The DAV Class 4 Science Book Solutions and DAV Class 4 Science Chapter 8 Question Answer – Water Scarcity and Conservation of Water are essential study tools for DAV public school students in Class 4.
DAV Class 4 Science Chapter 8 Question Answer – Water Scarcity and Conservation of Water
DAV Class 4 Science Ch 8 Question Answer – Water Scarcity and Conservation of Water
Something To Know
A. Fill in the blanks.
Question 1.
The earth is known as a ______ planet.
Answer:
Blue
Question 2.
______ and ______ are two major natural sources of water.
Answer:
Rain, snow
Question 3.
Setting up of factories cause a ______ in the level of underground water.
Answer:
Depletion
Question 4.
Cutting of trees in the forests causes a ______ in rainfall.
Answer:
Reduction
Question 5.
Use of water sprinkler for irrigation reduces the ______ of water.
Answer:
wastage.
B. Match the following:
| Column I | Column II |
| (1) cutting of trees in the forests | (a) water conservation |
| (2) collecting rain water for day-to-day use | (b) dam |
| (3) proper utilization of water and avoiding its wastage | (c) deforestation |
| (4) a method of preserving large quantity of water and checking floods | (d) rain water harvesting |
Answer:
| Column I | Column II | |
| (1) cutting of trees in the forests | c | (a) water conservation |
| (2) collecting rain water for day-to-day use | d | (b) dam |
| (3) proper utilization of water and avoiding its wastage | a | (c) deforestation |
| (4) a method of preserving large quantity of water and checking floods | b | (d) rain water harvesting |
C. Tick (✓) the correct option.
1. Two maj or natural sources of water are
(a) rain and wells
(b) snow and rivers
(c) rain and snow
(d) ground water and rivers
Answer:
(c) rain and snow
2. Planting of more trees will help in
(a) reducing the ground water level
(b) setting-up more factories
(c) deforestation
(d) increasing the rainfall
Answer:
(d) increasing the rainfall
3. We can avoid wastage of water by
(a) using water sprinkler for irrigation
(b) over irrigation of fields
(c) washing our car with a jet of water
(d) allowing water to leak from taps
Answer:
(a) using water sprinkler for irrigation
D. Answer the following Questions in brief.
Question 1.
How’ much of the surface of earth is covered by water?
Answer:
Three fourth of the surface of earth is covered by water.
Question 2.
Name three sources of fresh water.
Answer:
Three freshwater resources are: river, lakes and ponds.
Question 3.
What is the effect of deforestation on rainfall?
Answer:
Deforestation results in less rainfall.
Question 4.
State two reasons that are leading to clearing of forests.
Answer:
Growth in population and setting up of factories
Question 5.
State one utility of dams.
Answer:
Prevention of flood
E. Answer the following Questions.
Question 1.
State three factors responsible for water scarcity?
Answer:
Following are the three factors responsible for water scarcity:
(a) Increased population
(b) Environmental degradation
(c) Industrialization
Question 2.
How does setting-up of factories affect the groundwater level?
Answer:
Many industries use a large quantity of water. They exploit groundwater for this. It has resulted in depletion of groundwater.
Question 3.
State two ways to do rainwater harvesting?
Answer:
Two methods of rainwater harvesting are as follows:
(a) By collecting rainwater in underground tank.
(b) Allowing rainwater to seep into the ground.
Question 4.
How should the fields be irrigated to reduce wastage of water?
Answer:
Sprinkler or drip irrigation should be used in farms to avoid wastage of water. Over irrigation of crops should be avoided.
Question 5.
State any three ways of conserving water at home.
Answer:
Three ways of conserving water at home are as follows: e Turn off tap after using it.
- Do not keep the tap running while brushing and washing hands.
- Use a bucket instead of a shower while bathing.
Value Based Questions
Question 1.
What reason may have been given by Apama’s mother?
Answer:
Aparna’s mother may have told her about the importance of saving water.
Question 2.
State the values displayed by Apama and her mother.
Answer:
Apama’s mother showed concern for water conservation. Aparna showed respect for elders.
Question 3.
Suggest another way in which the used water could have been utilized.
Answer:
The water could have been utilized for mopping the floor.
Something To Do
Question 1.
Prepare a questionnaire about usage of water in daily life. Interview your friends/neighbours with the help of the questionnaire. Discuss the findings in the class with your teacher and friends. A few Question uestions are given below as samples:
(a) How do you wash your vehicle?
(b) How many buckets of water do you use for bathing?
(c) How do you water the plants?
You can frame more such questions for the questionnaire.
Answer:
Do it yourself.
Question 2.
Celebrate ‘Water Conservation Day’ in your class. Divide the class into 4-5 groups. Each group should be given a responsibility, like making posters and slogans, putting these posters/ slogans near water taps and bulletin boards in the school, staging a play, etc. to highlight the need for water conservation.
Answer:
Do it yourself.
Question 3.
Look at the pictures given below. Put a tick for the picture which shows saving of water and a cross for the picture which shows wastage of water.
Answer:
- Figures (a) and (c) shows conservation of water.
