Drainage Class 9 Important Questions Very Short Answer Type Questions

Question 1.
What is a drainage?
Year of Question :(2012)

Answer: A system of flowing water from the higher level to the lower level

Question 2.
What is the area drained by a single river system called?
Year of Question :(2017)

Answer: Drainage basin

Question 3.
What are the different patterns formed by the streams?
Year of Question :(2012)

Answer:

• Dendritic
• Trellis
• Radial

Question 4.
Name the two main drainage basins?
Year of Question :(2015)

Answer:

• The Indus Basin
• The Ganga-Brahmaputra Basin

Question 5.
Which type of drainage pattern does an area have where hard and soft rocks exist parallel to each other?
Year of Question :(2019)

Answer: Trellis pattern

Question 6.
What is a drainage river basin?
Year of Question :(2010)

Answer: The area drained by a single river system is called a river basin or a drainage basin

Question 7.
What is meant by watershed or a water divide?
Year of Question :(2012)

Answer:The upland or a mountain which separates two adjoining drainage basins is known as a watershed or a water divide, e.g., Ambala

Question 8.
On what does the stream within a drainage basin depend?
Year of Question :(2010)

Answer:

• Relief
• Geological structure
• Climatic conditions of the area

Question 9.
Which is the main water divide in southern India?
Year of Question :(2012)

Answer: Western Ghats

Question 10.
Zaskar and Nubra are important tributaries of which river?
Year of Question :(2011)

Answer: Indus river

Question 11.
Name the three main Himalayan river systems?
Year of Question :(2019)

Answer:

• The Indus River System
• The Ganga River System
• The Brahmaputra River System

Question 12.
What is a gorge? HOTS?
Year of Question :(2012)

Answer: A deep narrow opening formed by the river in the upper course, e.g., the gorge formed by the river Indus

Question 13.
Name three depositional features formed by the Himalayan rivers?
Year of Question :(2013)

Answer:

• Flood plains
• River cliffs
• Levee

Question 14.
Name any four depositional features of the Himalayan rivers in their middle and lower course?
Year of Question :(2012)

Answer:

• Meanders
• Oxbow lakes
• Delta
• Flood plains

Question 15.
Where does the river Indus rise?
Year of Question :(2018)

Answer: In Tibet, near the Mansarovar lake

Question 16.
Name the tributaries of river Indus?
Year of Question :(2012)

Answer: The Zaskar, the Shyok, the Nubra and the Hunza

Question 17.
Name the two main groups into which the river systems of India are classified?
Year of Question :(2012)

Answer:

• The Himalayan rivers
• The Peninsular rivers

Question 18.
Why are the Himalayan rivers perennial?
Year of Question :(2010)

Answer:

• Most of the Himalayan rivers originate from the glaciers
• They get water from the rainfall as well as from the glaciers

Question 19.
Name the city located on the water divide between the Indus and the Ganga river systems?
Year of Question :(2018)

Answer: Ambala.

Question 20.
Which states are benefited by the Indus system?
Year of Question :(2011)

Answer: Punjab, Haryana and western parts of Rajasthan

Question 21.
What is the Indus water treaty?
Year of Question :(2012)

Answer: It is a treaty signed between India and Pakistan. According to this treaty, India can use only 20% of the total water carried by the Indus river system

Question 22.
Name the plan which was launched to reduce pollution in the river Ganga?
Year of Question :(2017)

Answer: The Ganga Action Plan

Question 23.
Name any two tributaries of Ganga which rise in the Nepal Himalayas?
Year of Question :(2012)

Answer: The Ghaghara and Kosi

Question 24.
Which is the northernmost point of the Ganga Delta?
Year of Question :(2012)

Answer: The Ganga flows eastwards til Farakka in West Bengal. This is the northernmost point of the Ganga delta

Question 25.
Which is the largest river basin in India??
Year of Question :(2013)

Answer: The Ganga Basin

Question 26.
What is the length of the Ganga?
Year of Question :(2014)

Answer: About 2500 km

Question 27.
Name two headstreams of the Ganga. Where do they unite?
Year of Question :(2015)

