THE HYDROLOGIC CYCLE

Water evaporates. It travels into the air and becomes part of a cloud. It falls down to earth as precipitation. Then it evaporates again. This repeats over and over again in a never-ending cycle. This hydrologic cycle never stops. Water keeps moving and changing from a solid to a liquid to a gas, over and over again.

Precipitation creates runoff that travels over the ground surface and helps to fill lakes and rivers. It also infiltrates or moves downward through openings in the soil to replenish aquifers under the ground. Some places receive more precipitation than others. These areas are usually close to oceans or large bodies of water that allow more water to evaporate and form clouds. Other areas receive less precipitation. Often these areas are far from water or near mountains. As clouds move up and over mountains, the water vapor condenses to form precipitation and freezes. Snow falls on the peaks.