Water Chapter 11, Section 1

Objectives How does the location of water on the Earth’s surface and the condition of the atmosphere affect its path through stages of the water cycle? How does the amount of saltwater differ from the amount of freshwater on the earth? How does the water continually move through the water cycle?

Earth’s Water -71% of Earth is made up of Water. 97% of the Earth’s water is salt water that is found in oceans.

Fresh Water on the Earth 3% of the Earth’s water is fresh water. Less than 1% of all the water on Earth is fresh water that humans can use.

Location of Fresh Water Available for Human Use: Ice masses near the Poles Rivers and Lakes Water Vapor in the Atmosphere Below the Earth’s surface (groundwater) (More fresh water is located underground than in the Earth’s Rivers and lakes.)

Water Cycle The Water Cycle is the continuous process by which water moves through the environment.

Energy Source for the Water Cycle: The sun is the source of energy that drives the water cycle.

Water Cycle Processes: Evaporation Condensation in Clouds Precipitation Runoff Transpiration Percolation/infiltration

Water Cycle Processes: Evaporation: The process by which molecules at the surface of a liquid absorb enough energy to change to a gaseous state. (Molecules of water escape from a puddle, a lake, a stream, or a droplet of water.)

Water Cycle Processes: Condensation: Clouds form as the water vapor cools.

Water Cycle Processes: Precipitation: As more water vapor condenses, the water droplets in a cloud eventually become so heavy that they fall back to Earth.

Water Cycle Processes: Runoff: When precipitation falls on land, some runs off the surface of land into rivers and lakes.

Water Cycle Processes: Transpiration: When plants release water to the air.

Water Cycle Processes Infiltration/Percolation: water soaks back into the ground like water in a sponge.

Where do we get our freshwater?

Water Pollution