Presentation on theme: "Ms.Aja 5 th Grade. Fresh water Less than 3/100 of Earth’s water is fresh water. Used for drinking, cooking an cleaning. Also used to grow crops, make."— Presentation transcript:
Fresh water Less than 3/100 of Earth’s water is fresh water. Used for drinking, cooking an cleaning. Also used to grow crops, make electricity and make many products. Almost all of it starts as rain or snow. There is a limited amount of fresh water. It should be conserved as much as possible.
Groundwater Rain or melted snow that soaks into the ground is called groundwater. The layer of rock and soil that groundwater occupies is an aquifer The top level of groundwater is an aquifer is the water table. This level change during the year depending on the amount of rainfall. It can also get low when water is pumped for wells.
Rivers and Lakes Water from rain and melting snow flows downhill into small streams. Most rivers eventually flow into oceans. The area from which water drains into a river is called the river’s watershed. If chemicals go into the watershed, they may be carried into the river. Rain water may erode soil from fields. This could ruin ecosystems. Lakes form when the water collects in the low spot. A reservoir is an artificial lake that forms behind a dam.
Ice About 7/10 of Earth’s fresh water is frozen into ice. This is hard for people to use. Glaciers and ice sheets are smaller areas of ice. Ice tops are bigger. Valley glaciers are found in the valleys of high mountains. Glaciers and ice sheets form when each year’s snowfall is greater than the amount that melts. When ocean water freezes, the resulting ice is not salty. The salt is pushed out of the ice crystals as they form. This causes the water around the new ice to become more salty.
Getting Water to Homes Some towns get it from groundwater Water could have bacteria. Water needs to be purified. Pg. 206-207 Water is pumped, chemicals are added, The particles become heavy enough to sink. Water then passes through filters. Water is then treated and small amounts of chlorine are added. Bacteria is killed
Questions How is fresh water different from ocean water? How much of Earth’s fresh water is in ice sheets and glaciers? How do icebergs form?
Answers Ocean water has much more dissolved salt. It is not used for drinking, cooking or cleaning. 7/10 The break off from glaciers or ice sheets