Answer:

• Bhagirathi
• Alaknanda
• They meet at Devprayag

Question 28.
Name the city at which the Ganga enters the plains from the Himalayas?
Year of Question :(2016)

Answer: Haridwar

Question 29.
Name the tributaries of river Ganga which enter the northern plains from Nepal?
Year of Question :(2017)

Answer: Ghaghara, Gandak and Kosi

Question 30.
Name the two main right bank tributaries of the Ganga?
Year of Question :(2012)

Answer: The Yamuna and the Son

Question 31.
What is the major concern of the Ganga Action Plan?
Year of Question :(2018)

Answer: Rising pollution in the Ganga is the major concern of the Ganga Action Plan

Question 32.
What is the name of the Brahmaputra river in Tibet?
Year of Question :(2012)

Answer: Tsangpo

Question 33.
From where does the river Brahmaputra arise?
Year of Question :(2011)

Answer: In Tibet east of Mansarover lake

Question 34.
What are perennial rivers?
Year of Question :(2011)

Answer: The rivers which have water throughout the year are called the perennial rivers

Question 35.
Which is the largest Peninsular river? Where does it originate from?
Year of Question :(2012)

Answer: Godavari, it arises from the Nasik district of Maharashtra

Question 36.
Name any two Peninsular rivers which flow through the rift valley?
Year of Question :(2019)

Answer: The Narmada and the Tapti

Question 37.
Which is the main watershed in Peninsular India?
Year of Question :(2017)

Answer: The main watershed in Peninsular India is formed by the Western Ghats

Question 38.
Name the major rivers of the Peninsular India?
Year of Question :(2010)

Answer: The Mahanadi, the Godavari, the Krishna and the Kaveri

Question 39.
Name any two small river basins of the peninsular region?
Year of Question :(2011)

Answer:

• The Pennar
• The Mahi

Question 40.
Name two large rivers of India which flow into the Arabian Sea?
Year of Question :(2019)

Answer: The Narmada apd the Tapti

Question 41.
Which type of drainage pattern is made by Narmada river?
Year of Question :(2012)

Answer: Trellis

Question 42.
What is the msyor reason for the nonperennial nature of the peninsular rivers?
Year of Question :(2012)

Answer: Rainfall is the only source of water for these rivers

Question 43.
From where does the Narmada river rise?
Year of Question :(2019)

Answer: Near Amarkantak, in Madhya Pradesh

Question 44.
In which hills does the Tapi river rise?
Year of Question :(2012)

Answer: Satpura ranges

Question 45.
From where does the Tapti river arise?
Year of Question :(2012)

Answer: In the Betul district of Madhya Pradesh

Question 46.
Name the states through which the Tapti river flows?
Year of Question :(2012)

Answer: Madhya Pradesh, Gujarat and Maharashtra

Question 47.
In which state does the largest part of the Godavari basin lie?
Year of Question :(2012)

Answer: Maharashtra

Question 48.
Which river is known as Dakshin Ganga?
Year of Question :(2012)

Answer: Godavari

Question 49.
Name the tributaries of Godavari river?
Year of Question :(2016)

Answer: The Purna, the Wardha, the Pranhita, the Manjra, the Wainganga and the Pehganga

Question 50.
Why is the Godavari river called the Vridha Ganga or the Dakshin Ganga?
Year of Question :(2012)

Answer: It is because of its large size and the huge extent

Question 51.
Name the tributaries of Krishna?
Year of Question :(2019)

Answer: The Tungabhadra, the Koyna, the Ghatprabha, the Musi and the Bhima

Question 52.
What is the source of river Yamuna?
Year of Question :(2012)

Answer: Yamunotri glacier in the Himalayas

Question 53.
Which city is located at the confluence of the Yamuna and the Ganga?
Year of Question :(2012)

Answer: Allahabad

Question 54.
Name the five rivers of Punjab from which the water falls into the Indus?
Year of Question :(2017)

Answer: The Sutlej, the Beas, the Ravi, the Chenab and the Jhelum

Question 55.
What is a canyon?

