All living beings require water for their existence and survival. Infact without water there would be no life on the earth.
The utility of Water is Immense
- It is required for domestic purposes like cooking, drinking and washing etc.
- It is used for agriculture, pastoral industry and manufacturing industries.
- Water is also used to harness hydro-electric power.
About three-fourth of the earth’s surface is covered with water, that means there is no shortage of water. In spite of all this most of the countries of the world are facing water crisis. This is because only a small proportion of water accounts for fresh water that can be put to use.
The fresh water is mainly obtained from surface run off and ground water.
The four main stages of water cycle are
- Evaporation 2. Transpiration 3. Condensation 4. Precipitation
Water : Some Fact and Figures
(According to the UN World Water Development Report, 2003)
- 96.5 % of the total volume of world’s water is estimated to exist as oceans and only 2.5 % as fresh water. Nearly 70 % of this fresh water occurs as ice sheets and glaciers in Antarctica, Greenland and the mountaineous region of the world while a little less than 30 % is stored as ground water is the world’s aquifers.
- India receives nearly 4 % of the global precipitation and ranks 133 in the world in terms of water availability per person per annum.
- The total renewable water resources of India are estimated at 1, 897 km2 per annum.
- By 2025, it is predicted that large parts of India will join countries or regions having absolute water scarcity.
Water scarcity : Shortage of water as compared to its demand is known as water scarcity.
Factors responsible for water scarcity.
It is one of the basic factors which is responsible for water scarcity. Most of our cities are facing this problem due to over population. A large population means more water not only for domestic use but also to produce more food.
Commercialization of Agriculture
The commercial crops need more water and other inputs. Assured means of irrigation like tubewells and wells are responsible for falling ground water levels.
Variation in seasonal and annual precipitation
Precipitation is the main source of water in India but arrival and departure of monsoon in India is uncertain. Even the distribution of rain fall is uneven.
Industrialization and Urbanization
The ever increasing number of industries has made matters worse by exerting pressure on existing fresh water resources. Industries apart from being heavy user of water also requires power to run them.
Most of our cities are over populated. Over population over utilizes the water resources and also pollutes the existing resources.
Due to over utilization the water table has lowered.
Domestic waste and industrial waste are the main factors responsible for pollution of water.
Need of the hour to conserve and manage the water resources.
- To safe guard ourselves from health hazards.
- To ensure food security.
- Continuation of our livelihoods and productive activities.
- Prevent degradation of our natural ecosystem.
Multi-Purpose River Projects and Integrated Water-Resource Management
Multi purpose Project : A multipurpose project is that which fulfils a variety of purposes at the same time. Example : irrigation, generation of electricity etc.
Main objectives or Advantages of Multipurpose Project
- Generation of Power : They produce neat, pollution free and cheapest energy which is the back bone of industry and agriculture. According to the economic survey 2005-06 these produce more than 30, 000 M.W. power.
- Flood Control : These projects control the flood because water can be stored in them. These projects have converted many ‘rivers of sorrow’ into river of boon. Example River Kosi.
- Soil Conservation : These conserve the soil because they slow down the speed of water.
- Irrigation : They irrigate the fields during the dry seasons. Many canals have been dug and they irrigate dry areas.
- Afforestation : Trees are systematically planted in and around reservoirs. This helps in preserving “Wild life” and natural ecosystem.
- Water Navigation : They provide for Inland water navigation through main river or canal. It is the cheapest means of transport for heavy goods.
- Fisheries : These provide ideal condition for the breeding of fish. Choosen varieties of fish are allowed to grow.
- Tourist Centres : These projects are well cared and are scientifically developed. So these become the centre of tourist attraction.
Disadvantage of Multipurpose Project
- High Cost : The initial cost of building the dams is very high. It requires a lot of capital and engineering skills and modern machinery which is not available in India.
- Adverse Impact on Environment : A vast variety of flora and fauna as well as human settlements get submerged in the water of reservoir formed by the dam.
- Adverse effect on the fertility of the soil : Due to construction of dams there are no annual floods in the river. And because of this the soil of the down stream region does not get nutrient rich “silt”. This decreases the fertility of the soil.
- Adverse Impact on aquatic life : Due to construction of dam on the river, the fish in the down stream area do not get sufficient nutrient material.
- Non-availability of water throughout the year : Most of the rivers in India flow only for few months. So water is not sufficient to build a dam.
- Disputes between different states : States have disputes over sharing of water, height of the dam and so on.
- Displacement of local communities : The local people often have to give up their land and livelihood and their meagre access and control over resources for the greater food for the Nation.
- Change in cropping pattern : They provide assured means of irrigation to farmers. Due to this most of the farmers have changed the cropping pattern shifting to water intensive and commercial crops. This has led to salinisation of soil leading to ecological imbalance.
- (i) Regulating and damming of rivers affect their natural flow causing poor sediment flow and excessive sedimentation at the bottom of the reservoir, resulting in rockier stream beds and poorer habitats for the rivers aquatic life.
