Important Questions for Chapter 3 Drainage Class 9 Geography
Important Questions1
Which word denotes a river system of an area?
Answer
Drainage
VSAQ
2
Which river is known as the ‘Dakshin Ganga’?
Answer
The Godavari
VSAQ
3
Which is the second longest river of Peninsular India?
Answer
Krishna.
VSAQ
4
Which place is located on the water divide between the Indus and the Ganga river system ?
Answer
Ambala.
VSAQ
5
Which type of drainage pattern is made by Narmada River?
Answer
Trellis drainage pattern.
VSAQ
6
Zaskar and Nubra are important tributaries of which river?
Answer
Indus river.
VSAQ
7
At which place do the Satluj, Beas, Ravi, Chenab and the Jhelum rivers going together with Indus ?
Answer
Mithankot.
VSAQ
8
Yamuna, Ghaghara and Kizi are important tributaries of which river?
Answer
Ganga.
VSAQ
9
According to Indus Water Treaty (1960), India can use how much percentage of total water carried by Indus?
Answer
20% of total water carried by Indus.
VSAQ
10
In which of the following states is Sambhar Lake situated?
Answer
Rajasthan.
VSAQ
11
Which is the first state to welcome river Brahmaputra in India?
Answer
Arunachal Pradesh.
VSAQ
12
Which kind of a drainage pattern is formed when tributaries join rivers at almost right angles?
Answer
Trellis drainage.
VSAQ
13
Which is the largest river basin in India?
Answer
The Ganga river basin.
VSAQ
14
Which river flows through a rift valley?
Answer
The Narmada and Tapi rivers.
VSAQ
15
The River Mahanadi rises from which state?
Answer
Chhattisgarh.
VSAQ
16
Which is the point of origin of the River Krishna?
Answer
Mahabaleshwar.
VSAQ
17
Which tributary of Ganga came from the peninsular uplands?
Answer
Son.
VSAQ
18
In which state does the largest part of the Godavari basin lie?
Answer
Maharashtra.
VSAQ
19
Which one of the following drainage patterns develops on a strongly jointed rocky terrain?
Answer
Rectangular.
VSAQ
20
Which two Peninsular rivers flow through a trough?
Answer
The Narmadi and Tapi.
VSAQ
21
Which is the largest salt-water lake in India?
Answer
Lake Chilika.
VSAQ
22
What is an area drained by a single river system called?
Answer
Drainage basin.
VSAQ
23
Which of the following describes drainage patterns resembling branches of a tree?
Answer
Dendritic.
VSAQ
24
Which is the largest freshwater lake in India?
Answer
Wular Lake.
VSAQ
1
Explain the term ’water divide’ with example. What is its significance?
Answer
Any elevated area such as a mountain or an upland that separates two drainage basins is known as water divide. The Western Ghats is a water divide of peninsular rivers.
It helps us identify two different drainage patterns.
SAQ
2
What are perennial and non-perennial rivers? Give reasons why the Himalayan region consists of perennial rivers.
Answer
The rivers that flow throughout the year are termed as perennial rivers. They have more or less even flow throughout the year. Example: the Ganga. 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. Example: the Subarnarekha. 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.
SAQ
3
What is a river pattern? Name any four patterns formed by the river.
Answer
The stream 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. Four patterns formed by rivers are:
(i) Dendritic pattern
(ii) Trellis pattern
(iii) Radial pattern
(iv) Rectangular pattern.
SAQ
4
Name the three Himalayan river system. Give two tributaries of each.
Answer
Three Himalayan river systems are :
• The Indus river system
• The Ganga river system
• The Brahamaputra river system.
Tributaries:
• Indus river system – Satluj, Beas, Ravi
• Ganga river system – Yamuna, Ghaghara, Gandak
• Brahmaputra river system – Dibang, Lohit, Kenula.
SAQ
5
Define a river system and describe two characteristics of river Indus.
Answer
A river along with its tributaries is called a river system. Characteristics:
• River Indus rises in Tibet near Mansarovar Lake.
• Its total length is 2,900 km and is one of the longest rivers of the world.
• Majority of it flows through Pakistan and assists in agricultural activities.