Answer: It is a deep gorge with steep sides containing many streams, e.g., the Grand Canyon of the Colorado river

Question 56.
Where are most of the fresh water lakes located?
Year of Question :(2012)

Answer: In the Himalayan region

Question 57.
Which is the largest natural freshwater lake of India?
Year of Question :(2012)

Answer: The Wular lake in Jammu and Kashmir

Question 58.
Name a lake which has been formed due to tectonic activities?
Year of Question :(2012)

Answer: The Wular lake

Question 59.
Name two salt water lakes on the eastern coast of India?
Year of Question :(2012)

Answer:

• The Chilika Lake
• The Pulicat Lake

Question 60.
Write two causes responsible for the increase in demand of water?
Year of Question :(2016)

Answer:

• Growing population
• Urbanisation

Question 61.
Write any two uses of the river water?
Year of Question :(2012)

Answer: River water is used for farming, drinking, domestic and industrial uses

Question 62.
Write any two causes of pollution of water of the Ganga river?
Year of Question :(2017)

Answer:

• Disposal of raw sewage and industrial wastes from towns and cities
• Reduction in water flow due to abstraction of water for irrigation from the Ganga through canals

Drainage Class 9 Important Questions Short Answer Type Questions

Question 1.
Describe any three features of Himalayan rivers?
Year of Question :(2012)

Answer: Features of the Himalayan Rivers

• They are perennial in nature
• They have large basins
• They perform intensive erosion activity in their upper course and carry huge load of silt and sand

Question 2.
Define a river system and describe two characteristics of river Indus?
Year of Question :(2013)

Answer: A river along with its tributaries is called a river system. Characteristics of River Indus

• 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 flows through Pakistan and help in agricultural activities
• The main tributaries of Indus are Nubra, Hunza, Sulley, Beas, Ravi, Chenab, Jhelum. (any two)

Question 3.
Write a short note on the Brahmaputra river system?
Year of Question :(2014)

Answer:

• The Brahmaputra originates in Tibet where it is known as Tsangpo
• It flows eastwards parallel to the Himalayas, but it takes a U-tum around the Namcha Barwa and enters India in Arunachal Pradesh
• It is responsible for creating a havoc of floods in Assam and Bangladesh
• This river receives less volume of water and has less silt in Tibetan part, but it carries a large volume of water and silt in India
• It has a braided channel in most of its length in Assam with a few large islands within the channel

Question 4.
Describe any three features of Ganga-Brahmaputra delta?
Year of Question :(2015)

Answer:

• The Sundarban Delta derived its name from the Sundari tree which grows well in marshland
• It is formed by the rivers Ganga and the Brahmaputra
• It is the worlds largest and fastest growing delta
• It is also the home of Royal Bengal Tiger

Question 5.
Why do the Himalayan rivers get flooded every year? What are its advantages?
Year of Question :(2016)

Answer:

• The Himalayan rivers receive water from the melted snow from the lofty mountains as well as from rain
• During monsoons, due to heavy rainfall, these rivers get flooded every year

Advantages:

• The Himalayan rivers flood parts of the northern plains enfiching the soil for the extensive agricultural lands
• Various food crops and cash crops are grown in these fertile lands

Question 6.
What progress has been made in the Ganga Action Plan?
Year of Question :(2017)

Answer:

• Sixty-nine schemes have been completed with positive results
• Trees have been planted in badly eroded portions
• Check dams have been repaired in the upper reaches of the river
• Interception and diversion of several major drains carrying sewage and industrial wastes to the river in some cities like Varanasi, Kanpur, Patna have reduced the pollution level
• Turtles and the Gangetic dolphins which had disappeared for several years have now reappeared in Varanasi and other places

Question 7.
Why are most of the Peninsular rivers draining into the Bay of Bengal? Give reasons. Name the two rivers draining into the Arabian Sea?
Year of Question :(2018)

Answer:

• (a) The main water divide in Peninsular India is formed by the Western Ghats, which runs from north to south close to the western coast
• (b) The Deccan Plateau is higher in the west and slopes gently eastwards
Thus, most of the peninsular rivers such as Mahanadi, the Godavari, the Krishna and the Kaveri flow eastwards and drain into the Bay of Bengal
• (c) The river Narmada and river Tapi drain into the Arabian Sea

