Presentation on theme: "The Water Cycle In this presentation you will: explore the stages of the water cycle ClassAct SRS enabled."— Presentation transcript:
The Water Cycle In this presentation you will: explore the stages of the water cycle ClassAct SRS enabled.
The Water Cycle Water covers the majority of the surface of the earth. Water is vital to life on Earth for two main reasons. Next > Firstly, it makes up 70% of living things. Secondly, it provides an environment for those organisms that live in water.
The Water Cycle Next > Our Water is Millions of Years Old At one time or another, all the water molecules on the planet have been in an ocean, a river, a plant, an animal, a cloud, a raindrop or a glacier. Another interesting fact is that the water we drink today is the same water that the dinosaurs drank millions of years ago!
The Water Cycle Next > Water Can Gain Energy Wherever water is on the surface of the earth, it can be heated by radiation from the sun. The sun provides it with energy. The water can be affected by weather conditions too. For example, water in the oceans will form large waves when a storm is near. This also gives large amounts of energy to the water. Condensation Evaporation Rain
The Water Cycle 1 Which process transfers heat from the sun to the oceans? Question A) Convection B) Radiation C) Conduction D) Correlation
The Water Cycle Next > Evaporation Evaporation is the changing of a liquid to a gas. During the evaporation process, impurities in the water are left behind. As a result, the water vapor that enters the atmosphere is cleaner. Water can evaporate into the atmosphere from oceans, seas, lakes, pools, snow, and living organisms. The energy that the water gains helps it to evaporate.
The Water Cycle Next > Factors that Affect Evaporation The amount of natural evaporation that takes place is affected by the wind. The warmer and drier the wind, the higher the rate of evaporation. The main factor affecting evaporation is temperature. Water evaporates more quickly at higher temperatures.
The Water Cycle 2 Which of the following factors does NOT affect the rate of evaporation? Question A) Temperature B) Mass C) Humidity D) Wind
The Water Cycle Next > Convection When water evaporates, it becomes water vapor. When a gas is heated it expands, its volume gets larger. The sun continues to supply energy so the water vapor (a gas) gets warmer. This makes it less dense than the air above it, so it rises. This upwards flow is called a convection current.
The Water Cycle 3 Why does warm water vapor rise? Question A) Because it is less dense than the air above it. B) Because it is escaping from the ocean. C) Because of evaporation. D) Because it is attracted by clouds.
The Water Cycle Condensation Condensation is the process by which water vapor changes from a vapor to a liquid. As the vapor rises it will also cool down. When it has cooled, it may condense. Next > Water vapor condenses onto small airborne particles to form dew, fog or clouds.
The Water Cycle 4 Which of the following correctly describes the term 'condensation'? Question A) It is the changing of a liquid into a solid B) It is the changing of a gas into a liquid C) It is the changing of a solid into a gas D) It is the changing of a liquid into a gas
The Water Cycle Rain, Snow or Hail If the water drops become large enough, the water will fall from clouds in the form of rain, snow or hail. Clouds contain water vapor and cloud droplets, which are small drops of condensed water. These droplets are much too small to fall out of the cloud, but they are large enough to make the cloud visible. Next > This delivers the atmospheric water back to the Earth. This process is called precipitation.
The Water Cycle Rainfall Most of the rain or snow that falls lands directly back into water. It can then: evaporate again soak into the soil or rock run off the surface. Next > Some of the rain falls onto land.
The Water Cycle Soaking into the Ground Water on the surface soaks into the ground. This depends upon the permeability of the soil or rock. Groundwater tends to move slowly. In some cases, it can take thousands of years to return as surface water. Due to the force of gravity, the water returns to the land surface at a lower point than where it entered. Next >
The Water Cycle Percolation Percolation is the downward movement of water through soil and rock. This occurs below the root zone (the depth of soil penetrated by plant roots). Ground water percolates through the soil in the same way as water fills a sponge. It moves from space to space along fractures in rock or through sand or gravel. Next >
The Water Cycle 5 What name is given to the process of water passing through rocks below the earth's surface? Question A) Evaporation B) Convection C) Condensation D) Percolation
The Water Cycle Run-Off Water that does not soak into the ground or evaporate immediately will run off the land. It will form streams, which in turn form rivers that run into lakes or eventually the oceans. Next > In this way the cycle will then be ready to repeat itself.
The Water Cycle Summary After completing this presentation you should be able to: End > show knowledge and understanding of the stages of the water cycle