- Figures (b) and (d) shows wastage of
DAV Class 4 Science Chapter 8 Solutions – Water Scarcity and Conservation of Water
I. Multiple Choice Questions:
1. Which of the following is another name for earth?
(a) Green planet
(b) Blue planet
(c) Red planet
(d) Yellow planet
Answer:
(b) Blue planet
2. How much of total water on earth is available in oceans?
(a) 97%
(b) 87%
(c) 77%
(d) 60%
Answer:
(a) 97%
3. How much of total water on earth is available as freshwater?
(a) 3%
(b) 13%
(c) 23%
(d) 0.03%
Answer:
(a) 3%
4. Industries usually exploit which source of water?
(a) Rivers
(b) Oceans
(c) Groundwater
(d) Rain
Answer:
(c) Groundwater
II. Fill in the blanks:
Question 1.
______ water in the oceans is not fit for our use.
Answer:
Salty
Question 2.
Use of ______ for irrigation can reduce the wastage of water.
Answer:
Sprinkler
Question 3.
Automobiles release ______ and harmful gases in the air.
Answer:
Smoke
Question 4.
______ pipes and taps should be immediately repaired.
Answer:
Leaking
III. Answer the following Questions in one word:
Question 1.
What is the reason for drastic decrease in rainfall and snowfall?
Answer:
Environmental degradation
Question 2.
What is the main source of water for industries?
Answer:
Groundwater
Question 3.
Which method of irrigation can help in reducing wastage of water?
Answer:
Sprinkler
Question 4.
Dams can help in checking which natural disaster?
Answer:
Flood
IV. Answer the following questions in brief:
Question 1.
What is the need for conservation of water?
Answer:
Water is precious for us. If we continue to use it carelessly, a day will come when there will not be enough water to drink. The crops will die due to lack of irrigation. Hence, there is a need for conservation of water.
Question 2.
Explain the main causes of environmental degradation.
Answer:
Causes of environmental degradation:
(a) Deforestation: Forests are being cleared for building houses and for setting up factories. Trees are also being cut to be used as timber.
(b) Air pollution: Increased number of vehicles in the cities means increased level of smoke and harmful gases in the air,
Question 3.
Suggest some steps to conserve water on a larger scale.
Answer:
Water can be conserved on a larger scale in following ways:
- Sprinkler or drip irrigation should be used in farms to avoid wastage of water.
- Proper management of water resources should be promoted to help conservation of water.
- Dams should be constructed to check floods so that water could be conserved.
Question 4.
Explain rainwater harvesting.
Answer:
Collection of rainwater for future use or for recharging groundwater is called rainwater harvesting. For this, rainwater from rooftops should be collected in underground tank. This can be used after purification. This can also be used for recharging groundwater.
Question 5.
What are the effects of environmental degradation?
Answer:
Effects of environmental degradation:
- This has resulted in less rainfall and snowfall. Thus, there is less availability of water. Shortage of rainfall means groundwater is not being replenished.
- Harmful gases in air mix with rainwater and cause acid rain. Acid rain is harmful for animals and plants. It cannot be used for drinking or irrigation.
DAV Class 4 Science Chapter 8 Notes – Water Scarcity and Conservation of Water
→ Water on Earth:
- Three-fourth of the surface of earth is covered with water.
- 97% of the total water on earth exists in oceans.
- Ocean water is salty and cannot be used for our daily needs.
- Just 3% of the total water on earth is in the form of fresh water.
- This means a limited amount of water is available for our use.
→ Factors Causing Shortage of Water
- Population: Demand for water has increased with the increase in population.
- Environmental Degradation: Various human activities have resulted in environmental degradation.
Causes of environmental degradation:
- Deforestation: Forests are being cleared for building houses and for setting up factories. Trees are also being cut to be used as timber.
- Air pollution: Increased number of vehicles in the cities means increased level of smoke and harmful gases in the air.
Effects of environmental degradation:
- This has resulted in less rainfall and snowfall. Thus, there is less availability of water. Shortage of rainfall means groundwater is not being replenished.
- Harmful gases in air mix with rainwater and cause acid rain. Acid rain is harmful for animals and plants. It cannot be used for drinking or irrigation.
Setting up of factories: Many industries use a large quantity of water. They exploit groundwater for this. It has resulted in depletion of groundwater.
→ Need for Conserving Water: Water is precious for us. If we continue to use it carelessly, a day will come when there will not be enough water to drink. The crops will die due to lack of irrigation. Hence, there is a need for conservation of water.
→ Ways to Conserve Water
- Turn off tap after using it.
- Do not keep the tap running while brushing and washing hands.
- Use a bucket instead of a shower while bathing.
- Take only as much water in a tumbler as you want to drink.
- Do not throw leftover water in the sink. Use it for plants.
- Leaking pipes and taps should be immediately repaired.
Water can be conserved on a larger scale in following ways:
- Sprinkler or drip irrigation should be used in farms to avoid wastage of water.
- Proper management of water resources should be promoted to help conservation of water.
- Dams should be constructed to check floods so that water could be conserved.
→ Rainwater harvesting: Collection of rainwater for future use or for recharging groundwater is called rainwater harvesting. For this, rainwater from rooftops should be collected in underground tank. This can be used after purification. This can also be used for recharging groundwater.