Drainage class 9 geography MCQ & SAQ

Drainage class 9 geography NCERT SOLUTION:

 

What is meant by the water divide? Give an example.

Any elevated area, such as a mountain or upland, separates two drainage basins. Such upland is known as the water divide. Ambala is located on the water divide between the Indus and the Ganga river systems.

 

Which is the largest river basin in India?

The Ganga basin is the largest basin in India.

 

Where do the rivers Indus and Ganga have their origin?

The headwaters of the Ganga called the ‘Bhagirathi’ are fed by the Gangotri Glacier and joined by the Alaknanda at Devprayag in Uttaranchal. At Haridwar, the Ganga emerges from the mountains onto the plains. The Indus flows through Baltistan and Gilgit and emerges from the mountains at Attock.

 

Name the two headstreams of the Ganga. Where do they meet to form the Ganga?

Alakananda and Bhagirathi are the two headstreams of the Ganga. They meet at Devprayag.

Question-5

Why does the Brahmaputra in its Tibetan part have less silt, despite a longer course?

Solution:

The Brahmaputra river, which is known as Tsangpo in Tibet, receives a very little volume of water in Tibet so it has less silt there. On the other hand, when this river enters India it passes through such a region which receives heavy rainfall. As such in India, it carries a large volume of water and a larger amount of silt.

Question-6

Which two Peninsular rivers flow through?

Solution:

Narmada and Tapi are the two Peninsular rivers, which flow through the trough.

Question-7

Discuss the significant difference between the Himalayan and the Peninsular rivers.

Solution:

The Himalayan Rivers The Peninsular or Deccan Rivers

1. The Himalayan rivers rise in the snow-covered mountains as such they flow throughout the year. The mountains in which the Deccan rivers rise are not snow-covered. Hence they dry up in summer.

2. The Himalayan rivers flow in leveled Northern Plains. Therefore, they are quite useful for navigation and irrigation. The Peninsular rivers flow on the uneven rocky surface. Therefore they are neither navigable nor useful for irrigation.

3. The Himalayan rivers bring with them fertile alluvium which they deposit in the Indo-Gangetic Plains. The Peninsular rivers do not bring with them enough alluvium. As the current is swift so the deposition activity is negligible.

4. Canals have been dug to use the water of these rivers for irrigation. As the terrain is rocky and the banks of these rivers are high, canals cannot be dug. However, dams are built to store the floodwater for irrigation with the help of small channels.

5. Many important towns and centers of trade are situated on the banks of these rivers. Very few important towns and centers of trade are situated on the banks of these rivers.

6. The porous soil absorbs a lot of water, which is later on used as groundwater by digging wells and tube wells for domestic and irrigation purposes. The rocky soil does not absorb any water. Hence no wells can be dug. All the water flows down the sea at one and the same time.

Question-8

Compare the east-flowing and the west-flowing rivers of the Peninsular plateau.

Solution:

East Flowing Rivers

The Mahanadi, the Godavari, the Krishna, and the Kaveri are the main east flowing rivers of Peninsular India. These rivers drain in the Bay of Bengal. These rivers make deltas at their mouth

West Flowing Rivers.

These rivers have a developed tributary system. Their tributaries are comparatively large in size. These rivers flow through not very deep channels.

The Narmada and the Tapi are the main west-flowing rivers of Peninsular India. These rivers drain in the Arabian Sea. These rivers enter the sea through estuaries. These rivers are devoid of developed tributary systems. Their tributaries are quite small in size. These rivers flow in a trough or a funnel-like narrow but deep channel.

Question-9

Why are rivers important for the country’s economy?

Solution:

Rivers have been of fundamental importance throughout human history. Water from the rivers is a basic natural resource, essential for various human activities. Therefore, the riverbanks have attracted settlers from ancient times. These settlements have now become big cities. Make a list of cities in your state, which is located on the bank of a river. Using rivers for irrigation, navigation, hydropower generation is of special significance – particularly to a country like India, where agriculture is the major source of livelihood of the majority of its population.

Drainage class 9 geography MCQ 

 

 

1. Which of the following affects the self-cleansing capacity of the river?

(a) Aquatic organisms

(b) Drawing of water for irrigation

(c) Hydroelectricity generation

(d) Pollution

► (d) Pollution

 

2. Lakes are of great value to human beings. Which of the following statements about lakes

Is the given below incorrect?