SAQ
6
Describe any three features of the Himalayan Rivers.
Answer
Features:
• These are perennial.
• Have long courses from their source to the sea.
• These rivers perform intensive erosion activity in their upper course and carry huge load of silt and sand.
SAQ
7
Describe any three important features of the Ganga river system.
Answer
• Headwaters of the Ganga (called Bhagirathi) is born from Gangotri Glacier and is joined by Alakananda at Devprayag.
• The Ganga is joined by a large number of tributaries from east and west.
• It drains into the Bay of Bengal after joining the Brahmaputra and through its distributaries.
SAQ
8
How do the Himalayan rivers perform erosional activities and form depositional features?
Answer
• In the upper course, rivers flow with great speed from higher to lower levels. They cause erosion.
• In the middle and the lower course, they carry lots of sediment like silt and sand. So, the speed slows down.
• Besides, absence of slope in the lower course causes deposition and formation of various features.
SAQ
9
What is a lake? How are lakes formed?
Answer
A lake is an area of water surrounded by land on all sides.
• There are lakes which are formed as a result of action of glaciers and ice sheets, while the others have been formed by wind, river action, and human activities.
• Some lakes are formed as a result of the tectonic activity. For example, Wular Lake in Jammu and Kashmir.
• The damming of rivers for the generation of hydel power has also led to the formation of lakes.
SAQ
10
Differentiate between the Ganga and the Godavari river system.
Answer
Ganga River System:
• It is a Himalayan river.
• The ganga emerges from the mountains onto the plains from Haridwar.
• The length of Ganga is over 2500 km. Godavari river system:
• It is a peninsular river.
• It rises from the slopes of the Western Ghats in Nasik district of Maharashtra.
• The length of Godavari is 1500 km.
SAQ
11
Explain any three differences between east flowing peninsular rivers and west flowing peninsular rivers.
Answer
The East flowing rivers:
• These rivers originate from the Western Ghats and flow eastwards.
• They all form deltas at their mouths.
• They drain into the Bay of Bengal.
• They have large volume of water. Examples: Mahanadi, Godavari, Krishna and Kaveri.
The West flowing rivers:
• These rivers originate in Central India and flow westwards.
• They form estuaries since they flow from rift valleys.
• They drain into the Arabian Sea.
• They have lesser volume of water. Examples: Narmada and Tapi.
SAQ
12
Explain any three main features of the Brahmaputra river system.
Answer
Characteristics of the Brahmaputra river system:
• The Brahmaputra rises in Tibet, flows eastwards parallel to the Himalayas and enters India in the state of Arunachal Pradesh.
• At this point, it is joined by Dibang and Lohit.
• It has a braided channel in Assam and forms many riverine islands.
SAQ
13
Why are lakes of great value to human beings? Explain any three reasons.
Answer
Lakes are of great value to human beings.
• A lake helps to regulate the flow of a river. During heavy rainfall, it prevents flooding. During dry reason, it helps to maintain an even flow of water.
• Lakes are also used for developing hydel power.
• Lakes helps in developing tourism and provide recreation.
SAQ
14
In which state of India, river Brahmaputra has a braided channel in its entire length? Why does this river carry a large volume of water and silt in India compared to Tibet?
Answer
The Brahmaputra has a braided channel in its entire length in the state of Assam. This river carries a larger volume of water and silt in India, as in this area, it passes through a region of high rainfall, whereas, in Tibet, the river carries a smaller volume of water and less silt, as it is a cold and dry area.
SAQ
15
Describe any three important features of the Mahanadi Basin.
Answer
• The Mahanadi rises in Chhattisgarh.
• It flows through Odisha, for 860 km till it falls into the Bay of Bengal.
• Its basin is shared by Maharashtra, Chhattisgarh, Jharkhand and Odisha.
SAQ
16
Which river is known as the Dakshin Ganga? State any two characteristics of it.
Answer
The Godavari.
Characteristics are:
• It rises from the slopes of the Western Ghats in Nashik district of Maharashtra.
• Length is about 1,500 km.
• The basin covers Maharashtra, Madhya Pradesh, Odisha and Andhra Pradesh.
SAQ
17
Distinguish between delta and estuary.