Question 8.
Which two rivers of Peninsular India form estuaries? Name the states in which these rivers drain the water?
Year of Question :(2012)

Answer:

• The river Narmada and the Tapi form estuaries
• The Narmada basin covers parts of Madhya Pradesh and Gujarat
• The Tapi basin covers parts of Madhya Pradesh, Gujarat and Maharashtra

Question 9.
Why are Peninsular rivers seasonal in nature? Give any three reasons?
Year of Question :(2012)

Answer:

• The flow of Peninsular rivers is dependent on rainfall
• The Peninsular rivers have shorter and shallower courses as compared to their Himalayan counterparts
• The tributaries are very short and less in number and bring quite less amount of water which hardly increases the amount of water of the main river. Therefore, during the dry season, even the large rivers have reduced flow of water in their channels

Question 10.
Which two peninsular rivers flow westward? Mention one similarity and one difference between these two rivers?
Year of Question :(2012)

Answer: Narmada and Tapi

Similarity:

• These rivers flow through rift valley
• The tributaries of these rivers are small in size

Difference:

• Tapi is the second largest river of Peninsular India and Narmada is the fifth largest river
• Narmada river forms an estuary before entering into the Gulf of Khambhat. On the other hand Tapi does not form an estuary

Question 11.
Describe the main features of Narmada Basin?
Year of Question :(2012)

Answer:

• All the tributaries of the Narmada are very short and most of these join the mainstreams at right angle
• The river forms an estuary before entering into the Gulf of Khambhat
• The river Narmada rises in the Amarkantak hills and flows towards the west in a rift valley formed due to faulting

Question 12.
Describe the main features of Tapi Basin?
Year of Question :(2012)

Answer:

It is the second largest river of the peninsular, 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

Question 13.
Describe any three important features of the Krishna Basin?
Year of Question :(2015)

Answer:

• The river Krishna rises from a spring near Mahabaleshwar. It flows for about 1400 kms
• 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

Question 14.
Why is the Godavari river also known as Dakshin Ganga? HOTS?
Year of Question :(2012)

Answer:

• The Godavari is the largest peninsular river
• Its drainage basin is also the largest among the peninsular rivers. The basin covers parts of 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
• Because of its length and the area it covers, it is also known as the Dakshin Ganga

Question 15.
Describe any three important features of the Mahanadi Basin?
Year of Question :(2018)

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 kms
• Its drainage basin is shared by Maharashtra, Chhattisgarh, Jharkhand and Odisha

Question 16.
Describe any three important features of the Kaveri Basin?
Year of Question :(2012)

Answer:

• 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
• Its main tributaries are Amravati, Bhavani, Hemavati and Kabini
• Its basin drains parts of Karnataka, Kerala and Tamil Nadu

Question 17.
Mention any three similarities between the Himalayan rivers and Peninsular rivers?
Year of Question :(2012)

Answer:

• Both the river systems form delta
• Himalayan and Peninsular rivers both have their large drainage basins
• The rivers of both the regions are joined by several tributaries which increase the volume of water and silt of the main river. For example, Himalayan River: The tributaries of river Ganga are Yamuna, Kosi, Gandak etc. Peninsular River: The tributaries of river Godavari are the Purna, the Wardha, the Pranhita, the Manjra, the Wainganga and the Penganga

Question 18.
Why rivers are regarded as the lifelines of human civilization?
Year of Question :(2012)

Answer: Rivers are regarded as the lifelines of human civilization because

• Most of the civilizations have developed along the river valley. For example, Indus Valley Civilization near river Indus and Mesopotamian Civilization near river Euphrates and river Tigris
• River provides settled life as growth of food and crops is possible and convenient near rivers
• People have always used rivers to travel across places and for the transport of men and material from one place to another

Question 19.
What do you think will happen to the human beings in the absence of scarcity of freshwater? HOTS?
Year of Question :(2014)