(a) Helps to regulate the flow of rivers

(b) It results in flooding

(c) Can be used for developing hydel power

(d) Enhances natural beauty

► (b) It results in flooding

 

3. Which of the following is the result of concern over rising pollution in our rivers?

(a) Banning hydroelectric projects

(b) Various river action plans

(c) Rainwater harvesting

(d) None of the above

► (b) Various river action plans

 

4. Why have the river banks attracted settlers from ancient times?

(a) Water is a basic natural resource

(b) Rivers provide water for irrigation

(c) Rivers provide facilities for inland navigation

(d) All the above

► (d) All the above

 

5. Which of the following is an artificial lake located in Andhra Pradesh?

(a) Kolleru

(b) Nagarjuna Sagar

(c) Krishnaraja Sagar

(d) Vembanad

► (b) Nagarjuna Sagar

 

6. Which one of the following freshwater lakes is the largest?

(a) Wular

(b) Loktak

(c) Nainital

(d) Dal

► (a) Wular

 

7. Why have the river banks attracted settlers from ancient times?

(a) Water is a basic natural resource

(b) Rivers provide water for irrigation

(c) Rivers provide facilities for inland navigation

(d) All the above

► (d) All the above

 

8. Which of the following lakes is a lagoon in the coastal region of Orissa?

(a) Bhimtal

(b) Barapani

(c) Chilika

(d) Hirakud

► (c) Chilika

 

9. Which of the following types of lakes is formed due to river action?

(a) Saltwater lakes

(b) Glacial lakes

(c) Oxbow lakes

(d) Lagoons

► (c) Oxbow lakes

 

10. Which one of the following lakes is a saltwater lake?

(a) Wular Lake

(b) Sambhar Lake

(c) Barapani Lake

(d) Dal Lake

► (b) Sambhar Lake

 

11. Which of the following is a famous lake of Srinagar in Kashmir?

(a) Sambhar

(b) Bhimtal

(c) Chilika

(d) Dal

► (d) Dal

 

12. Which of the following waterfalls is made by the river Kaveri and is the second biggest waterfall in India?

(a) Jog

(b) Sivasamudram

(c) Dhuadhar

(d) Hundru

► (b) Sivasamudram

 

13. Which of the following rivers rises from the slopes of the Western Ghats in the Nasik

district of Maharashtra?

(a) Mahanadi

(b) Narmada

(c) Godavari

(d) Koyna

► (c) Godavari

14. The Amravati, Bhavani, Hemavati and Kabini are the tributaries of which of the

following rivers?

(a) Wainganga

(b) Bhima

(c) Krishna

(d) Kaveri

► (d) Kaveri

 

15. Which of the following rivers is known as the ‘Dakshin Ganga’?

(a) The Godavari

(b) The Narmada

(c) The Krishna

(d) The Kaveri

► (a) The Godavari

 

16. The Tungabhadra and the Koyna are tributaries of which of the following rivers?

(a) Godavari

(b) Krishna

(c) Kaveri

(d) Narmada

► (b) Krishna

 

17. Which of the following is the second longest river of Peninsular India?

(a) Godavari

(b) Krishna

(c) Kaveri

(d) Mahanadi

► (b) Krishna

 

18. Which of the following rivers rises from a spring near Mahabaleshwar?

(a) Krishna

(b) Narmada

(c) Tungabhadra

(d) Purna

► (a) Krishna

 

19. Which place is located on the water divide between the Indus and the Ganga river system ?

(a) Ambala

(b) Nainital

(c) Haridwar

(d) Allahabad

► (a) Ambala

 

20. In which of the following states is Sambhar Lake situated ?

(a) Rajasthan

(b) Uttar Pradesh

(c) Bihar

(d) Jammu and Kashmir

► (a) Rajasthan

 

21. Which kind of a drainage pattern is formed when tributaries join rivers at almost right angles ?

(a) Dendritic drainage

(b) Trellis drainage

(c) Rectangular drainage

(d) Radial drainage

► (b) Trellis drainage

 

22. The River Mahanadi rises from which one of the following states ?

(a) Madhya Pradesh

(b) Chhattisgarh

(c) Jharkhand

(d) West Bengal

► (b) Chhattisgarh

 

23. Which one of the following statements about the river Narmada is not true?

(a) It flows through a rift valley

(b) It flows through a gorge near Jabalpur

(c) It plunges over steep rocks at the Dhuandhar falls

(d) Its tributaries are Tungabhadra and Music

► (d) Its tributaries are Tungabhadra and Music

 