Answer
Delta:
• These are triangular deposits made by rivers at their mouth.
• They are formed in the regions of low tides.
• These are agriculturally fertile lands.
Estuary:
• These are sharp edged mouths of rivers without any deposits.
• They are formed in the region of high tides and rift valleys.
• These are agriculturally not so fertile.
SAQ
18
Why is the Godavari River also known as ‘Dakshin Ganga’?
Answer
The Godavari River is known as ‘Dakshin Ganga’ because:
• The Godavari is the second largest river in India and the largest river in southern India.
• The river covers a large numbers of states as the Ganga does.
• The Godavari is considered sacred and important like Ganga.
SAQ
19
Where does the Narmada River originate from? Name any two picturesque locations formed by it.
Answer
The Narmada River originates from the Amarkantak Hills in Madhya Pradesh.
• It flows towards the west in a rift valley formed due to faulting. Picturesque locations:
• The Marble Rocks near Jabalpur where the Narmada flows through a deep gorge.
• The Dhuadhar Falls, where the river plunges over steep rocks.
SAQ
20
Why are Peninsular rivers seasonal in nature? State any three reasons.
Answer
• The peninsular rivers are rain fed and depend only on rain water. These rivers do not get continuous water supply from glaciers. Hence, most of the rivers dry up in hot summer season.
• These rivers have small basins and catchment areas. This is also the reason that the peninsular rivers are seasonal in nature.
• The peninsular rivers lie in medium to low rainfall regions when compared to Himalayan rivers, so they receive less rain water in the monsoon season.
SAQ
21
Describe any three features of peninsular rivers.
Answer
Features:
• Most of the Peninsular rivers drain into the Bay of Bengal.
• These rivers make deltas at their mouth.
• The Narmada and Tapi are the only rivers which make estuaries.
• Drainage basin is comparatively small.
SAQ
22
Why and how are man-made lakes created? Give an example.
Answer
Causes of creating Man-Made lakes:
• Man-made lakes are created for hydro-electric power supply, recreational purposes, industrial use, agricultural use or domestic water supply.
• Lakes are formed by stopping the natural flow of river by constructing dams resulting into collection of water on one side. The Guru Gobind Sagar Lake is an example of manmade lake.
SAQ
23
How does a man-made lake help a river to regulate its flow?
Answer
Man-made lakes help a river to regulate its flow in the following manner:
• Man-made lakes are generally created by construction of dams.
• The reservoirs thus created help to control the flow of the rivers.
• They help in regulating the flow of water to be released to downstream regions as per the requirement.
SAQ
24
Explain any three significance of rivers for the economy of a country.
Answer
Rivers are considered significant for the economy of the country:
• They provide water for irrigation.
• They are used for hydro-power generation.
• They are used for navigation and tourism.
SAQ
25
“Rivers have been of fundamental importance throughout the human history.” Justify this statement in three points.
Answer
Rivers have been of fundamental importance throughout the human history:
• Water is a basic natural resource, essential for various human activities.
• Therefore, river banks attracted settlers since ancient times. These settlements have now become big cities.
• Use of rivers has been taking place for irrigation, navigation and trade since ages.
SAQ
26
What is self-cleansing capacity of a river? How does it get affected by pollution?
Answer
• A fast flowing river with lots of volume of water can dilute pollution load which is known as the self- cleansing capacity of the river.
• Pollution slows the speed of rivers affecting self cleansing capacity of the river.
• Pollution increases the volume of load in the river.
SAQ
27
Explain any three causes of river pollution in India.
Answer
Three causes of river pollution are:
• Increasing urbanization and industrialization. A heavy load of untreated sewers and industrial effluents further increases river pollution.
• Growing domestic, industrial and agricultural demand for water affects the quality of water in the rivers.
SAQ
28
What is the difference between tributary and the distributary?
Answer
Tributary:
• Tributaries can be found in three stages of the river – upper, middle and lower.
• It is useful for irrigation and transportation.
• It brings water and silt from its catchment area.
Distributary:
• It is only found in lower coarses of the river.
• It only provides a network of transport in the lower course.
• It deposits silt in its coarse.
SAQ
1
Define water divide. What are the different patterns of flow made by a river?
