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The Natural Water Cycle and the Watershed: Gravity and Topography

Learning Experience 2

Big Ideas

This learning experience has multiple big ideas:

Explore and Explain 1

The natural water cycle is a closed loop involving stages and phase changes as water moves through the environment.

Explore and Explain 2

A natural watershed is the area of land from ridge top to ridge top that collects water and drains into the nearest stream, river, lake or other body of water.

Gravity and topography affect the interaction between the natural water cycle and the natural watershed.

Summary

Students will understand how the natural water cycle and the natural watershed interact depends on gravity and topography and how that relates to where they live.

Engage

Take students for a walk outside just after a rainstorm. If it has not rained recently, take some water with you to pour on various surfaces. Examine what happens to the water and have the same discussion. Look for evidence of precipitation (rain) and condensation (clouds). Can they see evidence of infiltration (damp soil?)

Use this student organizing document to write down their observations and make the connection to the water cycle.

Back in the classroom, ask them to draw the four main components of the water cycle (condensation, precipitation, evaporation and runoff) in their Watershed Journal. As students describe what they observed, review the related vocabulary as they complete their diagrams.

Explore and Explain 1

Tap students’ prior knowledge about the sequence and component parts of the natural water cycle by choosing one of the activities :

  • Create a graphic organizer (a foldable) depicting the parts of the natural water cycle
  • Complete this Reading and Analyzing Strategy RAN (modified KWL) Student Worksheet
  • Use blank index cards. On one side write a description of the water cycle. On the other side illustrate the stage(s)

Make a Water Cycle Model

This may be done in small groups or as a class.

This model will be made using 2-liter bottles. This observational activity can be done as a demonstration (one model for the class) or small groups creating their own models.

After observing the water cycle, ask students to identify any real world examples of evidence of the water cycle.

Explore and Explain 2

WHAT IS A WATERSHED?
Students share their initial definitions of a watershed. They will revisit this definition later so have them write the definition in their Journal.

Watershed videos:
 Chesapeake Unscripted: What is a Watershed? (Chesapeake Bay Program on Vimeo.)
→Stop the video (Timestamp: 3:27) before the narrator gives the definition away.

“What is a Watershed? (YouTube)

Complete the Chesapeake video to reveal the definition.

As part of your discussion about the videos, you may use this vocabulary review worksheet..

Watershed Vocabulary Review.

Building a Model of a watershed:

Students will use foil, paper, and markers to build a model of a watershed. Instructions are outlined in the Instructional slide deck and as a student ready copy Student Materials.

As students build their watershed, have students identify the geographic elements in their model.

Have students hypothesize where water might collect during a rain storm or other water event, and make sure those areas are highlighted in blue (see watershed model directions).

To model precipitation, use a spray bottle to gently mist the model with water.

After observing their watershed in action, students may want to revise their definitions of a watershed to include elements of the water cycle. Focus students on how landform features impact the watershed.

Create a Topographic map of a watershed:

Students will build a model of a topographic map. The process involves building a mountain out of clay and slicing it into 2cm sections using dental floss.

This instructional video will demonstrate the topography activity with clay and dental floss.

If you would like more information on topographical maps, check out these resources: Topographic Map Review

Topographic web guide

 

DEVELOP THE CONNECTION

Help students make the connection between the contour lines on a topographic map and water flow. A topographic map shows 3D elevation in two dimensions. Since we know that gravity makes water go down, the contours on the topographic map help us to predict how and where the water will flow.

Combine models to create a mountain range. Students predict how the water would flow in their “watershed” as they did with the crumpled paper demonstration. If time permits, create a new topographic map (slicing with dental floss) of the new mountain range.

For an additional challenge, mix up mountains and contour maps and have students try to figure out which map belongs with which mountain. Review concepts by encouraging students to consider how the lines are different on a gently sloped mountain (big and far apart) from a taller steeper mountain (small circles, close together).