24. Which of the two states does river Kaveri pass through ?

(a) Kerala and Karnataka

(b) Karnataka and Tamil Nadu

(c) Kerala and Tamil Nadu

(d) Andhra Pradesh and Tamil Nadu

► (b) Karnataka and Tamil Nadu

 

25. Which one of the following is not a tributary of the River Ganga?

(a) Yamuna

(b) Beas

(c) Ghagra

(d) Kosi

► (b) Beas

 

26. Which one of the following is a southern tributary of the Ganga?

(a) Ghaggar

(b) Son

(c) Gomti

(d) Gandak

► (b) Son

 

27. Meanders are formed in which one of the following courses of a river?

(a) Upper course

(b) Middle course

(c) Lower course

(d) Both upper and middle

► (c) Lower course

 

28. Which one of the following drainage patterns does the Ganga river form?

(a) The Trellis Pattern

(b) The Radial Pattern

(c) The Dendritic Pattern

(d) The Rectangular Pattern

► (c) The Dendritic Pattern

 

29. Which of the following is not a tributary of Godavari?

(a) Purna

(b) Wardha

(c) Wainganga

(d) Lohit

► (d) Lohit

 

30. Which one of the following is a southern tributary of the Ganga?

(a) Ghaggar

(b) Son

(c) Gomti

(d) Gandak

► (b) Son

 

31. Which of the following describes drainage patterns resembling branches of a tree?

(a) Radial

(b) Centrifugal

(c) Dendritic

(d) Trellis

► (c) Dendritic

 

32. Which one of the following lakes differs from the rest in the group?

(a) The Dal lake

(b) The Nainital Lake

(c) The Guru Gobinda Sagar

(d) The Bhimtal Lake

► (c) The Guru Gobinda Sagar

Drainage class 9 geography SAQ

Q.1.What    are    perennial    and    non-perennial    rivers?    Give    reasons    why    the    Himalayan    region consists of perennial rivers.

Ans.1. The rivers that flow throughout the year are termed as perennial rivers. They have more or less even flow throughout the year, e.g., the Ganga.

1.    The rivers that do not flow throughout the year are termed as non-perennial rivers. They are seasonal rivers that flow mainly during the rainy season and dwindle during the dry period, e.g., the Subarnarekha.

2.    The rivers of the Himalayan region are perennial in nature. They have their sources in the snow fields and glaciers of the Himalayas which supply water to these rivers throughout the year.

4. During monsoons the  Himalayas receive very heavy rainfall and rivers discharge heavy flow of water. During

dry periods the rivers are fed by the melting snow and glaciers of the lofty great Himalayan range. Hence, the Himalayan rivers flow throughout the year.

 

Q.2. Why  is  the  Godavari  often  referred  to  as  the  'Dakshin  Ganga'?  Write  a  note  on   the   river Godavari and its tributaries.

Ans. The Godavari is the largest Peninsular River. It has a length of 1500 km. It has the largest drainage basin amongst the Peninsular Rivers. Its drainage basin covers parts of Maharashtra, Madhya Pradesh, Orissa and Andhra Pradesh. On account of its dominating length and the extent of area it covers, the Godavari is known as the ‘Dakshin Ganga’.

The Godavari rises from the slopes of the Western Ghats in the Nasik district of Maharashtra. It flows eastwards and drains into the Bay of Bengal. Nearly half of its drainage basin lies in The Godavari is joined by large tributaries–the Wainganga, the Penganga and the Manjra. The Purna, the Wardha and the Pranhita are its other tributaries.

 

Q.3. how are salt lakes formed? Give examples of salt lakes in India.

Ans. Lakes which have water with high salt content are called salt lakes. They are usually found in the basins of inland drainage in the regions of arid and semi-arid climate. Such lakes are seasonal in nature.

Hollows may be created in the deserts due to the deflation action of the winds. These may reach the groundwater level which seeps out into these depressions. Small shallow lakes are formed which become salt lakes due to excessive evaporation.

Sometimes short, intermittent streams drain into low depression or a desert basin and form temporary lakes. Such short lived lakes also contain a high percentage of salts on account of the high rate of evaporation.

An example of such saltwater lake is the Sambhar lake of Rajasthan. The water of this salt lake is used for producing salt.

 

Q.4. What is a lagoon? How does it differ from a lake?

Ans.  Lagoon is a stretch of brackish or salt water separated from the sea by a sandbank, bars, reefs,

etc. The action of wind and waves along coasts builds spits and bars in the inlets of seas isolating lagoons from the sea. They are commonly found off the deltas of large rivers like the Ganges, the Mahanadi, etc.