Answer
An elevated area such as a mountain or an upland that separates two drainage basins is called water divide. The four drainage patterns are as follows:
• Dendritic: The dendritic pattern develops where the river channels follow the slope of the terrain. The stream with its tributaries resembles the branches of a tree, thus the name dendritic.
• Trellis: 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: A rectangular drainage pattern develops on a strongly-jointed rocky terrain.
• Radial: The radial pattern develops when streams flow in different directions from a central peak or dome-like structure.
LAQ
2
What are the differences between the Himalayan rivers and the Peninsular rivers?
Answer
The Himalayan Rivers:
• The Himalayan rivers are perennial in nature as they are fed by the melting snow and glaciers of the lofty ranges supplemented by monsoon rains.
• The Himalayan rivers have long course from their sources in the mountains to the sea.
• The Himalayan rivers rise in the Himadri, Himachal or Shivalik section of the Himalayas and form the Northern Plains with their deposition of alluvium.
• The Himalayan rivers flow through geologically unstable areas.
• They perform intensive erosional activity in upper course. In middle and lower course they form meanders, oxbow lakes, extensive flood- plains and well developed deltas.
The peninsular rivers:
• The Peninsular rivers are non-perennial in nature as they are fed by monsoon rains and have heavy flow during rainy season followed by reduced flow during dry season.
• The Peninsular rivers have shorter and shallower courses.
• Most of the rivers of Peninsular India originate in the Western Ghats and flow towards the Bay of Bengal.
• Peninsular rivers originate at much lower altitudes and flow through geologically stable areas.
• The Narmada and Tapi are fault-guided rivers. The east-flowing rivers from large deltas. Meanders are not notable in these rivers.
LAQ
3
Describe the Indus river system from origin point to ocean meeting point in brief.
Answer
The main features of the Indus river system are as given below:
• With a total length of 2,900 kms, the Indus is one of the longest rivers of the world.
• The Indus originates from a peak nearby the Mansarover Lake in the Kailash range of Greater Himalayas.
• It flows down from an altitude of 5,000 m from the sea level.
• Then it enters the Ladakh district of Jammu and Kashmir where it forms a striking gorge. Several tributaries like Zaskar, Nubra, Shyok and Hunza join it in the Kashmir region.
• The Indus then flows through Baltistan into Gilgit and emerges from the mountains at Attock.
• The Satluj, Beas, Ravi, Chenab and Jhelum join together to enter the Indus near Mithankot in Pakistan.
• Eventually, it reaches the Arabian Sea, east of Karachi.
LAQ
4
What is water pollution? Describe the main sources of pollution in the river Ganga.
Answer
When any unwanted waste material is added to water which makes it poisonous and useless, we call it water pollution. Main sources of pollution in the River Ganga:
• Industrial effluents.
• Disposal of sewage of urban centres.
• Sewage, garbage and liquid waste of households agricultural lands and factories discharged into the river.
• Disposal of thermal power plants.
LAQ
5
Why are rivers important for a country's economy?
Answer
• The rivers form broad, fertile alluvial plains that have been the cradle of human civilisation.
• Water from the river is a basic natural resource, essential for various human activities. They provide water for domestic use.
• Rivers provide water for irrigation that helps to develop agriculture in the surrounding area.
• Rivers supply water for industrial use.
• Rivers provide for a cheap mode of transportation, inland navigation.
• Hydro-electricity harnessed from river water that supplies power to industries and houses.
• Also used for fishing and recreation.
LAQ
6
Mention the main features of the Ganga Action Plan.
Answer
Main features of the Ganga Action Plan:
• Sewage flowing into the river is to be diverted to other locations for treatment and conversion into energy source.
• Steps have been taken to supply safe drinking water by constructing electric crematoriums and separating bathing Ghats.
• The diversion of several major drains carrying wastes into the river has been completed in cities like Varanasi, Patna and Kanpur and pollution level has been decreased.
• Infrastructure capable of diverting and treatment 835 million litres per day of domestic waste or sewage has been created.
• The Ganga Action Plan has been merged with National River Conservation Plan. It now covers 152 towns located along 27 Inter-state rivers in over 16 states.
LAQ