Water Resources - I Flashcards
(20 cards)
Explain how water becomes a renewable resource.
The freshwater is mainly obtained from surface run off and ground water that is continually being renewed and recharged through the hydrological cycle. All water lives within the hydrological cycle ensuring that water is a renewable resource.
What is the hydrological cycle?
It begins with the EVAPORATION of water from the surface of the ocean. As moist air is lifted, it cools and water vapour CONDENSES to form clouds. Moisture is transported around the globe until it returns as PRECIPITATION.
How much water is not available for consumption?
Only 2.5% of the totals volume of earth’s water is freshwater. 70% of this is glaciers and ice sheets. Less than 30% is stored as groundwater in the world’s aquifers.
How much of the global precipitation does India receive?
4%; ranks 133 in the world in terms of water availability per person per annum.
How much is the total renewable water resource in India?
1,897 km².
What is predicted by 2025?
Large parts of India will join countries or regions having absolute water scarcity.
What is water scarcity?
It is the condition when the fresh water for consumption falls short of the requirement.
What are causes of water scarcity?
⋆ Over-exploitation, excessive use, unequal access to water among different social groups.
⋆ Large and growing population’s increasing demand.
⋆ Facilitation of higher food-grain production by over-exploiting water resources and dry-season agriculture.
⋆ Farmers’ wells and tube-wells lead to falling ground levels.
⋆ Increasing number of industries’ pressure on resources.
⋆Pollution of the available water resources.
What are theme those of water conservation since ancient times?
Constructing sophisticated hydraulic structures like dams built of stone rubble, reservoirs or lakes, embankments and canals for irrigation.
Sringaverapura
Near Allahabad; had sophisticated water harvesting system channeling the flood-water of the river Ganga.
Chandragupta Maurya’s period
Dams, lakes and irrigation systems were extensively built.
Where were evidences of sophisticated irrigation works found?
Kalinga, Nagarjunakonda, Bennur, Kohlapur.
Which is a large artificial lake?
Bhopal Lake, built in the 11th century.
What was constructed by Iltutmish?
The tank in Hauz Khas in Delhi in the 14th century to supplying water to Siri Fort area.
What are the advantages of dams?
⋆ Water supply for domestic and industrial uses
⋆ Electricity generation
⋆ Flood control
⋆ Recreation
⋆ Inland navigation
⋆ Fish breeding
Why are dams called multi-purpose projects?
Because the many uses of the impeded water are integrated with one another. For example, in the Sutluj-Beas river basin, the Bhakra-Nangal river project is being used for both hydro power production and irrigation. Similarly, the Hirakud project in the Mahanadi basin integrated conservation of water with flood control.
What is a dam?
It is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impudent. Dam refers to the reservoir rather than the structure.
What is a weir?
It is a section in most dams also called a spillway over which water will flow either intermittently or continuously.
How can dams be classified?
⋆ Structure (Timber, embankment, masonry)
⋆ Height (large and major, low dams, medium height, and high)
⋆ Intended purpose.
Why were dams thought to be extremely developmental?
It would integrate development of agriculture and the village economy with rapid industrialisation and growth of the urban economy.