The Chilika lake of Orissa, the Pulicat lake of Tamil Nadu and the Kolleru lake of Andhra Pradesh are lagoons. Strong onshore winds are also capable of pushing the coastal sand dunes along beaches inland. They may enclose marshy lagoons.

(i)    Lagoons are found only in coastal areas, usually near the mouths of rivers, while lakes may be formed in any

geographical location, in highlands or on an inland basis.

(ii)   Lagoons have brackish water while a lake may have fresh water or salty water.

(iii) Lagoons are formed due to wind and wave action in the coasts. Lakes may be of tectonic origin or may be formed due to river action, glacial action, and wind. They may also be human-made artificial lakes.

 

Q.5. What is a gorge? In what type of terrain does a gorge form?

Ans. A gorge is a very steep sided, narrow river valley. It is found in the mountains in the upper courses of the rivers. They are near I-shaped in appearance.

In the upper course the river is very swift as it descends down the steep slopes of the mountains. Vertical corrosion or down cutting is the predominant action of the river here. In areas where the rocks are very hard or resistant, the valley that develops is narrow and the sides are steep, rising almost vertically. Such narrow river valleys are called gorges. Thus, gorges are found in mountainous terrain with resistant rocks. They are usually found in the upper reaches of the river in high mountains, e.g. the Indus Gorge, the Brahmaputra Gorge.

Gorges are features of youthful topography. In the Himalayas where the land has been uplifted in  recent geological periods, gorges are common.

 

Q.6.    What type of channel does the river Brahmaputra have? Write a short note on the formation of this type of channel.

Ans.  The river Brahmaputra has a braided channel in its entire length in Assam.

The north-eastern part of India is a region of high rainfall. Assam receives heavy rainfall during the monsoons. This increases the volume of water in the Brahmaputra river. On account of rapid erosion, the river carries a considerable amount of silt. The silt is deposited in the river- bed when the load becomes excessive. As a result the river splits into several complicated channels called braided channels. The channels frequently shift position. Many big and small river islands are located in between the braided channels. The Majuli Island on the Brahmaputra is the world’s largest, riverine island. It has, however, been broken due to floods.

 

Q.7.    Where are India’s most of the freshwater lakes located and why?

Ans.  Most of the freshwater lakes of India are located in the Himalayan region.

The lofty ranges of the Himalayas are snow covered and have many glaciers. Glacial activity results in the formation of circular hollows in the mountains. They are known as Cirques. The melting of the glacial snow in later periods forms  cirque lakes.

As the lakes have water from snow melt they are freshwater lakes, e.g., Pangong lake in Ladakh.

Tectonic activity in the Himalayan region also results in the formation of depressions. They are filled with melting snow, forming lakes of tectonic origin, e.g., the Wular Lake in Jammu and Kashmir, which is the largest freshwater lake in India.

The Dal Lake of Srinagar, Bhimtal and Nainital of Uttarakhand, Loktak Lake of Manipur and Barapani Lake of Meghalaya are some other important freshwater lakes. All are located in the Himalayan region and the Poorvanchal.

 

Q.8.    What is a river basin? Explain briefly.

The area drained by a single river system, comprising a main river and its tributaries, is called its drainage basin or river basin.The term drainage describes the river system of an area. Small streams flowing from different directions come together to form the main river. It has a number of tributaries and distributaries. The river ultimately drains into a large water body such as a lake or a sea or an ocean.

The area drained by the main river, its tributaries and distributaries is termed as the river basin. The river Ganga has the largest river basin in India. The river Indus has a larger river basin but most of it lies outside India.

 

Q.9.    Write a note on the river Krishna and its tributaries.

Ans. The river Krishna rises from a spring near Mahabaleshwar. It flows eastwards to the Bay of Bengal. It has a length of about 1400 km, which makes it the second longest river of Peninsular India after Godavari which has a length of 1500 km.

The Tungabhadra, the Koyna, the Bhima, the Ghataprabha and the Music are important tributaries of the river Krishna.The drainage basin of the river Krishna lies in Maharashtra, Karnataka and Andhra Pradesh.

 

Q.10.Name the three Himalayan river systems. Give two tributaries of each. 

Ans. Three Himalayan river systems are :

(I)   The Indus river system     (ii) The Ganga river system     (iii) The Brahmaputra river system. Tributaries  :

(i)Indus  river system  – Satluj,  Beas, Ravi      (ii) Ganga  river system  – Yamuna,Ghaghara, Gandak

(iii) Brahmaputra river system – Dibang,  Lohit, Kenula.

