WATER RESOURSE CLASS 10

Q1 How is fresh water obtained?

Ans Fresh water is mainly obtained from surface runoff and ground water.

Q2 Howthe fresh water becomes a renewable resource?

Ans Water is continually being renewed and recharged through the hydrological cycle .

Q3 Why is the availability of water resources varies and time due to the variation in seasonal and annual precepitation over space and time?

Ans The availability of water resources varies over space

Q4 Why does an area suffer from water scarcity although water is available in ample amount to meets the needs of people?

Ans Even if there is ample amount of water to meet the needs of the people much of it may be polluted by domestic and industrial wastes chemicals , and, pesticides fertilizers used in agriculture, thus making it hazardous for human use.

Q5 What has happened to India’s rivers especially the smaller ones?

Ans India’s rivers especially the smaller ones are turning into toxic streams due to population growth, agricultural modernization, urbanization and industrialization.

Q6 Why should we conserve water resource?

Ans We need to conserve water resource

• To safeguard ourselves from health hazards

• To ensure food security

• To continue our livelihoods

• For productive activities

• To prevent degradation of our natural ecosystems

Q7When was Bhopal lake built?

Ans Bhopal lake was built in 11th century.

Q8What is a dam?

Ans A dam is a barrier across flowing water that obstructs, directs or retards the flow,often creating a reservoir ,lake or impoundment. Dam refers to a reservoir rather than structure.

Q9 Attempt the classification of dams on the basis of material used

and height.

Ans Dams are classified according to material used and intended purpose or height

—A)On the basis of structure and the material used dams are classified

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(a)Timber dams (b)Embankment dams (c) Masonary dams

There are many subtypes of t

hese dams

B) On the basis of height

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(a)Low dams (b) Medium dams (c) High dams

Q10 Who proclaimed the dams as the ‘temples of modern India and why?

Ans Jawahar Lal Nehru proudly proclaimed the dams as ‘temples of modern India’, the main reason being that it would integrate development of agriculture and the village economy with rapid industrialization and growth of the urban economy.

Q11 Differentiate between traditional dams and multi purpose river valley dams.

Ans Traditional dams were built to impound rivers and rainwater that could be used later to irrigate agricultural fields.

Today, dams are built not just for irrigation but for electricity generation, water supply for domestic and industrial uses ,flood control ,recreation ,in

land navigation ,and fish breeding. For example, Bhakhra Nangal project water is used for hydel power production as well as for irrigation.

Q12 What is water scarcity?

Ans According to Falken Mark, a Swedish expert, water stress occurs when water availability is less than 1000 cubic meter per person per day.

Q13Explain the various causes of water scarcity?

OR

What is the quantitative aspect of water scarcity?

Ans(a)Water scarcity may be the outcome of large and growing population and consequent greater demands for water and unequal access to it.

( A) large population means more water not only for domestic use but also to

produce more food .Hence ,to facilitate higher foodgrain production ,water

resources are being over exploited to expand irrigated areas and dry season

agriculture.

Most farmers have their own wells and tubewells in their farms for irrigation to increase their produce. But it may lead to falling of ground water levels adversely affecting water availability and food security of the people.

Post Independence Period

(b)Intensive industrialization is exerting pressure on existing fresh water

resources. Industries, apart from being heavy users of water, also require power to run them. Much of this energy comes from hydro electric power. Today, hydro electricity contributes approximately 22 % of the total electricity produced.

(c)Multiplying urban centers with large and dense populations and urban

-life styles have not only added to water and energy requirements b

ut have further aggravated the problem. Most of these have their own ground water pumping devices to meet their water needs. .Water resources are being over exploited and have caused their depletion in several of these cities. 

Q14Discuss the problems associated with multipurpose river valley projects.

Ans The problems associated with multipurpose projects and large dams are following

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AFFECT ON NATURAL FLOW OF RIVER

regulating and damming of rivers affect their natural flow causing poor sediment flow

And excessive sedimentations at the bottom of the reservoir, resulting in rockier stream

beds and poorer habitats for the river’s acquatic life. Dams also fragment rivers making it

difficult for aquatic fauna to migrate, especially for spawning.

SUBMERGENCE OF VEGETATION

The reservoirs that are created on the flood plains also submerge the existing vegetation

and soil leading to its decomposition over a period of time.

SOCIAL PROBLEMS

Multipurpose projects and large dams have also been the cause of many new

social movements like the ‘Narmada Bachao Andolan ’and the’ Tehri Dam Andolan’

.Resistance to these projects have primarily been due to the large scale displacement of

local communities Local people often have to give their land, livelihood and their meagr

e access to and control over resources for the greater good of nation.

CHANGE IN CROPPING PATTERN

Irrigation has also changed the cropping pattern of many regions with farmers shifting to

water intensive and commercial crops. This has great ecological  consequences like

salinisation of the soil. At the same time it has changed the social landscape,i.e.increasing

the social gap between the richer land oweners and the landless poor.

CONFLICTS AND DISPUTES

Dams did create conflicts between people wanting different uses from the same water

resources. In Gujarat, the Sabarmati basin farmers were agitated and almost caused a

riot over the higher priority given to water supply in urban areas ,particularly during

droughts. Interstate water disputes are also becoming common with regard to sharing the

costs and benefits of the multipurpose projects e.g.objections raised by Karnataka and

Andhra Pradesh government regarding the Krishna Godavari water.

TRIGGERS FLOODS

Ironically the dams that were constructed to control floods have rather triggered

floods,due to sedimentation in the reservoir .Moreover ,the big dams have mostly been

unsuccessful in controlling floods at the time of excessive rainfall.In 2006 release of

water from dams during heavy rainfall aggravated the flood situation in Maharashtra and

Gujarat.The floods have also caused extensive soil erosion.

LAND DEGRADATION

Regulating and damming of rivers cause poor sediment flow and sedimentation at the

bottom of the reservoir, which means that the flood plains were deprived of silt ,a

natural fertilizer,further adding on to the problem of land degradation.

OTHER PROBLEMS

It was also observed that the multipurpose projects induced earthquakes, caused water

borne diseases and pests and pollution resulting from excessive use of water.

Q15 What was considered as viable alternative to the multipurpose projects and why?

Ans Water harvesting system was considered as a viable alternative to the multipurpose projects because of

–



The disadvantages and rising resistance

against the multipurpose projects