Today, the earth has the same limited amount of water as it had thousands of years ago. Each year more than 500,000 km3 of water evaporates from the oceans. Even so the ocean’s level doesn’t drop because the water is constantly recycled and a returns to the oceans in various forms. That water keeps going around and around and around and around in what we call the “Water Cycle” or “Hydrological Cycle”.
- The water cycle starts when the ocean water is heated up by the sun, turns into a gas called water vapor and rises invisibly into the air. This process is known as evaporation.
- Water vapor rises until it reaches a cooler part of our atmosphere, it cools and turns into clouds. This process is known as condensation.
- When excessive amount of water has condensed in the cloud, the water droplets in the clouds become too big and too heavy for the air to hold them and they drop down to Earth as rain. This process is known as precipitation
- Most of the time clouds drop its precipitation directly into the ocean but some of these clouds are pushed by the winds and drops its precipitation on the landmasses.
- Part of the rainfall soaks underground. This process is known as Some of the infiltrated water is consumed by plants. The rest of infiltrated water supplies groundwater or flows into water courses.
- Part of the rainfall stays on the surface and flow through creeks and rivers back to the ocean. This process is known as
When water reaches oceans the Water Cycle begins all over again.