Water cycle facts for kids
The water cycle is the cycle that water goes through on Earth.
Water is essential for life as we know it. It is present throughout the Solar System, and was part of the Earth from its formation.
The mass of water on Earth remains fairly constant over time. However, the partitioning of the water into the major reservoirs of ice, fresh water, salt water and atmospheric water is variable and depends on climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere. The processes that drive these movements are evaporation, transpiration, condensation, precipitation, sublimation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor. The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation.
The cycle
- First, water on the surface of the Earth evaporates.
- Then, water collects as water vapor in the sky. This makes clouds.
- Next, the water in the clouds gets cold. This makes it become liquid again. This process is called condensation.
- Then, the water falls from the sky as rain, snow, sleet or hail. This is called precipitation.
- The water sinks into the surface and also collects into lakes, oceans, or aquifers. It evaporates again and continues the cycle.
Humans activities that affect the water cycle
Human activities that change the water cycle include:
- Agriculture
- Industry
- Building dams
- Deforestation
- Removing groundwater from wells
- Water abstraction from rivers
Images for kids
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Diagram of the Water Cycle
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The water cycle
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Many different processes lead to movements and phase changes in water
See also
In Spanish: Ciclo hidrológico para niños
