The water cycle includes
- Evaporation: The process in which water changes from its liquid state to a vapor or gas state. This occurs when the sun heats up the surface water in oceans, lakes, and rivers and turns it into vapor.
- Condensation: The process in which water vapor cools and changes back into liquid water. This occurs when the cooled water vapor forms clouds in the atmosphere.
- Precipitation: The process in which water falls from the atmosphere to the Earth's surface in various forms, including rain, snow, sleet, or hail. This occurs when the cloud particles combine and become too heavy to stay in the air.
- Runoff: The process in which water flows over the land surface into rivers, lakes, and oceans. This occurs when precipitation cannot be absorbed by the ground fast enough or when water bodies are already at capacity.
- Infiltration: The process in which water seeps into the ground and becomes groundwater. This occurs when precipitation is absorbed by soil and permeable rocks.
- Transpiration: The process in which plants release water vapor into the atmosphere through their leaves. This occurs when plants take up water from the ground and release it through tiny pores in their leaves called stomata.
These processes continuously interact and contribute to the movement and distribution of water on Earth, forming the water cycle.
The water cycle, also known as the hydrological cycle, includes the following steps:
1. Evaporation: This is the process by which water transforms from a liquid state into a vapor or gas state. It occurs when heat energy from the sun causes water bodies such as oceans, lakes, and rivers to turn into water vapor.
2. Condensation: Once water vapor is in the air, it starts cooling down and changes back into the liquid state. This process is known as condensation. It forms droplets that combine to form clouds.
3. Precipitation: When the water droplets in the clouds become too heavy, they fall back to the Earth's surface as precipitation. Precipitation can take various forms, including rain, snow, sleet, or hail.
4. Collection: After precipitation falls, it gathers on the Earth's surface, usually in bodies of water such as lakes, rivers, and oceans. It can also accumulate in the form of snow on land or be absorbed into the ground.
5. Runoff: When the land is saturated with water, excess water flows over the surface and collects in streams, rivers, and eventually makes its way back to the larger bodies of water, such as lakes or oceans. This process is known as runoff.
6. Infiltration: Some of the water that falls to the ground is absorbed into the soil, a process called infiltration. This water may eventually reach underground reservoirs, known as aquifers, and become groundwater.
7. Transpiration: Plants and animals play a significant role in the water cycle through a process called transpiration. Plants absorb water through their roots, and then release moisture into the air through small openings in their leaves called stomata. This water vapor then contributes to the water cycle by condensing and forming clouds.
These steps constantly repeat, creating a continuous cycle of water movement on Earth.