# NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

Written by Team Trustudies
Updated at 2021-05-07

## NCERT solutions for class 7 Science Chapter 16 Water A Precious Resource Exercise

Q.1 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)

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

(a) The freshwater stored in the ground is much more than that present in the rivers and lakes of the world. (T)

(b) Water shortage is a problem faced only by people living in rural areas. (F)

(c) Water from rivers is the only source for irrigation in the fields. (F)

(d) Rain is the ultimate source of water. (T)

Q.2 Explain how groundwater is recharged.

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

(1) The rainwater and water from other sources such as rivers and ponds seep through the soil and fills the empty spaces and cracks deep below the ground.

(2) The process of seeping water into the ground is called infiltration.

(3) The groundwater thus gets recharged by this process.

Q.3 There are ten tube wells in a lane of fifty houses. What could be the long term impact on the water table?

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

(1) If the people of the fifty houses use the ten tube wells, then the water required by them is drawn from the ground.

(2) If these tube wells are used for a long time, then the groundwater would be reduced and the water table would go down.

(3) This results in depletion of groundwater level.

Q.4 You have been asked to maintain a garden. How will you minimise the use of water?

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

To maintain a garden, water is necessary.

Therefore, to minimize the use of water :

(1) The drip irrigation method can be used.

In this method, water is supplied directly to the base of the plants using narrow pipes, thereby reducing the loss of water.

(2) Rainwater harvesting can be done and that can be used for the gardening process.

(3) The sprinkler method of irrigation can be used.

Q.5 Explain the factors responsible for the depletion of water table.

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

The factors responsible for the depletion of the water table are as follows:

(i) Increasing population :

The higher the number of individuals, the higher the need for daily use, which will lead to a decrease in groundwater.

(ii) Increasing industries :

Industries need a lot of water for manufacturing purposes. This reduces the water table.

(iii) Agricultural activities

In a way, an increasing number of agricultural fields will help the population but more the fields will lead to more irrigation systems.

Q.6 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 ___________.

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

(a) People obtain groundwater through tube wells and hand pumps.

(b) Three forms of water are ice , water and vapour.

(c) The water bearing layer of the earth is aquifer.

(d) The process of water seepage into the ground is called infiltration.

Q.7 Which one of the following is not responsible for water shortage?
(i) Rapid growth of industries
(ii) Increasing population
(iii) Heavy rainfall
(iv) Mismanagement of water resources

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

(iii) Heavy rainfall

Q.8 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.

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource

(iv) of the world remains constant.

Q.9 Make a sketch shoyving groundwater and water table. Label it.

NCERT Solutions for Class 7 Science Chapter 16 Water A Precious Resource