How the Water Cycle Works

The Water Cycle also known as the hydrologic cycle is the process in which water is cycled throughout the planet.  Matter is neither created nor destroyed which means that the Earth is basically recycling the water that we use through different processes.  The main processes in the water cycle are precipitation, condensation, evapotranspiration, and evaporation.

The hydrological cycle works because of the three phase changes that water goes through.  These phase changes are gas, liquids, and solids.

water cycle, gas, solid, liquid, condensation, sublimation, freezing, deposition, melting, vaporization, phase change

These phase changes happen at nearly every stage of the water cycle and are generally caused by varying temperatures from the sun.


Water vapor in the sky collects and turns into water particles through the process of condensation.  Once condensation occurs then the process of precipitation can occur.  Precipitation is the process of water droplets falling to the ground as the particles are denser than air particles.  This can occur in various forms such as snow, sleet, rain, or hail. 


Runoff is the next part of the water cycle as water moves from higher elevations to lower elevations.  This can occur during and after a rainstorm or when the weather heats up and snow begins to melt.  As the water droplets move downhill they come together forming streams and rivers.  As streams and rivers flow some of the water is lost in a process known as infiltration and evaporation.  These streams and rivers collect into lakes and oceans which form when the elevation is too low and there isn’t anywhere else for the water to go.


Infiltration is the process in which surface water seeps into the soil.  Similar to runoff, water infiltrates into the soil until it is unable to go any deeper.  This can be caused by various reasons such as the water reaching an impervious layer (layer of dirt in which water can’t pass) such as clay.  When this happens, water collects and forms aquifers.


Bodies of water underground that typically collect as water infiltrates through the soil.  Aquifers are at various depths and are often referred to as ground water.


Evaporation is caused when the heat from the sun heats up water on Earth’s surface and turns the water particles into water vapor.  This water vapor is less dense than air and travels upwards toward the clouds where it once again collects and turns into precipitation.


Transpiration is the process in which water is extracted from plants by the sun through heat.  This occurs by water inside the plant being heated and turned into water vapor.  This water vapor is once again less dense than air and travels out of the plant through pores.  This water then travels upwards to the clouds and collects to form precipitation.

Leave a Reply

Your email address will not be published. Required fields are marked *