Gujarat Board GSEB Textbook Solutions Class 7 Science Chapter 16 Water: A Precious Resource Textbook Questions and Answers, Notes Pdf.
Gujarat Board Textbook Solutions Class 7 Science Chapter 16 Water: A Precious Resource
Gujarat Board Class 7 Science Water: A Precious Resource Textbook Questions and Answers
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)
Explain how groundwater is recharged.
The groundwater gets recharged through the process of infiltration. Infiltration means seeping of water from rivers and lakes into the empty spaces and cracks deep below the ground.
There are ten tubewells in a lane of fifty houses. What could be the long-term impact on the water table?
The effect on the water table depends on the replenishment of underground water. Only five families will share a tubewell, the water used for daily domestic purposes will not affect the water table. But if there is a shortage of rains, the water used by the family will not be replenished and the water table ‘ will fall down.
You have been asked to maintain a garden. How will you minimize the use of water?
To minimize the wastage of water we will use drip irrigation which throws the water at the base of plants. We will check the leakages in the water pipes and arrange small pits for rainwater harvesting. The collected rainwater will be used later.
Explain the factors responsible for the depletion of the water table.
Various factors responsible for the depletion of the water table are:
1. Increasing population: As the population is increasing day-by-day, so the demand for construction of houses, shops, offices, roads, etc. is also increasing. This decreases the open areas like parks and playgrounds, etc. and thus decreases the seepage of rainwater into the ground.
2. Increasing industries: All industries need water. As the number of human population increase, the number of industries is also increased which definitely increases the consumption of water.
3. Lack of water conservation techniques: The main source of water on earth and for the underground water is rain. The water of the rain, if conserved can increase the groundwater level. But this is not done due to lack of water conservative techniques.
4. Agricultural activities: India is a country which depends on agriculture. The land used for cultivation has increased. So, the consumption of water for agriculture has increased. Irregular rainfall has increased the consumption of groundwater. This has increased the depletion of groundwater.
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 ……….
(a) wells, hand pumps
(b) solid, liquid, gas
Which one of the following is not responsible for water shortage?
(i) The rapid growth of industries
(ii) Increasing population
(iii) Heavy rainfall
(iv) Mismanagement of water resources
(iii) Heavy rainfall
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.
(iv) of the world remains constant.
Make a sketch showing groundwater and water table. Label it.
Extended Learning Activities And Projects
You area water detective in your school You have a team of six members. Survey the campus and make a note of the following:
(a) Total number of taps
(b) Number of taps leaking
(c) Amount of water wasted due to leakage
(d) Reasons of leakage
(e) Corrective measures are taken
Students survey the campus and give answers of the questions on the basis of their observations.
Groundwater pumped out Try to find out if there are any hand pumps in your neighborhood. Go to the owner or the users of a few of these and find out the depth at which they struck water? If there are any differences, think of the probable reason. Write a brief report and discuss it in your class. If possible, visit a place where boring is going on to install a hand pump. Watch the process carefully and find out the depth of the water table at that place.
The depth of the water depends on the water table at that place. Due to the different depth of water tables at different places the hand pumps are bored at different depths.
Catching rainwater – Traditional methods
Form groups of 4 to 5 students in the class and prepare a report on the various traditional ways of water harvesting. If possible, use the following web link: www.rainwaterharvesting. org.
There are various ways of water harvesting like Paris, ponds, and check dams.
Conservation of water
Carry out a campaign to conserve water at home and in the school. Design posters to remind others of the importance of water resources.
Educate the fellow students to:
- Close up the taps after use.
- Take an adequate amount of potable water that is required to drink. Do not take an excess of drinking water which you later on throw.
- Design posters such as people are standing in a queue to collect drinking water from a tap or a water pump.
Create a logo Hold a competition to create a logo or a symbol depicting water scarcity.
Do it yourself.