Teacher tip: Need to brush up on how to read a contour map? Check out Topographic web guide

Putting it all together:

Putting it all together: Looking at topographic maps of Philadelphia

Show this video: You Tube: What is Topography?

Roxborough Reservoir from 1894 topographic map. (have fun examining this historic map for other stories this map tells!)

We all live in a watershed !
Now that we have discovered that landforms (topography) and gravity play a major role in defining a watershed or drainage basins it’s time to discover that no matter where you live, play or go to school, you are in a watershed

Looking at Sub-watersheds in Philadelphia

Philadelphia has many sub-watersheds (or drainage basins) within the city boundaries. A drainage basin is like a sink, that collects and drains water from its highest spot to its lowest point, where it collects or flows with water. (like a pond, creek or stream).

Our Philadelphia watershed is a sub-watershed of the larger watershed and our river or creek (or sewer pipe) is a tributary of the larger river downstream. Keep following the water until the ocean is reached. The ocean marks the last portion of the watershed address. For example, if we live in the Wissahickon Watershed, our watershed address could be written as Wissahickon, Schuylkill, Delaware, Delaware Bay, Atlantic Ocean.

Use the following “ nested “ watersheds maps to discover that we all live in a Watershed
We All Live in A Watershed: Neighboring Counties Watershed Map
We All Live in A Watershed: Schuylkill River Watershed Map
We All Live in A Watershed: Delaware River Watershed Map

Check out this resource to follow a drop of rain through a watershed!
River Runner is an interactive resource that lets users trace the path of a drop of rain, from where it first falls to the ground, to the body of water where it ends up. The resource utilizes data from the United States Geological Survey to map watersheds and get accurate topographies of mountains as well.

Extension

USE MATH TO GRAPH RAINFALL AMOUNTS OVER TIME

Use Philadelphia’s monthly precipitation averages in order to find the average rainfall and create graphs to describe the data distribution and what it represents.

Add other cities in the US and other countries to contrast data from areas that are in a drought or experience heavy rainy seasons (or even variations within a state such as east and west Texas).

SOCIAL STUDIES: TOPOGRAPHIC COMPARISON BETWEEN PENNSYLVANIA AND ANOTHER STATE

Students examine the Topographical Map of Pennsylvania.

Teacher Support

Essential Question: What is the Value of Water?

Guiding Questions:

Engage

What evidence of the components of the water cycle can you see?

Explore and Explain- Part 1

What forces drive the water cycle?

Explore and Explain– Part 2

What is a watershed?
What is the interaction between the natural water cycle and the watershed and how does the natural water cycle and the watershed interact?
What is a topographic map? What do they reveal about watersheds?

Students will be able to:

Explore and Explain – 1

Review the basic four components of the water cycle.
Describe how water changes from one state to the other.

Illustrate how the 8 components of the water cycle interact with one another over time. Include the driving forces behind each component of the water cycle.

Explore and Explain – 2
Observe how topography and gravity affect the flow of water.
Identify the 7 sub watersheds of Philadelphia.
Identify the 6 major watersheds in PA.

Engage Activity:

On a sunny day, containers of water to pour on the ground.
On a rainy day, umbrellas and/or rain gear.
Student Watershed Observation tool

Explore & Explain Activity:

PART 1: WATER CYCLE
Clear Water Bottles (one per group)
Water
Sunny Window
Writing and Art supplies – markers, crayons, paper, pencils
Informational Text (see resources for suggestions)
RAN (KWL) template
Watershed Vocabulary Review

PART 2: THE WATER CYCLE AND THE WATERSHED
WATERSHED:

Blue and Black Washable markers
Freezer paper and/or aluminum foil
Spray water bottle
Paper towels
Watershed Vocabulary Review