Answer: Water is a vital nutrient that constitutes 75% part in our body. It removes waste materials and circulates and replenishes nutrients in our body. Since sea water is salty in nature, it cannot substitute fresh water. Beside this, animals and plants are also dependent on water for their survival

Drainage Class 9 Important Questions Long Answer Type Questions

Question 1.
Describe the four drainage patterns?
Year of Question :(2012)

Answer: The four drainage patterns are as follows

• Dendritic: The dendritic patterns develop where the river channels follows the slope 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 flows in different directions from a central peak or dome-like structure

Question 2.
"Rivers constitute the most useful natural resources." Support the statement with five suitable examples. HOTS?
Year of Question :(2012)

Answer: Rivers are the most important natural resources because

• Rivers provide water for survival and growth of all organisms
• Rivers provided ideal conditions for the early man to lead a settled life
• Rivers have built flood plains, deltas and provide fertile soil for agriculture
• Water from rivers is used for drinking, irrigation and for generating hydro- electricity
• Man is able to supplement his food supply with the fish in the rivers. Rivers also serve as natural waterways
• Worlds earliest civilization developed in the river valleys, e.g., Nile Valley civilization, Indus Valley civilization etc. River Valleys are the worlds best agricultural lands, and are densely populated regions

Question 3.
Explain the main features of the rivers originating from the Himalayas?
Year of Question :(2013)

Answer:

• Most of the Himalayan rivers are perennial. It means that they have water throughout the year
• The Himalayan rivers have long courses from their source to the sea
• These perform intensive erosional activity in their upper courses and carry huge loads of silt and sand
• They have cut through the mountains making gorges
• They also have well-developed deltas

Question 4.
Write the main features of the Ganga system?
Year of Question :(2015)

Answer:

• The Ganga has two headstreams-the Alaknanda and the Bhagirathi. They join together at Devprayag
• From the Himalayas the Ganga enters the plains at Haridwar. It is joined together by a large number of tributaries like Ghaghara, the Gandak and the Kosi
• The Yamuna and the Son are the two main right bank tributaries of the Ganga
•  The Ganga enters Bangladesh as Padma. It flows southward through Bangladesh, and is joined by the Brahmaputra and is known as the Jamuna. After receiving Meghna, it is known as the Meghna
• The length of the Ganga is over 2500 km, and it has the largest basin

Question 5.
Why does Brahmaputra become a big river on entering India?
Year of Question :(2016)

Answer:

• In Tibet, the Brahmaputra river carries a smaller volume of water and less silt as it is a cold and dry area
• It enters India from Arunachal Pradesh and is joined by many tributaries such as the Dibang, the Lohit etc
• It passes through a region of high rainfall. Here, the river carries a large volume of water and considerable amount of silt
• Every year during the rainy season, the river overflows its banks
• Brahmaputra is marked by huge deposits of silt on its bed causing the river bed to rise

Question 6.
Mention the main features of the Ganga Action Plan?
Year of Question :(2012)

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
• 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

Question 7.
Distinguish between a Delta and an Estuary?
Year of Question :(2012)

Answer:

S.No	Delta	Estuary
(i)	The triangular deposits made by the river at its mouth form delta	The sharp edge at the mouth of the river devoid any deposits is known as estu
(ii)	Deltas are formed in the regions of low tide and coastal plains	The regions of high tides and rift valleys witness estuaries
(iii)	Deltas are fertile lands	Estuaries do not have fertile lands
(iv)	The river Ganga, the Krishna, the Godavari, are some of the rivers which form deltas	Narmada and Tapi rivets form estuarie

Question 8.
Distinguish between perennial and non-perennial rivers?
Year of Question :(2012)

Answer:

S.No	Perennial	Non-Perennial
(i)	These rivers have water throughout the year	These have water only during the rainy season
(ii)	Rainfall and melted snow are the source of water for these rivers	Rainfall is the only source of water for these rivets
(iii)	Most of the Himalayan rivers are perennial	Most of the Peninsular rivers are non-perennial

Question 9.
Explain the National River Conservation Plan (NRCP) in brief?
Year of Question :(2010)

