Water O' Water Chapter Notes | EVS for Class 3 PDF Download

Water

Water is a valuable natural resource. It's a clear, tasteless, and odorless substance that covers about 71% of the Earth's surface. Water is super important for life as we know it. It's essential for living things to survive because it's involved in so many processes, like hydration, photosynthesis, and regulating temperature. Plus, it's really good at dissolving stuff, which makes it great for transporting nutrients and waste around living organisms.

Water can exist in three states: 

• solid (ice)
  
• liquid (what we usually think of as water)
  
• gas (water vapor)
  

Why we need Water?

• For Earth: Water is like a big superhero for our planet. It helps keep everything in balance. It shapes the land through erosion and weathering, carves out rivers and canyons, and fills up oceans and lakes. Plus, it helps regulate the temperature of the Earth, kind of like a natural air conditioner.
• For Humans: We need water to survive! Our bodies are made up of about 60% water, so we need it to stay healthy. We use water for drinking, cooking, cleaning, and even making stuff like clothes and electronics. It also helps our bodies digest food, transport nutrients, and regulate our temperature. Without enough water, we can get dehydrated, which is not fun.
• For Animals: Just like us, animals need water to live. They drink it to stay hydrated and healthy. But water is also home to lots of animals, like fish, frogs, and turtles. They live in rivers, lakes, and oceans, so without water, they wouldn't have a place to call home.
• For Plants: Plants also need water to survive and grow. They soak it up through their roots and use it to make food through a process called photosynthesis. Water helps plants transport nutrients from the soil, cool themselves down, and even stand up straight! Without water, plants would wither and die.

Quantifying water usage 

Quantifying water usage means figuring out how much water we use and for what purposes. It's like keeping track of how many gallons of water we use every day and where that water goes.

We use water for lots of things, like drinking, cooking, bathing, watering plants, washing clothes, and even making stuff in factories. By quantifying water usage, we can understand how much water we need, where we can save water, and how to manage water resources better.

• Saving water is crucial because it ensures there's enough for everyone, protects ecosystems, saves energy and money, and prepares us for the future as the population grows.

Water Sources

Water sources are places where we get water from, like rivers, lakes, groundwater, and even oceans. Accessibility means how easy it is for people to get to and use water.

There are a few different sources where we get water from:

• Surface Water: This includes water that we see on the surface of the Earth, like rivers, lakes, and reservoirs. Surface water is usually collected and treated before it's sent to our homes for drinking or used for other purposes.
• Groundwater: This is water that's stored underground in spaces between rocks and soil. We get groundwater by drilling wells deep into the ground. Groundwater can be pumped up to the surface for drinking, irrigation, and other uses.
• Rainwater: When it rains, water falls from the sky and can be collected for use. Some people have systems to collect rainwater from their roofs and store it in tanks for watering plants or other non-drinking purposes.
• Desalinated Water: In some places, especially where there's not a lot of freshwater available, they use a process called desalination to turn salty ocean water into fresh water that people can drink and use.

Each of these sources has its own advantages and challenges, and they're all important for providing us with the water we need to live and thrive.

Water Storage and Usage:
Water storage is about keeping water in containers or reservoirs for later use. It's like saving water for when we need it most. We store water in tanks, reservoirs, lakes, and even underground in aquifers. It's really important to manage water storage carefully to make sure we have enough water for everyone and that it stays clean and safe to use. 

Which Container has more Water?

To determine which container has more water, you would compare their water levels. If one container has a higher water level than the other, it means that it contains more water. It's like comparing two glasses of water: if one glass is filled to the brim while the other is only half full, the first glass has more water.

For Example:

Imagine Glass 1 is a big, tall glass, and Glass 2 is a smaller, shorter glass. 

• Even though Glass 2 might be filled to the top, because it's shorter, it can hold less water compared to Glass 1, which is taller and can hold more water. 
• So, even if Glass 2 is filled to its top, Glass 1, being bigger, can still hold more water because it has more space inside. 
• It's like comparing a big bucket to a small cup; even if both are filled to the brim, the bucket holds more water because it's bigger.