 

Q.11.What are the  differences  between  east-flowing  and  west-flowing  rivers  of  the  peninsular plateau?

Ans. The major rivers of the peninsular the Mahanadi, the Godavari, the Krishna etc. are flowing eastward and merges into the Bay of Bengal. Only the river Narmada and Tapti are flowing towards west and merge into the Arabian Sea. The essential differences between the two rivers are as follows

East-flowing Rivers

1. The east-flowing rivers have deltas at their mouths.

2. All rivers east-flowing drain into the Bay of Bengal.

3. All three rivers passed through a varied topography, i.e. hills, plains, plateaus etc.

4. Most rivers are fed by many east-west-flowing long tributaries.                                                                    

West-flowing Rivers

1. The west-flowing rivers do not have deltas at their mouths. They form estuaries.

2. All west-flowing rivers merge into the Arabian Sea.

3. These rivers flowed through the rift valley.

4. A few small tributaries joining at right angles are only found.

 

 

Q-12.What is the difference between tributary and the distributary? Write any three points.

Ans.  A smaller stream joining with the mainstream is known as tributary. A tributary is generally carried water and silt to the main river. River Jamuna is an example of a tributary of the river Ganga.

A Distributary is formed at the lower course of the river when the main channel of the river gets blocked with silt which forces the river to open branches. The Bhagirathi-Hooghly is a distributary of the river Ganga. The main function of the distributary is to distribute water through newly opened channels. The three basic differences between tributaries and distributaries are given below :

Tributary

1.    Tributaries can be found in three stages of the river – upper, middle and lower.

2.    It is useful for irrigation and transportation all through.

3.    It brings water and silt from its catchment area.

4.    Tributaries are fast-flowing.

Distributary

1. It is only found in lower courses of the river.    2. It only provides a network of transport in the lower course.

3. It deposits silt in its course.                                  4. Distributaries are slow-flowing.

     

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.

 

Write the salient features of the Ganga-Brahmaputra delta.

The salient features of the Ganga-Brahmaputra delta are :

• It is the largest delta of the world on the mouth of the Bay of Bengal.

• This has formed owing to the split of the Ganges and the Brahmaputra in several rivulets i.e., distributaries.

• Its lower portion is marshy owing to the messing up of the sea and the freshwater together.

• It is the most fertile and densely populated delta.

 

What are the major sources of river pollution?

The major source of river pollutants are :

• A heavy load of untreated sewage and industrial effluents are emptied into the river.

• The leakage of oil from ships.

• Excessive use of pesticides and chemical fertilizers.

Why are the Peninsular rivers not navigable?

Peninsular rivers are not navigable because :

• These all are seasonal rivers and generally dries up in summer.

• River beds are uneven, rocky and have sharp slopes.

• Construction of dams is difficult as a result of which navigation is not possible.

 

Describe some specific characteristics of the Brahmaputra river system.

Some specific characteristics of the Brahamputra river system are :

• It originates from Tibet and is slightly longer than the Indus.

• It carries a huge amount of silt.

• It flows parallel to the Himalayan Mountains in Tibet.

• It takes a ‘U’ turn at Namcha Barwa (height 7757 mts.) and enters Arunachal Pradesh.

 

Write a short note on the National River Conservation Plan (NRCP).

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 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 pollution abatement work.

How do the trellis and rectangular patterns of drainage develop? Trellis patterns : In the trellis pattern of drainage, the tributaries join the main river at approximately right angles and make it look like a rectangular arrangement. It develops where hard and soft rocks exist parallel to each other.

Rectangular patterns : This drainage pattern develops on a strongly jointed rocky terrain Trellis Drainage.

Which basin rises in the range of the Western Ghats.

• The Kaveri rises in the Brahmagiri range of the Western Ghats and it reaches the Bay of Bengal in the sojith 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.

Why are most of the freshwater lakes found in the Himalayan region?

Most of the freshwater lakes are found in the Himalayan region. They are of glacial origin. In other words, they 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 tectonic activity. It is the largest freshwater lake in India. The Dal lake, Bhimtal, Nainital, Loktak and Barapani are some other important freshwater lakes.

 

 

 

 

 

What is drainage and drainage basin?

Drainage: The term 'drainage' means the river system of an area. It is a system of flowing water from the higher level to the lower level. Drainage Basin : Some small streams flowing from different directions come together to form the main river, which ultimately drains into a large water body such as a lake or a sea. The area drained by a single river system is called a drainage basin.