(ii) Dams also fragment rivers making it difficult for aquatic fauna to migrate, especially for spawning. The reservoirs that are created on the floodplains also submerge the existing vegetation and soil leading to its decomposition over a period of time.
Rain Water Harvesting
Rainwater Harvesting : It is a technique of increasing the recharge of ground water by capturing and storing rain water by constructing structures such as percolating pits, check dams etc.
Different Techniques to Conserve Water
- People of mountaneous regions had built diversion channels like ‘guls’ and ‘kuls’ for agriculture.
- Rooftop rain water havesting was commonly practiced to store drinking water. eg. Rajasthan.
- In the flood plain of Bengal, people developed inundation channels to irrigate their fields.
- In arid and semi-arid regions, agriculatural fields were converted into rain fed storage structure that allowed the water to stand and moisten the soil like the ‘Khadins’ in Jaisalmer and ‘Johads’ in other parts of Rajasthan.
Rain Water Harvesting through Tanks
- In the semi arid and arid region of Rajasthan particularly in Phalodi, Bikaner and Barmer most of the houses, have underground tanks for storing water.
- These tanks were part of well developed roof top rain water harvesting system.
- Rain falling on the rooftops would travel down the pipe and was stored in tankers.
- The first spell of rain was usually not collected as this would clean the roofs and the pipes.
- The rain water from the subsequent showers was then collected.
Importance of Rain Water Harvesting
- It is a reliable source of water when all other source of water dry up.
- It is considered the pure form of natural water.
- It can also be given to sick people.
- It can be used to beat the summer heat if underground rooms adjoining the tanks are built.
- To meet the increasing demand of water.
- To avoid flooding of roads.
- To raise the ground water level.
Conservation of Water Resources
- Construction of multi-purpose projects and canals.
- Solving river water disputes quickly.
- Inter basin transfer of water.
- Measures to raise underground water.
- Rainwater harvesting and water shed development.
- Avoiding pollution of water bodies.
- Preventing the wastage of water.
- Biosphere : Part of the earth which is covered by living organisms both plants and animals.
- Dam : A barrier across the flowing water.
- Flora : Plants of particular region or period are referred to as flora.
- Fauna : Species of animals are known as fauna.
- Forest : Extensive area covered with trees.
- Ground water : Water which is obtained from a depth of more than 15 m.
- Hydroelectricity : It is the power which is generated with the help of running water.
- Multipurpose Project : A river valley project which serves a number of purposes.
- Perennial Canals : Canals developed by a diverting water from rivers that flow throughout the year.
- Soil : The upper layer of the ground containing weathered rocks and humus.
- Water Scarcity : Shortage of water as compared to its demand.
- Rain water harvesting : It is a technique of increasing the recharge of ground water by capturing and storing rainwater by constructing structures such as percolating pits, check dams etc.
- Drip Irrigation : A type of irrigation where water gets dropped in the form of drops near the roots of the plant mainly to conserve the moisture.
- Inundation canal : Canal meant for diverting flood waters mainly during the rainy season.
- Irrigation : Artificial means of supplying water to farm lands in the form of canals, wells, tubewells and tanks.
- Surface water : Water flowing on the earth’s surface in the form of rivers, lakes etc.
- Tank : Natural or man made reservoir to store rain water.
Some Facts About Water
- Total volume of water in ocean (world) – 96.5 %.
- Fresh water –2.5 %.
- Ice sheets and glaciers – 70 %.
- Stored as ground water in world’s aquifers – 30 %.
- India’s share in global precipitations – 4 %.
- Average flow of water in river system in India –1869 m3.
Major-Multipurpose Project of India
|1||Bhakra Nangal||Satluj||Punjab, Haryana, Rajasthan||14.6||1204|
|2||Damodar Valley||Damodar||Jharkhand, West Bengal||4.5||260|
|4||Chambal Valley||Chambal||Rajasthan, M.P.||4.22||386|
|7||Tungabhadra||Tungabhadra||Andra Pradesh, Karnataka||2.5||99|
|9||Nagarjuna Sagar||Krishna||Andhra Pradesh||8.62||450|
|10||Narmada Valley||Narmada||M.P., Gujarat||—||—|
|11||Indira Gandhi Cananl||Beas, Satluj||Punjab, Haryana, Rajasthan||11.63||—|
Very Short Answer Type Question
- How is fresh water obtained ?
- What are the sources of fresh water ?
- Mention any two regions which are expected to face water shortage.
- How do people conserve water in hills ?
- What is a multipurpose project ?
- What is a dam ?
- Why is the need for water increasing day by day ?
- Mention any two measures for conservation of water resources ?
- State the factors responsible for bad quality of water ?
- What is water scarcity ?
- Mention some common methods to increase Water Resources.
- Which is the primary source of water on the earth ?
- Explain the water as a renewable resource.
- Why is irrigation necessary in India ?
- Name any two social movements which have been launched against the multi-purpose projects.
- How do people harvest water in the flood plains of Bengal ?
