
- Split and bars form lagoon in coastal areas
- Chilika lake,Pulicat lake and the Kolleru lake
Freshwater Lakes
- Formed in Himalayan region when glaciers dug out a basin.
- Wular lake , the largest freshwater lake is formed by the tectonic activity.
- Wular lake ,Dal lake, Bhimtal, Nainital,Loktak Lake and Barapani are freshwater Lakes
Importance of Lakes
- Help to regulate the flow of river
- Prevents flooding of river during monsoon
- Help to maintain the consistent flow of water during dry season
- Used for generating hydroelectricity
- Moderates the climate of the surroundings
- Maintain aquatic life and enhances natural beauty
- Promote tourism and provide recreation to tourists.
Role of Rivers in the Economy
- Basic natural resource essential for various human activities
- Attracted settlers from ancient times for settlement that developed into cities.
- Used for irrigation, navigation, hydroelectric power generation
- Agriculture provides livelihood to majority of the population that is possible as river a source of irrigation.
River Pollution
- Grow demands for domestic, municipal, industrial, and agricultural purposes affect the quality of river water
- heavy amount of untreated sewage, industrial effluents, and agricultural runoff laden with chemicals not only degrade water quality but also the cleansing capacity of the water .
- Increasing urbanisation also put pressure on proper disposal of garbage.
Chapter 3 Drainage Notes