 

Name the three Himalayan river systems. Give two tributaries of each.

 Three Himalayan river systems are :

• The Indus river system

• The Ganga river system

• The Brahmaputra river system.

Tributaries of the Himalayan rivers are :

• Indus river system – Satluj and Beas

• Ganga river system – Yamuna and Ghagra

• Brahmaputra river system – Dibang and Lohit.

 

How is Sundarban delta formed?

 When the Ganga flows eastwards till Farakka in West Bengal, here the river splits into the Bhagirathi-Hooghly (a distributary) flows southwards through the deltaic plains to the Bay of Bengal. The main stream 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 Sundarban Delta derived its name from the Sundari tree, which grows well in marshland. It is the world’s largest and fastest growing delta.

 

Mention some of the characteristics of the lakes.

India has many lakes. These differ from each other in 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 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.

 

From where does the river Ganga originate? Name the tributaries of the Ganga river.

Answer:

• The headwaters of the Ganga, called the ‘Bhagirathi’ is fed by the Gangotri Glacier,

• The Ganga is joined by many tributaries from the Himalayas, a few of them being major rivers, such as the Yamuna, the Ghaghara, the Gandak and the Kosi.

 

What are the different types of lakes found in India?

The types of lakes found in India.

• Freshwater lake : 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.

• Salt water lake : India’s famous salt water Lake is the Sambhar lake, found in Rajasthan. It is a salt water lake and its water is used for producing salt.

 

Which river is known as ‘Dakshin Ganga’? Describe its main features.

The Godavari river is known as the ‘Dakshin Ganga’.

The main features of the river Godavari are :

• It is the largest Peninsular river, which rises from the slopes of the Western Ghats in the Nasik district of Maharashtra.

• Its length is about 1500 km that drains into the Bay of Bengal.

• A number of tributaries join the Godavari river such as the Purna, the Wardha, the Penganga, the Manjra, the Wainganga, and the Pranhita.

 

Describe the three main features of the Narmada basin.

The river Narmada emerges from the Amarkantak hills in Madhya Pradesh.

The main features of the Narmada basin are :

(a) It flows towards the west in a rift valley formed due to faulting.

(b) It creates many picturesque locations like the Marble Rocks near Jabalpur and Dhuandhar Falls.

(c) All the tributaries of the Narmada are very short and most of them join the main stream at right angles. The Narmada Basin covers parts of Madhya Pradesh and Gujarat.

What is a lagoon? Which state of India is known for it?

 

• When a small portion of sea in the coastal areas is separated from the main body of water by sand bars of spits, a salt lake is formed. It is called a lagoon.

• These are found in Kerala and Odisha. The Chilka lake in Odisha is an example of a lagoon.

Drainage class 9 geography long question

Q.1. What are the differences between the Himalayan rivers and the Peninsular rivers? 

Ans.  The differences between the two main groups of rivers of India are as follows :

The Himalayan Rivers

1.     The Himalayan rivers are perennial in nature. They are fed by the melting snow and glaciers of the lofty ranges supplemented by monsoon rains. Hence, the rivers flow throughout the year.

2.     The Himalayan rivers have a long course from their sources in the mountains to the sea.

3.     The Himalayan rivers rise in the Himadri,  Himachal or Shivalik section of the Himalayas and form the Northern Plains with their deposition of alluvium.

4.     The Himalayan rivers flow through geologically unstable areas and are of uncertain nature.

5.     They perform intensive erosional activity in the upper course. In the middle and lower course they form meanders, oxbow lakes, extensive flood- plains and well developed deltas.

The Peninsular Rivers

1.   The Peninsular rivers are non-perennial in nature. They are fed by monsoon rains and         have    heavy flow during rainy season fol   lowered by reduced flow during the dry season. So they are seasonal rivers.

2.   The Peninsular rivers have shorter and shallower courses as compared to their Himalayan counterparts.

3.   Most of the rivers of Peninsular India originate in the Western Ghats and flow towards the Bay of Bengal. However, some of them originate in the Central Highlands and flow towards the west.

4.   Peninsular rivers originate at much lower altitudes and flow through geologically stable areas.

5.   The Narmada and Tapi are fault-guided rivers. The east-flowing rivers from large deltas. Meanders are not notable in these rivers.

 

Q.2. Write a note on the Indus Drainage System.

Ans.  The Indus  is one of the longest rivers of the world.

