Features
Rivers: Exploring moving water with children
Henry and Hannah, 4-year-olds in Ms. Tate’s class, are on the playground with shovels and buckets of water.
“Let’s build a river,” Henry challenges.
“Rivers are water,” replies Hannah, emptying her bucket with a splash.
“No, no, no, rivers are long and twisty,” protests Henry. “Remember the picture of the Hudson River in the art room? We need to make the river stay in a line.”
The two look to Ms. Tate for help.
Before the United States had a name, explorers navigated North American rivers observing and recording information about the watery worlds that later shaped U.S. cities, agriculture, commerce, recreation, and family life. Today, we—and the children we teach—hear the news when rivers flood cities and fields and when drought dries lake beds and streams. We all respond to the alarms about water shortages and restrictions and struggle with the cycles of too much and too little rain. The connection between U.S. social history, geography, and the climate is water—especially the fresh moving water that fills creeks, streams, and rivers.
In communities throughout the United States, rivers supply drinking water, irrigate crops, power cities, support wildlife, and offer recreational and commercial activities. Streams, wetlands, and aquifers are equally important, providing a key role in supporting commerce and ecological well-being for all plant and animal life.
A little science background
But what is a river? Geologists—earth scientists—describe a river as a stream of water that flows in a bed and empties into another body of water. This moving stream can flow into an ocean, a lake or pond, or another river. And where does a river begin? Scientists describe the water cycle—an endless rotation of precipitation, evaporation, and condensation. Precipitation—rain, hail, sleet, or snow—falls to the earth from clouds. Some precipitation falls to the ground into existing bodies of water; some falls onto land and is absorbed or diverted into runoff. The sun heats the bodies of water and it evaporates, turning the water into vapor that rises into the air. As the vapor rises, it cools, eventually becoming water droplets called condensation that become so heavy they fall to the ground again.
Precipitation can also be absorbed into the soil to sustain vegetation. After the moisture is distributed through the plant, some of the water passes out of the plant leaves and evaporates in the air. This process is called transpiration.
The headwaters or source of a river is its starting place. This may be a lake or spring; it could be at the confluence of several small rivers or tributaries creating a big one. Usually rain and melting snow at higher elevations (like a mountaintop) run downhill using the force of gravity. This water may be contained in a geological bowl like a lake or pond.
If the water continues to flow—as when a lake has too much water to contain it—the ribbon of water will continue to make its way to the next large body of water. The Mississippi River, for example, has its headwaters in Itasca State Park in northern Minnesota. There the river is about 3 feet deep. It flows south through 13 states to its mouth or drainage point at the Gulf of Mexico south of New Orleans. At New Orleans the river is about 200 feet deep. A raindrop that falls in the Itasca headwaters takes about 90 days to reach the Gulf of Mexico.
The moving water in a river, stream, and even a creek can erode terrain and fill the water with rock, soil, sand, and runoff debris like garbage as well as chemicals and minerals in the soil. Water erosion has formed many of the deep canyons of the western United States and the more gentle valleys to the east.
Sometimes too much rain or snow melt can supersaturate the land—the water can’t be absorbed by the soil or flow into a contained river system quickly enough. Usually this simply results in muddy shoes or slosh. Sometimes, however, major flooding can occur, causing damage to homes, businesses, livestock, and families. Communities along major waterways usually prepare for spring thaw flooding by fortifying levees—earthen barriers—and building spillways or temporary reservoirs for the excess water.
A watershed is an area of land that water flows through, under, or across. Watersheds feed rivers. Some watershed areas are ridged—the water trickles downhill to a common body of water in rivulets or small streams. A watershed can also be flat—the water seeps into lakes, ponds, and swamps or into underground aquifers.
As the U.S. population grows and cities develop, the need for water increases. Often this means that dams are constructed to contain water in reservoirs and lakes for use in agriculture, industry, and recreation.
Activities for children
Use the following activities to introduce children to basic water concepts and qualities. Employ the scientific method—asking questions, forming hypotheses or guesses, manipulating details, and drawing conclusions for each activity.
Investigating the water cycle
Here’s what you need:
electric kettle
aluminum foil
4-inch square of cardboard
tongs
glass container
ice cubes
submersible thermometer
paper and pencil for dictation
1. Plan this activity for small groups of children to provide easy opportunity for questions and observations. Remember to review safety rules so that children can be actively involved without risk of injury.
2. Gather all materials in an area with an available electrical outlet.
3. Fill the kettle with water and turn it on. While it’s coming to a boil, show the children how to fold pieces of foil over the squares of cardboard. Let them practice holding the cardboard squares with tongs.
4. Pour tap water into a glass container and ask the children to hold their foil-covered cardboard over the container. Ask what they observe and document their observations.
5. When the water boils, allow each child to use tongs to hold a cardboard square in the steam. Talk with the children about what they see (small drops of water on the foil). Determine what they understand about evaporation and condensation. What happens when the cardboard is moved away from the steam? What happens to the drops of water?
6. Continue the experiment by pouring tap water into a glass container. What happens? Is the outside of the glass dry or wet? Measure and document the temperature of the water.
7. Observe the different qualities of condensation when you add ice cubes to the glass of water. What happens on the side of the glass? What drips to the table? Ask the children to describe—and then measure—the temperature of water with ice.
