NCERT Solutions for class 9 SST Geography Chapter 3 Drainage Questions (Updated for 2021 – 22)

Drainage Class 9 Extra Questions Very Short Answer Type Questions

Question 1.
The area drained by a single river system is called a _______ .
Answer:
Drainage

Question 2.
The world’s largest drainage basin is of the river _______ .
Answer:
Amazon

Question 3.
The largest delta in the world is _______ .
Answer:
Sunderban delta

Question 4.
An area through which a river and its tributaries flow is called _______ .
Answer:
Basin

Question 5.
What is the total length of the Indus river?
Answer:
The total length of the Indus river is 2900 km.

Question 6.
Which is the largest tributary of the Ganga?
Answer:
Yamuna

Question 7.
Most of the Himalayan rivers are _______ .
Answer:
Perennial

Question 8.
A river along with its tributaries may be called
Answer:
River system

Question 9.
The Brahmaputra rises in _______ .
Answer:
Tibet

Question 10.
Name any one freshwater lake of India.
Answer:
Wular lake.

Question 11.
When the streams flow in different directions from a central peak or dome like structure, a _______ pattern is developed.
Answer:
Radial drainage.

Question 12.
What does NRCP stands for?
Answer:
National River Conservation Plan

Question 13.
What controls the drainage systems of India?
Answer:
The board relief features of the subcontinent control the drainage system of India.

Question 14.
The Ganga Action Plan (GAP) Phase – I started in the year _______ .
Answer:
1985

Question 15.
Which state is not drained by the Godavari river?
Answer:
Andhra Pradesh

Question 16.
The Narmada Basin creates many picturesque locations. Name two of them.
Answer:

• The ‘Marble rocks’ near Jabalpur.
• The ‘Dhuadhar falls’.

Question 17.
What is common between river Damodar and the river Kosi?
Answer:
Both of these rivers are considered as “Rivers of Sorrow”. They cause flood every year and cause destruction of life and property.

Question 18.
The river Brahmaputra is known as the Tsang Po in Tibet and _______ in Bangladesh.
Answer:
Jamuna

Question 19.
The Sundarban delta is the home of which animal?
Answer:
Royal Bengal Tiger

Question 20.
Most of the freshwater lakes are in the _______ .
Answer:
Himalayan region

Question 21.
Which is the largest peninsular river?
Answer:
The Godavari is the largest peninsular river.

Question 22.
Name some freshwater lakes of India.
Answer:
The Wular lake, the Dal lake, Bhimtal, Nainital, Loktak and Barapani.

Question 23.
Which city is located on the water divide between the Indus and the Ganga river systems?
Answer:
Ambala city is located on the water divide between the Indus and the Ganga river systems.

Question 24.
Mention the course of the river Mahanadi.
Answer:
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 Odhisha.

Question 25.
Write a short note on the Krishna Basin.
Answer:
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 Maharashtra, Karnataka and Andhra Pradesh.

Drainage Class 9 Extra Questions Short Answer Type Questions

Question 1.
Give an account of the Tapi Basin.
Answer:
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.

Question 2.
Write the salient features of the Ganga-Brahmaputra delta.
Answer:
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 split of the Ganges and the Brahmaputra in several rivulets i.e., distributaries.
• Its lower portion is marshy owing to mess up of the sea and the freshwater together.
• It is the most fertile and densely populated delta.

Question 3.
What are the major sources of river pollution?
Answer:
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 fertilisers.

Question 4.
Why are the Peninsular rivers not navigable?
Answer:
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.

Question 5.
Describe some specific characteristics of the Brahmaputra river system.
Answer:
Some specific characteristics of the Brahamputra river system are :

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

Question 6.
Write a short note on National River Conservation Plan (NRCP).
Answer:
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 pollution abatement work.

How does 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.

Question 9.
Which basin rises in the range of the Western Ghats.
Answer:

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

Question 10.
Why are most of the freshwater lakes found in the Himalayan region?
Answer:
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 the tectonic activity. It is the largest freshwater lake in India. The Dal lake, Bhimtal, Nainital, Loktak and Barapani are some other important freshwater lakes.

Question 11.
What is drainage and drainage basin?
Answer:
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.

Question 12.
Name the three Himalayan river systems. Give two tributaries of each.
Answer:
Three Himalayan river systems are :

• The Indus river system
• The Ganga river system
• The Brahamaputra river system.

Tributaries of the Himalayan rivers are :

• Indus river system – Satluj and Beas
• Ganga river system – Yamuna and Ghaghara
• Brahmaputra river system – Dibang and Lohit.

Question 13.
How is Sundarban delta formed?
Answer:
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.

Question 14.
Mention some of the characteristics of the lakes.
Answer:
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.

Question 15.
From where does the river Ganga originates? Name the tributaries of the 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.

Question 16.
What are the different types of lakes found in India?
Answer:
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.

Question 17.
Which river is known as ‘Dakshin Ganga’? Describe its main features.
Answer:
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 joins the Godavari river such as the Purna, the Wardha, the Penganga, the Manjra, the Wainganga, and the Pranhita.

Question 18.
Describe the three main features of the Narmada basin.
Answer:
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 location 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.

Question 19.
What is a lagoon? Which state of India is known for it?
Answer:

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

Drainage Class 9 Extra Questions Long Answer Type Questions

Question 1.
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 being 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.

Question 2.
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.

Question 3.
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 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.

Question 4.
Write a note on the Brahmaputra Drainage System.
Answer:
The river Brahmaputra rises in Tibet, east of the Mansarowar lake. The river flows eastwards parallel to the Himalayas in its upper course. It is known as Tsang Po in Tibet. It carries smaller volume of water and less silt in Tibet as it is a cold and a 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 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.

Question 5.
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 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 urbanisation and industrialisation also contribute to the river pollution.
• Dumping of garbage into the streams is another cause of river pollution. They are changing the life-giving rivers into toxic streams.