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

NCERT Solutions Class 7 Science Chapter 16 Water: A Precious Resource is provided here to help students in understanding the topic thoroughly. All these solutions are solved by experts with a detailed explanation. Class 7 NCERT Solutions for Science Chapter 16 includes all the textbook exercise questions and answers. These solutions will help students complete their assignments & homework.

## NCERT Solutions for Class 7 Science Chapter 16 Questions and Answers

Exercise Questions

Question 1: Mark âTâ if the statement is true and âFâ 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)

(a) True
(b) False
(c) False
(d) True

Question 2: Explain how groundwater is recharged?

Answer: The rainwater and water from other sources such as rivers and ponds seeps through the soil and fills the empty spaces and cracks deep below the ground. The process of seeping of water into the ground is called infiltration. By the process of infiltration, groundwater gets recharged.

Question 3: There are ten tubewells in a lane of fifty houses. What could be the long term impact on the water table?

Answer: Ten tube-wells are too much for a lane of fifty houses, this can lead people to mindlessly exploit the groundwater. This can lead to depletion of the water table in the long run.

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

Answer: To maintain a garden, water is necessary. Therefore, to minimise the use of water, we can apply the drip irrigation method. In this method, water is supplied directly to the base of the plants using narrow pipes, thereby reducing the loss of water.

Question 5: Explain the factors responsible for the depletion of water table.

Answer: Following factors are responsible for depletion of water table:

(i) Increasing population: As a result of increasing population, all the facilities such as houses, shops, roads, offices, pavements, etc. increase to fulfil the increasing demands. This, in turn, decreases the open area for seepage of water into the ground.

(ii) Increasing industries: Most of the stages of manufacturing processes in industries require water. If the number of industries increases, then the water required by them will also increase. Therefore, increase of industries contributes to the depletion of water table.

(iii) Agricultural activities: India is an agricultural country and agriculture is impossible without water. The water for agriculture is mainly utilised from ground water, rain water and canal water. As there is no rainfall in many places, agriculture cannot be entirely depended on rain water. Also, canal water is available in a few places only. Therefore, ground water is the main source of water for agricultural activities and this causes depletion of water table.

(iv) Lack of water conservation techniques: Main source of water on earth and for the underground water is rain. The water of the rain, if conserved can increase the ground water level. But this is not done due to lack of water conservative techniques.

Question 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 ________.

(b) liquid, gas
(c) aquifer
(d) infiltration

Question 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

Question 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.

Answer: (iv) of the world remains constant.

Question 9: Make a sketch showing groundwater and water table. Label it.