The river Indus rises in Tibet, near lake Mansarovar. Flowing west, it enters India in the Ladakh district of Jammu and Kashmir. A spectacular gorge formed by the Indus marks this part. Several tributaries – the Zaskar, the Nabra, the Shyok and the Hunza – join the Indus in the Kashmir region. The Indus flows through Baltistan and Gilgit and emerges from the mountains at Attock. The tributaries of the Indus – the Jhelum, the Chenab, the Ravi, the Beas and the Satluj – flow partly through Kashmir and Himachal Pradesh and mainly through Punjab.

They join together to enter the Indus near Mithankot in Pakistan. The Indus then flows southwards and eventually reaches the Arabian Sea, east of Karachi. The Indus has a total length of 2900 km. The Indus plain has a very gentle slope. A little over one third of the Indus basin lies in India in the states of Jammu and Kashmir, Himachal Pradesh and Punjab. Major part of its basin lies in Pakistan.

 

Q.3. Write a note on the Brahmaputra Drainage System.

Ans. The Brahmaputra is one of the longest rivers of the world, but most of its course lies outside India. The river Brahmaputra rises in Tibet east of the Mansarovar lake. The river flows eastwards parallel  to  the Himalayas in its upper course. It is known as Tsangpo in Tibet. Here it carries a smaller volume of water and less silt as it is a cold and dry area.

The river takes a ‘U’-turn bend at Namcha Barwa (7757 m) and enters India in Arunachal Pradesh through a gorge. In Arunachal Pradesh, it is known as Dihang. Here it is joined by the Dibang, the Lohit, the Kenula and many other tributaries.

The volume of the river increases and it is known as the Brahmaputra in Assam. The region receives heavy rainfall during the monsoon which increases the volume of water and silt content of the river.  Devastating floods are caused by the river in Assam and Bangladesh every year during the rainy season. The deposition of the silt in the riverbed due to the heavy load, leads to the formation of braided channels intervened by riverine islands.

The Brahmaputra has a braided channel in its entire length in Assam. Many riverine islands like the Majuli, the

world’s largest riverine island, are formed in between the channels.

The Brahmaputra is known as Jamuna in Bangladesh. Here it is joined by the Ganga, known here as Padma. Together they form the Ganga-Brahmaputra Delta known as Sunderbans, and discharge into the Bay of Bengal. 

 

Q.4.Write a note on the Ganga Drainage System.

Ans.  The Ganga is the longest and the most important river system of India. It  has a total length of over 2500 km. Nearly the entire river basin of the Ganga lies in India with a part of its lowerCourse and delta  in Bangladesh.

The headwaters of the Ganga are called the ‘Bhagirathi’. It is fed by the Gangotri Glacier. It is joined by the Alaknanda at Devprayag in Uttarakhand. At Haridwar, the Ganga emerges from the mountains and enters the plains. The Ganga is joined by a large number of tributaries.

The Yamuna, a right-bank tributary of the Ganga, rises from the Yamunotri Glacier, flows parallel to the Ganga and joins it at Allahabad. The Ghaghra, the Gandak, the Kosi and the Sarda are the left-bank tributaries of the Ganga.

The other right bank tributaries of the Ganga – the Chambal, the Betwa and the Son come from the peninsular uplands. The Ganga and its tributaries form a major portion of the northern plains.

On account of water availability and fertile soil, it is the most important agricultural region of India. The Ganga develops large meanders in the plains.

The Ganga flows eastwards with the increased volume up to Farakka in West Bengal. The river bifurcates here. Its distributary, the Bhagirathi-Hooghly, flows through the deltaic plains to the Bay of Bengal.

The mainstream flows southwards into Bangladesh. Here it is known as Padma. It is joined by the Brahmaputra. Further downstream it is known as Meghna. Together they form the Ganga- Brahmaputra Delta, also known as Sunderbans delta. It is the world’s largest and fastest growing delta.

 

Q.5.Write a note on the east-flowing and the west-flowing rivers of Peninsular India.

Ans. The Peninsular Plateau of India is marked by a large number of east-flowing rivers and a few west-flowing rivers.  Most of the major rivers of Peninsular India such as the Mahanadi, the Godavari, the Krishna and the Kaveri and their tributaries flow eastwards.  They rise from the Western Ghats, the highlands of the Deccan Plateau, flow towards east and drain into the Bay of Bengal.

Only two big rivers, the Narmada and the Tapi, with long courses flow westwards in the Peninsular Plateau region. They rise from the Satpura range and Amarkantak hills, flow westwards through faults and drain into the Arabian Sea.

