The Water Cycle The continuous process of water evaporating, condensing, returning to the earth as precipitation, and returning to a water resource.

Where is water? In oceans, rivers, lakes, streams, ponds…Oceans covers 71% of Earth’s surface! (liquid) In the atmosphere as water vapor (gas) In glaciers (solid)

4 Stages Evaporation Condensation Precipitation Runoff Gas Liquid Liquid or Solid Runoff

What Causes Water to Change Phases Within this Cycle? The Sun! Solar Energy!

Evaporation Adding solar energy to water causes the water molecules to move quickly, change to gas (water vapor) and escape from the surface of the earth and rise up into the atmosphere.

Condensation Water vapor is cooled down from the lower temperatures and pressure in the atmosphere Molecules slow down and turn back into liquid water, called condensation These water droplets attach themselves to dust particles and form clouds

Precipitation When the clouds and air currents can no longer support the water particles, they fall to the earth. Any form of water that falls from the sky is considered precipitation

Runoff Once the precipitation falls to the earth, it has to go somewhere! Most will run along the earth’s surface and flow into a water resource