Why the Water Cycle is Important.

The Water CycleHumans and the Water Cycle

The Water Cycle

• Seas, oceans, lakes, and rivers cover about seventy-five percent of the Earth’s surface.

• The Earth’s water changes form and moves through the environment in a process we call the water cycle.

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• The heat of the sun changes water on the Earth’s surface into water vapor. This process is called evaporation.

• As the warmed vapor rises, it reaches air that is much colder. At this point the vapor changes back into liquid form. This process is called condensation. These water droplets join together and form clouds.

• If enough droplets form, their weight and gravity causes them to fall back to Earth. This is called precipitation.

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• All living things on Earth need water to survive.• Most get the water they need by drinking water

or foods that contain water.• Plants and animals also put water back into the

environment. We learned plants give off water through their stomata through the process of transpiration. Animals release water when they sweat/perspire, through their breathing, and when they release urine.

Things to think about

• What are the main processes in the water cycle?• 1.

• 2.

• 3.

• 4.

Explain what is going on here…

• Why is there water on the outside of this glass I am showing you?? Write a 1-2 sentence answer on your notes……

Humans and the Water Cycle

• The amount of water on the planet is basically what it was billions of years ago. The water cycle was adequate for the living things that lived long ago.

• Now, the demand for water grows as we need water for cooking, cleaning, bathing, growing crops, feeding livestock, and making materials such as plastics, aluminum, and paper.

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• Most of the Earth’s water is made up of salt water.• Less than one percent of the Earth’s fresh water

can be used because it is frozen in ice caps and glaciers.

• Our freshwater comes from water that flows underground.

• This water can become contaminated by things that occur on the top layers of the Earth.

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• Rainwater running off the land can “pick up” harmful chemicals like oil and road salt and wash it into lakes and rivers.

• Runoff from fertilizers and pesticides can contaminate groundwater supplies.

• Dumping chemicals like oil or paint onto the ground can cause groundwater supplies to be polluted.

Ways to conserve water

• Everyone can help to protect and conserve our freshwater supply.

• Using less water when you brush your teeth, wash clothes and dishes or bathe will save hundreds of gallons daily.

• Washing machines and toilets have been developed that use less water when you use them.

• Watering plants when it is cooler outside instead of the hottest part of the day means you use less water to help the plants grow. Water plants only when they need it.

• Keeping the soil moist by placing mulch on the top of the dirt holds water in and prevents over evaporation.

Ways we can conserve water.

• Here is a short video about how we can conserve water.

Welcome to Discovery Education Player.url

Think about it…..

• 1. Take out your anticipation sheet and now complete the bottom half of the sheet. See if any of your answers have changed.

• 2. On the back of the paper, respond to the following statement in a well written paragraph:

• Write a plan for either your home or our school to conserve and protect our water. Be specific and think of things that can be started right away to help protect our water supply.

• When finished, please put the assignment in your binder with your other notes.