Pg. 1
The Hydrologic Cycle and Water Resources
🌿 Earth System Sciences 🌿
“Water in all forms is the most important resource on Earth”
The Hydrologic Cycle
The hydrologic cycle includes a continuous circulation of water (H2O) within the Earth and the Atmosphere.
Ultimately, the water cycle as a whole is the motion of water between Earth’s surface and the atmosphere.
This water cycle is determined by numerous processes:
● Evaporation
○ The change of liquid to a gas. Sun heats
up droplets of water, forming vapor.
The water then enters the atmosphere.
● Transpiration
○ Water enters plants through the roots.
The water proceeds to evaporate
through miniscule pores in leaves,
leaving non-water material behind in
the plant. This forms purified water.
● Condensation
○ Opposite of vaporization.
○ When water turns from a vapor to a
liquid.
■ Drives processes such as cloud
formation.
■ Usually occurs when a surface
is cold, and water vapor collects as droplets.
● Precipitation
○ Water in all forms (hail, rain, sleet, snow) that falls from the atmosphere and reaches the
Earth’s surface.
○ When clouds get too large and water droplets grow larger in the clouds, the threshold for
the amount of water a cloud can carry is exceeded, and precipitation begins.
● Run-off
● Vaporization
○ A process in which water in its liquid form turns into a vapor state.
The Soil-Water-Budget is the role water plays and where water is at any given time.
Formula: P+I-RO-D-E-T= (change in soil water storage.
P: Precipitation
I: Irrigation
RO: Run-off
D: Drainage
E: Evaporation
The Hydrologic Cycle and Water Resources
🌿 Earth System Sciences 🌿
“Water in all forms is the most important resource on Earth”
The Hydrologic Cycle
The hydrologic cycle includes a continuous circulation of water (H2O) within the Earth and the Atmosphere.
Ultimately, the water cycle as a whole is the motion of water between Earth’s surface and the atmosphere.
This water cycle is determined by numerous processes:
● Evaporation
○ The change of liquid to a gas. Sun heats
up droplets of water, forming vapor.
The water then enters the atmosphere.
● Transpiration
○ Water enters plants through the roots.
The water proceeds to evaporate
through miniscule pores in leaves,
leaving non-water material behind in
the plant. This forms purified water.
● Condensation
○ Opposite of vaporization.
○ When water turns from a vapor to a
liquid.
■ Drives processes such as cloud
formation.
■ Usually occurs when a surface
is cold, and water vapor collects as droplets.
● Precipitation
○ Water in all forms (hail, rain, sleet, snow) that falls from the atmosphere and reaches the
Earth’s surface.
○ When clouds get too large and water droplets grow larger in the clouds, the threshold for
the amount of water a cloud can carry is exceeded, and precipitation begins.
● Run-off
● Vaporization
○ A process in which water in its liquid form turns into a vapor state.
The Soil-Water-Budget is the role water plays and where water is at any given time.
Formula: P+I-RO-D-E-T= (change in soil water storage.
P: Precipitation
I: Irrigation
RO: Run-off
D: Drainage
E: Evaporation