TOPOGRAPHY:​
Dental floss
Soft modeling clay
Topographical Plan of Roxborough Reservoir, Philadelphia January 1894
Find Your Watershed (PWD Web locator)
Topographic maps (Philadelphia, Pennsylvania)
We All Live in A Watershed: Philadelphia Sub-Watershed Map
We All Live in A Watershed: Neighboring Counties Watershed Map
We All Live in A Watershed: Schuylkill River Watershed Map
We All Live in A Watershed: Delaware River Watershed Map
If students are making a 3-d model of a watershed, encourage them to use recycled materials and be creative

BASIC WORDS: COMPONENT PARTS OF THE NATURAL WATER CYCLE
Condensation (noun)
The part of the water cycle in which a vapor or gas is converted to a liquid
Evaporation (noun)
The process by which liquid changes into vapor.
Infiltration (noun)
The part of the water cycle in which water passes through (a substance) by filtering or permeating or penetrating its pores.
Percolation (noun)
The part of the natural water cycle in which water moves slowly downward through the porous ground
Precipitation (noun)
The part of the natural water cycle in which rain, snow, sleet, or hail falls from the atmosphere to the ground.
Recharge (verb)
The replenishment of an aquifer by the absorption of water.
Stormwater Runoff (noun)
The part of the water cycle in which water flows off the land into the nearest body of water
Transpiration (noun)
The part of the water cycle in which water is absorbed by living things, like plants and trees and evaporates into the atmosphere
Watershed (noun)
The region or area of land that drains into the nearest river or stream or other body of water.
ADVANCED WORDS
Aquifer (noun)
A body of permeable rock that can contain or transmit groundwater.
Contour Line (noun)
A line on a map joining points of equal height above or below sea level.
Gravity (noun)
The force that attracts a body toward the center of the earth, or toward any other physical body having mass.
Groundwater (noun)
Water held underground in the soil or in pores and crevices in rock.
Hydrology (noun)
A science dealing with the properties, distribution, and circulation of water on and below the earth’s surface and in the atmosphere.
Surface Water (noun)
Water that collects on the surface of the ground.
Topography (noun)
The study of elevation, or the peaks and valleys of a landscape, and how they affect the flow of water
Tributary (noun)
A river or stream flowing into a larger river or lake.

  • In their journals, students will describe how water changes from one state to the other and why that is important to understand.
  • After each stage of the natural water cycle is explained students can use index cards to write a description of the stage on one side and to illustrate the stage on the other side.
  • Recall the definition of a watershed. Identify the six major watersheds in PA, find three interesting facts about them and explain why it is important to do so. Identify the seven sub-watersheds of Philadelphia and trace the outline of the watershed in which you live on a map. 
  • Label the components of a watershed. Illustrate how topography and gravity affect the flow of water.

PA STEELS
Environmental Literacy & Sustainability
3.4.6-8.C Agricultural and Environmental Systems and Resources : Develop a model to describe how watersheds and wetlands function as systems, including the roles and functions they serve.
3.4.6-8.D Environmental Literacy Skills : Gather, read, and synthesize information from multiple sources to investigate how Pennsylvania environmental issues affect Pennsylvania’s human and natural systems.
Related Standards
NGSS
MS-ESS2-4 Earth Systems: Develop a model to describe the cycling of water through Earth’s systems driven by energy from the sun and the force of gravity.
ELA
W.6.2 Introduce a topic; organize ideas, concepts, and information, using strategies such as definition, classification, comparison/contrast, and cause/effect; include formatting (e.g., headings), graphics (e.g., charts, tables), and multimedia when useful to aiding comprehension.
Education for Sustainability
EfS F.e  Natural Laws and Ecological Principles – Make a case for why global citizens should understand the basic laws and principles derived from nature (materials cycles).
EfS I.1  Strong Sense of Place – Draw the parameters of their bioregion (watershed) , identify and list the characteristics of that bioregion, and make a case for why it is important to do so.
EfS C.8  The Dynamics of Systems and Change – See patterns over time and go beyond them to define structures within systems

Student Materials

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