Water Cycle Processes:
Precipitation is 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 of water fall as precipitation each year, 398,000 km³ of it over the oceans.
Canopy interception is the precipitation that is intercepted by plant foliage and eventually evaporates back to the atmosphere rather than falling to the ground.
Snowmelt refers to the runoff produced by melting snow.
Runoff includes the variety of ways by which water moves across the land. This includes both surface runoff and channel runoff. As it flows, the water may infiltrate into the ground, evaporate into the air, become stored in lakes or reservoirs, or be extracted for agricultural or other human uses.
Infiltration is the flow of water from the ground surface into the ground. Once infiltrated, the water becomes soil moisture or groundwater.
Subsurface Flow is the flow of water underground, in the vadose zone and aquifers. Subsurface water may return to the surface (eg. 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.
Evaporation is 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. Approximately 90% of atmospheric water comes from evaporation, while the remaining 10% is from transpiration.[citation needed] Total annual evapotranspiration amounts to approximately 505,000 km³ of water, 434,000 km³ of which evaporates from the oceans.
Sublimation is the state change directly from solid water (snow or ice) to water vapor.
Advection is the movement of water in solid, liquid, or vapor states through the atmosphere. Without advection, water that evaporated over the oceans could not precipitate over land.
Condensation is the transformation of water vapor to liquid water droplets in the air, producing clouds and fog.
Resources:
Subject: NASA's Observatorium: Hydrologic Cycle
Link: http://observe.arc.nasa.gov/nasa/earth/hydrocycle/hydro2.html
Description: This site contains information on the many processes that work together to keep Earth's water moving in a cycle. These are the five processes at work in the hydrologic cycle, condensation, precipitation, infiltration, runoff, and evapotranspiration, all of which occur simultaneously and, except for precipitation, continuously. There is a section for each process with a detailed explanation
Grade level: Middle School, High School
Resource Type: Tutorial, Illustration
Subject: The Hydrologic Cycle, On-line meteorology guide
Link: http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/home.rxml
Description: On line guide takes you through all components of the Hydrologic Cycle
Grade level: High School
Resource Type: Tutorial, Illustration
Subject: Water Cycle
Link:http://www.kidzone.ws/water/
Description: A simple diagram and explanation of the water cycle
Grade level: Elementary School
Resource Type:Illustration - Scientific, Reference Material
Subject: Water Cycle
Link: http://www.ucar.edu/learn/1_1_2_4t.htm
Description: Students will build a model to simulate parts of the water cycle. They will be able to recognize and explain the essential elements of the water cycle. From this information, they will appreciate that scale models can be an important tool to use in understanding global processes.
Grade level: Middle School, High School
Resource Type: Lab Activity
Subject: Water Cycle
Link: http://www.nationalgeographic.com/xpeditions/lessons/07/gk2/water.html
Description: Splish, Splash, Water's Journey to my Glass. This lesson enables students to explore how water moves through the hydrologic cycle, eventually making its way to their drinking glasses.
Grade level: Elementary School
Resource Type: Lesson Plans
Subject: Water Cycle/ Teachers' Lounge:
Link: http://education.arm.gov/teacherslounge/lessons/alphalessons.stm
Description: Teachers' Lounge/Alphabetical list of lesson plans covering many aspects of the Hydrologic Cycle
Grade level: Middle School
Resource Type: Lesson Plans/ Resources for Teachers
Subject: Water Cycle: Water Education Foundation
Link: http://www.water-ed.org/schoolprograms.asp
Description: The programs teach students about the history, geography and science of water. Students also learn about the difficult political and policy decisions surrounding this complex issue.
Grade level: Elementary School, Middle School, High School
Resource Type: Water Information and Lesson plans
Subject: The Water Cycle
Link: http://ga.water.usgs.gov/edu/watercycle.html
Description: This interactive diagram of the water cycle invites students to click on a part of the cycle to get information about streamflow, surface runoff, freshwater storage, ground-water discharge, ground-water storage, infiltration, precipitation, snowmelt, runoff to streams, springs, condensation, evaporation, transpiration, water in the atmosphere, ice and snow, and oceans
Grade level: Elementary School, Middle School, High School
Resource Type: Illustration - Scientific, Reference Material
Subject: The Water Cycle: Water Storage
Link: http://www.epa.gov/safewater/kids/flash/flash_watercycle.html
Description: This interactive, animated graphic helps explain the water cycle to younger students. The animation, with sound, explains the various parts of the water cycle and show how water moves from one part to another.
Grade level: Elementary School
Resource Type: Illustration - Scientific
Subject: Discover the Water Cycle
Link: http://lvwater.org/tour_cycle.html
Description: This interactive tour of the water cycle allows students to follow a water molecule from a home's plumbing system as it follows different routes through the hydrologic cycle. Students learn about how water is used, treated, and returned to the natural environment where it can cycle through liquid, solid, and gas phases.
Grade level: Elementary School, Middle School
Resource Type: Computer Activity
Subject: The Water Cycle
Link: http://www.utm.edu/departments/cece/old_site/seventh/7I3.shtml
Description: This Classroom Connectors lesson plan discusses the continuous movement of water from Earth to air and back to Earth. Students list areas of the Earth where water circulates, explain evaporation and condensation, list the steps of the water cycle and explain what happens in each step.
Grade level: Middle School
Resource Type: Lesson Plan
Subject: Drinking water and Groundwater (includes Water Cycle)
Link: http://www.epa.gov/safewater/kids/index.html
Description: The site includes water cycle information, lesson plans and activities for both teachers and students
Grade level: Elementary School, Middle School, High School
Resource Type: Classroom Lesson Plans, Games and Activities
Subject: NASA EOS Science Poster Series
Link: http://eospso.gsfc.nasa.gov/eos_homepage/for_educators/eos_posters/index.php
Description: Air, Water, Land and Ice
Grade level: High School
Resource Type: Informative PowerPoint Posters and Supplemental Materials for the classroom
The Water Cycle Movie
This animation illustrates evaporation to condensation to precipitation .....
Movie with text (45 mb) [1]
Movie without text (25 mb) [2]
Movie description & credits [3]
Water Cycle Graphic:[[4]]
![[4]](http://crew.iges.org/CREWindex_files/watercycle.overview.gif){kind=link}
NASA Satellite Missions to Observe the Global Energy and Water Cycle[[5]]
![[5]](http://crew.iges.org/research/waternet/images/fig1.waternet.png){kind=link}
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