Water Cycle

Water Cycle

Water States

solid ice

liquid water

steam or vape


Water State Transitions

solid ice to

  • ice: moving
  • water: melting
  • steam: sublimation
  • plasma: ionisation

liquid water to

  • ice: freezing
  • water: flowing
  • steam: vaporization
  • plasma: ionization

gaseous steam to

  • ice: deposition
  • water: condensation
  • steam: streaming
  • plasma: ionization

plasma to

  • ice: deionization
  • water:”
  • steam:”
  • plasma:”

Water Species


Sweet or fresh

Ice comes in many different chrystalline structures or phases.

Water Distribution

The total volume of water on Earth is estimated at 1.386 billion km³ = 333 million cubic miles, with 97.5% being salt water and 2.5% being fresh water.

Of the fresh water, only 0.3% is in liquid form on the surface. In addition, the lower mantle of inner earth may hold as much as 5 times more water than all surface water combined (all oceans, all lakes, all rivers).

The storehouses for the vast majority of all water on Earth are the oceans.

It is estimated that of the 332,500,000 mi3=1,386,000,000 km3 of the world’s water supply, about 321,000,000 mi3=1,338,000,000 km3 is stored in oceans, or about 97%.

Today most fresh water exists in the form of ice, snow, ground water and soil moisture, with only 0.3% in liquid form on the surface.

Of the liquid surface fresh water, 87% is contained in lakes, 11% in swamps, and only 2% in rivers.

Small quantities of water also exist in the atmosphere and in living beings.

Water Stores

The residence times of waters in these stores differ.


  • moisture
  • clouds



  • Soil
  • Rivers
  • swamps
  • Lakes
  • glaciers


  • Aquifers
  • Channels
  • Porous Rocks


  • Hydroxyl

Water Flows


Condensed water vapor that falls to the Earth’s surface. Most precipitation occurs as rain, but also includes snow, hail, fog drip, graupel, and sleet. Approximately 505,000 km3 (121,000 cu mi) of water falls as precipitation each year, 398,000 km3 (95,000 cu mi) of it over the oceans. The rain on land contains 107,000 km3 (26,000 cu mi) of water per year and a snowing only 1,000 km3 (240 cu mi). 78% of global precipitation occurs over the ocean.

Snow and Ice Melt

The runoff produced by melting snow and ice.


The variety of ways by which water moves across the land. This includes both surface runoff and under ground runoff.


The flow of water from the ground surface into the ground. Once infiltrated, the water becomes soil moisture or groundwater. A recent global study using water stable isotopes, however, shows that not all soil moisture is equally available for groundwater recharge or for plant transpiration.

Subsurface flow

The flow of water underground, in the vadose zone and aquifers. Subsurface water may return to the surface (e.g. as a spring or by being pumped) or eventually seep into the oceans. Water returns to the land surface at lower elevation than where it infiltrated, under the force of gravity or gravity induced pressures. Groundwater tends to move slowly and is replenished slowly, so it can remain in aquifers for thousands of years.


The transformation of water from liquid to gas phases as it moves from the ground or bodies of water into the overlying atmosphere. The source of energy for evaporation is primarily solar radiation. Evaporation often implicitly includes transpiration from plants, though together they are specifically referred to as evapotranspiration. Total annual evapotranspiration amounts to approximately 505,000 km3 (121,000 cu mi) of water, 434,000 km3 (104,000 cu mi) of which evaporates from the oceans. 86% of global evaporation occurs over the ocean.

It is estimated that the oceans supply about 90% of the evaporated water that goes into the water cycle.


The state change directly from solid water (snow or ice) to water vapor by passing the liquid state.


This refers to changing of water vapor directly to ice.


The movement of water through the atmosphere. Without advection, water that evaporated over the oceans could not precipitate over land.


The transformation of water vapor to liquid water droplets in the air, creating clouds and fog.


The release of water vapor from plants and soil into the air.


Water flows vertically through the soil and rocks under the influence of gravity.

Porous Rock

Magmatic Transition

Under high pressure and temperature transition to hydrogen, oxygen and hydroxyl ions and storage in

Water enters the mantle via subduction of oceanic crust. Water returns to the surface via volcanism.