- How do people harvest water in the semi-arid and arid regions of Rajasthan.
- Many people of arid and semi-arid regions construct underground rooms adjoining the water tanks. Give reason.
- Name any two states where rooftop water harvesting is most common.
- Name two techniques of rooftop rain water harvesting.
- What is the need of rain water harvesting ?
- Name the dam constructed on Narmada river
- Name the river on which Nagarjuna Sagar dam is constructed.
- Name the river on which the Mettur dam has been built.
Short Answer Type Question
- What is water scarcity ? Mention any four factors of water scarcity ?
- “Need of the hour is to conserve and manage our water resources”. Mention any four reasons.
- How do dams create conflicts between the people ?
- How has irrigation changed the cropping pattern ? What is its impact on the social land scape ?
- Why is the scarcity of water increasing day by day in our country ? Give any four reasons.
- What is the need for conservation of water resources ?
- Distinguish between surface water and ground water ?
- Discuss the main objectives of rain water harvesting.
- How can we recharge ground water ?
- How can floods be controlled ?
- What is a multi-purpose project ?
- Define the term, Tankas.
- What is Kul ?
- Name any two regions of India which suffer from water scarcity.
Long Answer Type Question
- Write a brief note regarding irrigation in India, mentioning their types and problems.
- Multipurpose projects are called the “Temple of modern India”. Discuss.
- What are the drawbacks of multipurpose river project ?
- Discuss the methods of conservation of water.
- “Water is a very important and critical resource in India”. Support this statement by explaining any five points of each.
- How have the growing population, industrialisation and urbanisation led to water scarcity ? Explain.
- Why is there a need to conserve water resources?
- Distinguish between a dam and a multipurpose project.
- How do the multipurpose river projects affect the aquatic life ? Explain.
- Explain the quantitative and qualitative aspects of water scarcity.
Multiple Choice Question
1. The first multipurpose project of India was –
(A) Sivasamudram (B) Damodar Valley
(C) Hira Kund (D) Rajasthan Canal
2. Sardar Sarovar Dam is constructed on –
(A) River Krishna (B) River Mahanadi
(C) River Kaveri (D) River Narmada
3. Rooftop rainwater harvesting system in Rajasthan is known as –
(A) Guls (B) Tankas
(C) Johads (D) Boolis
4. Bamboo drip irrigation is common in the state is –
(A) Rajasthan (B) Madhya Pradesh
(C) Meghalaya (D) Goa
5. How can fresh water be renewed ?
(A) By ground water
(B) By hydrological cycle
(C) By dam
(D) By canal
6. A fine soil which is formed in flood plains is known as –
(A) Kankar (B) Sediment
(C) Silt (D) None of these
7. People harvest water in the flood plain of Bengal by –
(A) Inundation channels
8. Precipitation, surface run off and ground water are the source of –
(A) Polluted water
(B) Under ground water
(C) Waste water
(D) Fresh water
9. “Khadins” are mostly found in –
(A) Kota (B) Jaisalmer
(C) Barmer (D) Bikaner
10. Total volume of fresh water is available on the earth is –
(A) 2.5 % (B) 3.25 %
(C) 3 % (D) 4 %
11. The total renewable water resources of India are –
(A) 1.88g km3 (B) 1.890 km3
(C) 1.798 km3 (D) 1.897 km3
12. India ranks …….. in the world in terms of water availability per person per annum –
(A) 123 (B) 145
(C) 133 (D) 140
13. India receives global precipitation about –
(A) 4 % per annum (B) 6 % per annum
(C) 5 % per annum (D) 2 % per annum
14. The total irrigated area covers …………. of the total cultivated area –
(A) 1/4 (B) 1/3
(C) 1/2 (D) 1/5
15. The area irrigated by tanks is –
(A) 6 % (B) 7 %
(C) 8 % (D) 9 %
16. The area irrigated by canal is –
(A) 42 % (B) 45 %
(C) 43 % (D) 40 %
17. The area irrigated by wells –
(A) 25 % (B) 21 %
(C) 22 % (D) 23 %
18. …………… receives the highest rainfall in the world
(A) Mawsynram (B) Cherapunji
(C) Shimla (D) None of these
19. The total river water flow utilised or stored is –
(A) 8.2 % (B) 8 %
(C) 9.25 % (D) 8.5 %
20. The annual flow of the Indian river water is estimated about ……………….. cubic metres –
(A) 690 (B) 790
(C) 890 (D) 590
21. ………is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment.
(A) Multipurpose project
22. The Tehri Dam is being constructed on the river
(A) Ganga (B) Yamuna
(C) Bhagirathi (D) Satluj
23. Hirakud dam is on river……
(A) Satluj (B) Mahanadi
(C) Narmada (D) Krishna
24. Which of the following is not correctly matched?
(A) Salal-Chenab (B) Bhakra-Satluj
(C) Mettur-Mahanadi (D) Koyna-Krishna
25 ……are the underground tanks for storing drinking water.
(A) Kul (B) Canal
(C) Tankas (D) PVC pipes