Natural Sources of Water for Class 4 EVS
- Water is very essential for every living being. Rain is the ultimate source of water on Earth. Seas, oceans and rivers are the natural sources of water.
- Rainwater helps maintain the level of surface and underground water.
- Rivers, lakes, wells and underground water are sources of freshwater. At the same time, the seas and oceans are saltwater sources.
- Visit the following link to know more about water and its resources
Importance of Water Conservation
Question 1:
Why Are Dams Built?
Answer:
- Humans build dams over rivers which act as artificial water bodies.
- Dams have a massive reservoir where the river water can be stored and diverted in different areas apart from the river's route.
- Also, this water is used to produce hydroelectricity.
Question 2:
What Is the Importance of Groundwater? Why Is It Essential When It Is Not Readily Available for Use.
Answer:
- Groundwater is a significant source of fresh water after rivers and lakes.
- The underground water is pumped with the help of bore wells and used for domestic and agricultural purposes.
- The level of groundwater affects the level of water in lakes and wells. The lower the groundwater level, the lower the water level in wells and lakes.
Question 3:
What Are the Causes of Water Pollution?
Answer:
- Around 1500 substances in different forms are recorded as pollutants in freshwater.
- The water gets polluted due to the following factors:
- Waste and chemicals are released from industries and factories.
- Dumping of sewage and garbage in water bodies.
- Overuse of detergents and cleaning chemicals which washes off to the water bodies.
- Overuse of fertilisers and pesticides in agricultural fields, which, when reaching the water bodies, pollute them.
Question 4:
How Does Water From Farms and Sewage Pipelines Make the River Water Unfit? Does It Affect the Plants and Animals in the Water Bodies?
Answer:
- The water from farms and sewage pipelines is full of chemicals and pollutants.
- These chemicals degrade the water quality in the water bodies, making it unsuitable for use.
- Also, due to fertilisers washed off, enormous water plants grow on the surface of the water leading to overconsumption of oxygen available in the water.
- It affects the animals in the water body and sometimes leads to migration or death.
Question 5:
What Is ‘Hard Water’ and ’Soft Water?
Answer:
- When the water contains a higher amount of minerals like calcium and magnesium in it, it is called hard water.
- Due to the presence of minerals, it tastes different.
- Soaps and detergents do not dissolve well in hard water; hence less foam is formed while using hard water. Underground water in some places is hard water.
- Soft water, however, contains very few or no minerals. It is mostly tasteless. Example: rainwater.
Question 6:
In Some Places, You Get Plenty of Water in Wells, but in Others, You Do Not Get Any. Explain Why.
Answer:
- The level of water in wells depends on the level of underground water.
- In the areas with open grounds that are not covered with cemented coverings, the rainwater is absorbed well by the soil, leading to the recharging of the aquifer.
- On the other hand, the covering of bricks and cemented roads do not allow the water to seep down the soil, leading to a low groundwater level.
- Therefore, in some places, you get plenty of water in wells, but in others, you do not get any.
Question 7:
What Are the Effects of Flood?
Answer:
The effects of floods are as follows:
- Loss of life and livestock.
- Damage to the crops.
- Scarcity of potable water.
- The onset of infectious diseases like diarrhoea and typhoid.
- The onset of infectious diseases like diarrhoea and typhoid.
Uses of water
Question 1:
What Will Happen if the ‘Sedimentation’ or ‘Aeration’ Are Done Before ‘Filtration’ in Wastewater Treatment?
Answer:
- The wastewater comprises different types of waste that must be segregated before treatment.
- Filtration helps remove large insoluble waste at the very first step, leading to a considerable decrease in the garbage in the wastewater.
- This decrease in waste helps in the efficient processing of further steps.
Question 2:
What Is Hydroelectricity? How Is Hydroelectricity Produced?
Answer:
- Most hydroelectricity generating plants are equipped with a machine called a turbine.
- The water from a height is allowed to fall on these turbines, making them rotate at a considerable speed.
- These turbines are attached to generators which produce electricity due to the rotation of turbines.
Question 3:
The Farmer Makes Trenches in the Farm Before Sowing the Seeds. What Is the Purpose of Doing This?
Answer:
- Making the trenches in the farm and sowing the seeds on top aids the flow of water.
- Trenches in the field allow the even supply of water to all the seeds and later to the plants.
- It prevents water logging and promotes a good yield of crops.
Question 4:
How Does Water Help in Extinguishing Fire?
Answer:
- The basic idea followed while extinguishing a fire is to cut the supply of oxygen to the burning substance.
- As the water is poured over a substance, it cuts the supply of oxygen and extinguishes the fire.
- But this method is ineffective in case of fire caused due to oil.
- Also water should never be used in case of a fire caused due to short circuit or chemical fire. It may worsen the situation.
Question 5:
What Happens to Our Bodies if We Do Not Drink Water for Too Long?
Answer:
The effects of lack of water in our body are as follows:
- Feeling of thirst, dehydration and reduced urination.
- Dry mouth, weakness of muscles and dizziness.
- Severe effects like unconsciousness, dry skin and lack of sweating can be observed in the long run.
Question 6:
List the Difference Between Drip Irrigation and Sprinkler Irrigation?
Answer:
- Both these types of irrigation are practised to minimise water loss during irrigation. The main differences are as follows:
| Drip Irrigation | Sprinkler Irrigation |
|---|---|
| Water is supplied in the form of drops through porous water pipes. | Water is supplied which the help of sprinklers attached to the long pipes laid on the ground. |
| It is helpful for small vine or vegetable crops grown on a small land. | They are used for more giant farms. |