Building the Water Cycle Diagram

Activity Source: 

Based on the USGS Water Cycle Diagram
The PDF file of the activty can be found here

LESSON OVERVIEW

Even before they have had any instruction about the water cycle, students have likely had real life experiences with where water is stored (generally called “pools”) and how it moves through the environment (generally called “fluxes”). This lesson uses an unlabeled version of the 2022 USGS Water Cycle Diagram to activate and assess prior knowledge about the water cycle. As the lesson progresses, key vocabulary is added to the diagram and the diagram is revisited periodically so students can continually build their knowledge of the water cycle. Once students are familiar with the different pools and fluxes of water, they will explore an online interactive displaying the various sizes of pools and fluxes.

BACKGROUND*

The water cycle describes where water is on Earth and how it moves. Water is stored in the atmosphere, on land, and below the ground. It can be a liquid, a solid, or a gas. Liquid water can be fresh or saline (salty). Water moves between the places it is stored. Water moves at large scales; through watersheds, the atmosphere, and below the Earth's surface. Water moves at very small scales too. It is in us, plants, and other organisms. Human activities impact the water cycle, affecting where water is stored, how it moves, and how clean it is.

Learn more about the water cycle (including pools, fluxes, how humans alter the water cycle, climate change impacts, and water availability) from the U.S. Geological Survey Water Science School

*Background information reproduced, with permission, from USGS.

ACTIVATE PRIOR KNOWLEDGE

1. Have students explore and annotate the unlabeled water cycle diagram (either on their own, or in a think‑pair‑share exercise). Ask students:

a. What do you notice?

b. What components of the water cycle can you identify in this diagram?

i. Consider where water might be stored or held (pools) within this diagram.

ii. Consider how water might move (fluxes) between pools.

c. Is there anything on the diagram that makes you wonder what it is, what it does, and/or its role in the water cycle? If so, place a question mark next to the object or location. 

2. Project the unlabeled diagram onto a whiteboard or print out a large poster‑sized copy (optionally laminated).

a. Have a classroom discussion while students share their thoughts about (and possibly while labeling) the diagram.

b. Make a word bank of the vocabulary that students are using while describing the diagram. Keep the list up for students to see.

REINFORCE LEARNING

3. As you teach about content related to the water cycle and specific elements of the hydrosphere, revisit the water cycle diagram, adding vocabulary to the word bank and making connections to other Earth systems (i.e., geosphere, biosphere, atmosphere).

4. As often as you would like, have students revisit and update their annotated water cycle diagram. Ask students to add newly acquired vocabulary onto their diagram. Discuss their annotations and the meaning of the terms with a partner or whole class.

EXPLORE RELATED DATA

5. Compare the sizes of the different pools and fluxes.

a. Print the terms associated with types of pools with which your students are familiar. Cut the terms apart so there is one term per card. Ask students to arrange the pools in order on a global scale from the type of pool where the most water (greatest volume) would be found to the pool with the least water.

b. Repeat with the different types of fluxes.

6. Visit the USGS Visualization Lab’s interactive chart exploring the size of pools and fluxes of water: Poolsand Fluxes in the Water Cycle.

a. Depending on the student level, choose to view the data on a logarithmic or linear scale. If not discussing scale, it is recommended to use only the logarithmic graph. 

i. If using both graphs, start with the linear scale and ask students what they notice.

ii. Show the graph using the logarithmic scale and have students describe what they notice or wonder about.

iii. Discuss the different scales in relation to the water cycle. For example, the “Ocean – deep" pool has substantially more water than all other pools and viewing the data on a linear scale makes this extremely apparent. However, the differences in amounts of the smaller pools is not discernable on a linear scale.

iv. There is the option to click on each pool and flux to see the volume reported numerically, as well as a definition of that pool or flux.

b. Depending on the student level, choose to view the data with or without ranges. Discuss with students the benefits of seeing the ranges and not.  

c. Examine the amount of water stored in the different pools, identified in brown, and the amount in each flux, identified in green. Ask students to compare the results to the way they arranged the cards in step 5. 

d. Optionally, display the relative amounts of water in the seven groups of pools following the information in the table below.

EXTENSION

Depending on student abilities, consider having the students use the interactive chart or associated datatable to make the calculations themselves and then create their own display showing the relative size of the pools. Note that their calculations might differ from those on the table below. Have them consider why there might be differences (e.g., different methods used for the estimates).

WATER VOLUME OF POOLS AND FLUXES

Grouped Pools

Volume Estimate* (km3)

Percentage

Total Volume (mL), assuming total World Water = 500.0 mL

Oceans

1,206,000,000 + 134,000,000

96.48%

482.4 mL

Glaciers and other frozen water

25,800,000 + 207,000 + 2,900

1.87%

9.4 mL

Groundwater and soil moisture

22,600,000 + 54,100

1.63%

8.2 mL

Lakes

108,000 + 94,700 + 10,800

0.02%

0.1 mL

Wetlands

14,100

<0.01%

 

Atmosphere

10,000 + 3,000

<0.01%

 

Rivers

1,900

<0.01%

 

Total

1,388,906,500

 

 

*The volume estimate is adapted from Abbott et al. (2019). Abbott et al. note that the estimate for each pool or flux "represents the most recent or comprehensive individual estimate".

ASSOCIATED RESOURCES

  •  To learn more about the new USGS water cycle diagram and to explore the full, interactive USGS Water Cycle Diagram, please visit water-cycle (usgs.gov).
  • Visit WaterPoolsandFluxesDataTablesto view the data in table form that is used in the Pools and Fluxes Interactive.
  •  View the full list of terms and their definitions in the GlossaryofWaterCycleTermsfrom USGS.
  • To view the unlabeled version of the USGS Water Cycle Diagram, click here
  • To view the labeled version of the USGS Water Cycle Diagram, click here
  • View the list of Water Cycle Diagram terms here

STANDARDS

NGSS
SEP: Developing and Using Models; Analyzing and Interpreting Data
DCI: The Roles of Water in Earth’s Surface Processes; Earth’s Materials and Systems; Weather and Climate
CCC: Systems and System Models; Energy and Matter; Scale, Proportion, and Quantity; Structure and Function
 
SDGs
2: Zero Hunger
6: Clean Water and Sanitation
11: Sustainable Cities and Communities
14: Life Below Water
15: Life on Land

Learn more about the United Nation’s Sustainable Development Goals (SDGs) and explore resources for educators from UNESCO: https://en.unesco.org/themes/education/sdgs/material