Answer: The activities of Ganga Action Plan (GAP) Phase-I, initiated in 1985, were declared closed on 31st March, 2000. The Steering Committee of the National River Conservation Authority reviewed the progress of the GAP and necessary correction on the basis of lessons learnt and experiences gained from GAP Phase-I. These have been applied to the major polluted rivers of the country under the NRCP. The Ganga Action Plan (GAP) Phase-II, has been merged with the NRCP. The expanded NRCP now covers 152 towns located along 27 interstate rivers in 16 states. Under this action plan, pollution abatement works are being taken up in 57 towns. A total of 215 schemes of pollution abatement have been sanctioned. So far, 69 schemes have been completed under this action plan. A million litre of sewage is targeted o be intercepted, diverted and treated

Question 10.
Differentiate between freshwater lakes and saltwater lakes giving examples of each?
Year of Question :(2012)

Answer:

Freshwater Lakes

• Freshwater lakes are mostly found in the Himalayan region
• They are of glacial origin which means that they were formed when glaciers dug out a basin which was later filled with snow melt
• The Wular lake in Jammu and Kashmir is the result of the tectonic activity
• The Dal lake, Bhimtal, Nainital, Loktak and Barapani are some other important freshwater lakes

Saltwater Lakes:

• Spits and bars form lagoons in the coastal areas, e.g., the Chilika lake, the Pulicat lake, the Kolleru lake are the saltwater lakes
• Lakes in the regions of inland drainage are the saltwater lakes, e.g., the Sambhar lake in Rajasthan. Its water is used for producing salt

Question 11.
Why are rivers important for the countrys economy? HOTS?
Year of Question :(2012)

Answer: The rivers are important for a countrys economy for the following reasons

• Rivers are an integral part of our folklore and folk songs. Water from the rivers is a basic natural resource essential for human, agriculture and industrial activities. This activity in its form is uneconomic but in its long term becomes economic one. For example, Sahitya Academy, transmission of dramas, plays and stories to abroad bags hard currency to India
• 80% main stay of population in India on agriculture indicates itself how important the surface water is for Indian economy
• Tourism industry has developed by leaps and bounds in each country of the world after globalisation in twenties. This industry bags millions currency in American dollar (i.e., the hard currency)
• Human nature never does anything without his direct or indirect purpose, objective, mission inherited or hidden therein. Mostly they prefer to earn, to live a peaceful life, to take refuge (nomads, sophisticated) etc. all selfish and not national. However, as seeds are spread on the wings of insects, the literature, culture, activities (positive or negative) sent and transmitted. Gradually, it gives birth to bilateral trade and commodity of countiy is concerned in the countries of the entire world. It is globalisation of economy hence, sprouts in economic activities

Question 12.
What are the major factors responsible for river pollution? Explain?
Year of Question :(2012)

Answer:

• High Demand of Water: 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 river reducing its volume
• Industralisadon: 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. For example, given the adequate streamflow, the Ganga water is able to dilute and assimilate pollution loads within 20 km of large cities. But the increasing urbanisation, and industrialisation do not allow it to happen and the pollution level of many rivers has been rising
• Agricultural Pollution: The extensive uses of chemicals in the form of fertilizers and pesticides in agriculture have left the water bodies contaminated with heavy metals. Such heavy metals enter human body through the food we eat, and many of them cause health problems such as cancer

Question 13.
What are the causes of water pollution? How can it be controlled?
Year of Question :(2012)

Answer:

• The factories discharge their effluents in the nearby rivers, which cause water pollution
• The disposal of sewage of urban centres into the rivers is also responsible for water pollution
• The overuse of fertilisers and pesticides also pollute the water
• Water in the oceans gets polluted by the leakage of oil from oil tankers

Methods to Control Water Pollution:

• The waste product from the factories should not be allowed to fall into the rivers
• The waste materials should be treated before it is allowed to fall into the water of rivers
• Sewage of urban centres should not be allowed into rivers at any cost
• The fertilisers and pesticides should not be overused
• Oil spills from tankers should not be allowed to enter any water body