Class 7 Science - Chapter Water: A Precious Resource NCERT Solutions | Explain the factors responsible for the
Explain the factors responsible for the depletion of water table.
Some of the factors which affect the water table at a place and make it go falling down are as follows:
1. Increasing Population: The increasing population needs water in the higher proportion for its day full activities. As the population is increasing, more houses, shops, offices, schools, industries, roads and pavements, etc. need to be built and for this huge amount of water is required. Usually, groundwater is consumed for constructed work and this decreases the seepage of rain water from the ground. So, due to increasing population, we are consuming more groundwater and on the other hand we are allowing less rainwater to go into the ground. This leads to the depletion of water table.
2. Increasing Industries: Industries produce a large number of numerous things that we use in our everyday life. Almost everything that is made in industries needs water at some stage during the production, due to which water level is decreasing day by day. As the population is increasing, the demand for various industrial goods are increasing and hence the number of industries are also increasing simultaneously. Water used by most of the industries is drawn out from the ground which results in depletion of water table.
3. Scanty Rainfall: ‘Insufficient rainfall’ is called ‘scanty rainfall’ that means is not enough. Sometimes scanty rainfall occurs during the rainy season. Since there is less rainfall, less rainfall goes into the ground. In such a situation, much more groundwater is drawn out by the people for various purpose than gets replenished by rainfall. This leads to depletion in water table or level.
4. Deforestation: The cutting down of trees and plants from the forest for various purposes (like for the industrial area) is called deforestation. We know that forest help in bringing rain by making the air cooler and with the higher transpiration rate. So lower number of trees and plants in the forests will bring less rainfall. So, deforestation leads to lesser rainfall as well as lesser seepage of rainfall into the ground.
5. Decreases in Effective Area for Seepage of Rainfall: Due to increasing population, urbanisation and industrialisation, more and more space is being covered by houses, other buildings, roads etc. The open spaces having unpaved ground are getting reduced on the daily basis. It is the ‘unpaved ground’ which lets the rainwater seeps into the ground and recharges the groundwater table. Since, the effective area for seepage of rainwater in urban areas is decreasing day by day, less and then less rainwater seeps into the ground which leads to the depletion of water table.
More Questions From Class 7 Science - Chapter Water: A Precious Resource
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Make a sketch showing groundwater and water table. Label it.
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Explain how groundwater is recharged?
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There are ten tubewells in a lane of fifty houses. What could be the long term impact on the water table?
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Mark ‘T’ if the statement is true and ‘F’ if it is false:
(a) The freshwater stored in the ground is much more than that present in the rivers and lakes of the world. (T/F)
(b) Water shortage is a problem faced only by people living in rural areas. (T/F)
(c) Water from rivers is the only source for irrigation in the fields. (T/F)
(d) Rain is the ultimate source of water. (T/F) - Q:-
Fill in the blanks with the appropriate answers:
(a) People obtain groundwater through________ and ________. (b) Three forms of water are ________, ________ and ________.
(c) The water bearing layer of the earth is ________.
(d) The process of water seepage into the ground is called ________. - Q:-
Choose the correct option. The total water
(i) in the lakes and rivers of the world remains constant.
(ii) under the ground remains constant.
(iii) in the seas and oceans of the world remains constant.
(iv) of the world remains constant. - Q:-
Which one of the following is not responsbile for water shortage?
(i) Rapid growth of industries
(ii) Increasing population
(iii) Heavy rainfall
(iv) Mismanagement of water resources
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