What is the Water Cycle?

What kinds of water are there? 97% of the water is salt water, and is found in the oceans of the world. Only 3% of the water is fresh water on which we (land animals) depend.

How Much Water is There? Approximately three-fourths of the earth is water.

Where is it found? Oceans Lakes Rivers Clouds Water comes from several obvious places. Oceans Lakes Rivers Clouds Can you think of any more sources?

Where else do we get water? Animals,* plants* and soil, We’re animals, too! Transpiration is what we get from plants, elimination (Sweat, bodily fluids) from animals …and groundwater.

What does sunshine have to do with the water cycle? The sun will shine on water located in various areas making it warmer. This causes the water to eventually turn into vapor. This process is called evaporation.

Evaporation Evaporation occurs when the sun heats water turning it into water vapor. What forms of water vapor have you seen? Have you ever experienced humidity? The vapor leaves its source and rises to become part of a cloud. Heat rises; remember, the water was HEATED to become vapor.

Precipitation The clouds get so full and heavy with water that water droplets in the form of rain, snow, sleet or hail start to fall. It falls onto the ground and into bodies of water like oceans, rivers, lakes, and streams.

Around 32o F When the cloud temperature is really cold, it will snow rather than rain. If the cloud temperature isn’t freezing (32OF), but the air is on the way down, it will sleet or hail.

Mountains and Ice The snow that falls onto mountains may turn into ice because of the extremely cold temperatures at high altitudes. This ice and snow may form glaciers.

Other places, snow may thaw and run-off in the form of streams, brooks, or creeks. Or…

… it may become groundwater. comes from rain, snow, sleet, and hail that soaks into the ground. The water soaks down into the ground because of gravity, passing between particles of soil, sand, gravel, or rock until it reaches a depth where the ground is filled, or saturated, with water. Can you think of any other sources?

Water Tables The area that is already filled with water is called the saturated zone . The top of this zone is called the water table. Makes sense, doesn't it? The top of the water is like a table top! Think of a bucket of water, is it flat? When something is soaking wet, it is saturated.

Aquifers Hold Water Groundwater is stored in the ground by materials like gravel or sand. It's kind of like the earth is a big sponge holding all that water! A space that holds a lot of water, which can be pumped up with a well, is called an aquifer. Commercial wells pump groundwater up from the aquifer and then into pipes* to deliver the water to use in communities. Commercial wells do this, not all others.

Rivers and Streams Run-off or surface water that makes it to rivers and steams carries water to reservoirs, lakes and, finally, to the ocean. Many carry the water thousands of miles. Man-made lakes called reservoirs are created when a dam is built.

Oceans Oceans cover about ¾ of the surface of Earth. When the fresh water travels to the ocean, it mixes with the ocean water and becomes salty. Eventually, the sun shining on the ocean warms the water. Then what will happen?

In the sky The heated water becomes vapor and forms clouds. Then what sometimes happens?

Precipitation!

Note: evaporation from plants is called transpiration. The Water Cycle Note: evaporation from plants is called transpiration.