The coastal plains between Western Ghats and the Arabian Sea are very narrow. Hence, the west-flowing coastal rivers are short and swift flowing. The Sabarmati, Mahi, Bharathpuzha and Periyar are the west-flowing rivers. The Sabarmati and the Mahi originate in the Central highlands and flow into the Arabian Sea.

The Western Ghats form the main water divide in Peninsular India. The east-flowing rivers have wide basins. They have dendritic drainage patterns with  many tributaries joining them.  They form large deltas at their mouths.

The west-flowing rivers flow between highlands and have elongated courses. They have trellis and rectangular drainage patterns. They flow through rift valleys and are fault guided rivers. They form estuaries at their mouths. The west-flowing rivers do not form deltas.

 

Why are the rivers considered as the lifeline of human civilization?

Answer:

The Rivers are considered as the lifeline of human civilization because of the following reasons.

• Abundant Supply of Drinking Water : The rivers and lakes fulfill the basic need of all living beings including human beings.

• Water for Irrigation : Rivers are the main source of irrigation. :

• Navigation : Rivers are the cost-free means of water transportation of goods and people from one place to another.

• Biologically Productive Areas : Most of the estuaries formed at the meeting point of freshwater and saline water of the sea. These are found in the most suitable places for fish breeding.

• Source of Generation of Hydro-Power : Rivers are an abundant source of generating electricity. Large dams have been built for this purpose.

 

Define the term drainage? What are the different types of drainage patterns?

Answer:

The term drainage describes the river system of an area. 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.

The different drainage patterns are :

• Dendritic Pattern : The dendritic pattern develops where the river channel follows the slope of the terrain. The stream with its tributaries resembles the branches of a tree, thus the name dendritic.

• Trellis Pattern : A river joined by its tributaries, at approximately right angles, develops a trellis pattern. A trellis drainage pattern develops where hard and soft rocks exist parallel to each other.

• Rectangular Pattern : A rectangular drainage pattern develops on a strongly jointed rocky terrain.

• Radial Pattern : The radial pattern develops when streams flow in different directions from a central peak or dome like structure.

 

What do you know about the Ganga River System?

Answer:

The Ganga System : The Ganga acquires its name after its two head streams—the Alaknanda and the Bhagirathi join at Devprayag. The Ganga enters the plains from the Himalayas at Haridwar. It is joined by a large number of tributaries from the north. Among them the Ghaghara, the Gandak, and the Kosi enter the northern plains of India from Nepal. They are the rivers which flood parts of the northern plains every year, causing widespread damage to life, whereas they enrich the soil for agricultural use. These rivers have tremendous potential to generate waterpower and to irrigate lands both in Nepal and India. By mutual trust and cooperation, the sharing of river water for developmental purposes can be used in prosperity to the people of both the countries. The main tributaries, which come from the peninsular uplands, are the Chambal, the Betwa and the son.

The length of the Ganga is over 2,500 km. In India, it has the largest basin. The Ganga river system drains most of north India.

 

Write a note on the Brahmaputra Drainage System.

Answer:

The river Brahmaputra rises in Tibet, east of the Mansarovar lake. The river flows eastwards parallel to the Himalayas in its upper course. It is known as TsangPo in Tibet. It carries a smaller volume of water and less silt in Tibet as it is a cold and dry area.

The river takes a U-turn bend at Namcha Barwa (7757 m) and enters India in Arunachal Pradesh through a gorge. In Arunachal Pradesh, it is known as Dihang. Here, it is joined by the Dibang, the Lohit, the Kenula and many other tributaries. The volume of the river increases here, and it is known as the Brahmaputra in Assam.

The region receives heavy rainfall during the monsoon which increases the volume of water and silt content of the river. Devastating floods are caused by the river in Assam and Bangladesh every year during the rainy season. The deposition of the silt in the riverbed due to the heavy load, leads to the formation of braided channels intervened by riverine islands.

The Brahmaputra has a braided channel in its entire length in Assam. Many rivers . islands like the Majuli, the world’s largest riverine island, are formed in between the channels. The Brahmaputra is known as Jamuna in Bangladesh.

 

In what different ways do rivers get polluted?

Answer:

Rivers get polluted in the following ways :

• The growing domestic, municipal, industrial and agricultural demand for water from rivers naturally affects the quality of water.

• The volume of the river is also reduced because more and more water is being drained out of the rivers.

• 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.

• The increasing urbanization and industrialisation also contribute to river pollution.

• Dumping of garbage into the streams is another cause of river pollution. They are changing the life-giving rivers into toxic streams.