8. Document hypotheses—guesses—about why condensation forms on surfaces when the inside and outside temperatures differ.
Mapping rivers
Here’s what you need:
large U.S. map
laminator or clear, adhesive-backed plastic
erasable markers
1. Introduce children to a map of the United States. Talk with them about how maps guide travelers, show geological features like mountain ranges and coastlines, identify population centers by size, indicate political districts like state and county boundaries, and display highways.
2. Encourage the children to investigate the map and discover its features. Be prepared to answer questions, to talk about directions like north and south, and to describe distances.
3. When children are familiar with the map’s features, introduce the two large mountain ranges in the United States (the Rocky Mountains in the West and the Appalachian Mountains in the East).
4. Encourage the children to identify rivers and to trace their routes with markers. Which are the longest rivers? How many states do they run through? Where is the mouth? Where are the headwaters?
5. Challenge the children to identify smaller rivers and tributaries. How many can they find?
What are you digging for?
Here’s what you need:
small shovels or garden spades
open grassy area
heavy plastic sheeting
bucket of water
1. Introduce the activity by asking children what they think they will find under the grass. Encourage conversations about rocks, soil, insects, and worms, for example. Ask if they think they can dig deep enough to find water.
2. Mark an area about 12 inches square on the ground. Cut a sheet of plastic about 36 inches square and spread it on the ground near the designated digging area. You may need to weigh it down with stones.
3. Invite the children to take turns digging, indicating that this activity will take several days to complete. As shovels full of dirt come out of the hole, help children place the dirt on the plastic sheet. Encourage an investigation of the soil. Is it filled with loose sand or gravel—porous soil? Or is the soil tightly packed clay or even solid rock?
4. Invite children to pour a few cups of water into the hole at the end of each digging day. Porous soil will drain quickly; clay soil will hold the water longer because there are fewer pockets for the water to drain into. Consider timing and charting the drainage time as the hole gets deeper.
5. Cover the hole at the end of each day with the second sheet of plastic.
6. Depending on the strength and interests of the children let them continue with the dig. Often soil will be damp at about two feet—they’ve dug for water.
Explore erosion and water flow
Here’s what you need:
large sheet of plastic or canvas
stones
soil
bucket of water
ladle
1. In preparation, spread the plastic or canvas on an area of flat ground. Introduce the activity by talking about mountains and water flow.
2. Invite children to stack stones—large and small—in a pile.
3. Dampen the soil, both porous and clay. Pack the soil around the stones into a mountain shape. Encourage creativity with peaks, valleys, boulders, and even vegetation. Pack additional soil at the base of the mountain.
4. Using the ladle, slowly pour water onto the top of the mountain. After each ladleful, encourage children to observe and describe the paths or channels the water carves into the soil of the mountain side. Watch for tributaries—side channels—and how the main channel widens as more water falls. Notice how some of the stones and soil flow into the channel with the water. Talk with the children about the fan-shape the water takes at the base of the mountain.
5. Challenge the children to build a system for containing or directing the water. How can they move the water from the mountaintop to an area that needs water, like a vegetable bed?
Sediment, silt, and algae
Here’s what you need:
2-liter, clear-sided plastic bottles with lids
spoons
yard dirt and gravel
rocks
green and brown leaves
paper and pencil for dictation
1. Introduce this activity with conversations about weight, water clarity, and the impact of sunlight on still water.
2. Fill the bottles about two-thirds full with tap water.
3. Invite children to use a spoon to add a combination of dirt, gravel, sand, and stones to the bottle.
4. Encourage observation. What happens to the water when materials are added? Does it stay clear, or is it muddy?
5. Cap the bottle and shake. What happens now? What sinks to the bottom first? Why?
6. Add a few leaves—green and brown—to the bottle. What happens?
7. Place some bottles in a sunny window and others in a dark cabinet. Compare the bottles daily for two weeks. What happens? Help children form hypotheses about algae growth and sunlight.
Changing ecosystems
Here’s what you need:
two glass bowls
two freshwater aquatic plants
chlorine-free water such as bottled spring water or rainwater
measuring spoons
salt
paper and pencil for dictation
1. Introduce this experiment by talking with children about healthy and unhealthy environments. Ask how they think they would feel if the water fountain offered salty water instead of fresh water?
2. Fill the two bowls with spring water. Alternatively, fill the bowls with tap water, and allow the bowls to stand overnight so that the chlorine dissipates.
3. Place a plant in each bowl. Document children’s observations.
4. Add 3 teaspoons of salt to one bowl. Observe and compare the two bowls daily, and record children’s observations.
5. After two days, add 3 additional teaspoons of salt to the bowl with salted water. Continue to observe and compare.
6. How many days pass before the children notice changes in the plant with the salted water? What do they see? What do they observe in the bowl without salt?
7. Help the children form hypotheses about the impact of changes in the ecosystem of the bowl.
Note: You can buy freshwater aquatic plants from a plant nursery or aquarium supply store. You might also collect plants from a farm pond.
Collecting rainwater
Typically we take the availability of water for granted. Indoors, we turn on a faucet to wash hands, shower, wash clothes, and brush teeth. Outdoors, we wash pets and cars, and direct water to gardens and trees. Recognizing, however, our reliance on the water cycle for these activities, we quickly understand that no rain—drought conditions—will limit the availability of water for everyday tasks.
Two activities can make this understanding concrete for children. The first is to simply set up a rain gauge. Buy a commercial gauge or use a clear plastic jar. Use a permanent marker and ruler to indicate inches on the outside of the jar and place it in an open area of the playground. Encourage the children to check the gauge regularly and to chart rain accumulations.
On a larger scale, secure a barrel for rainwater harvesting. Often municipalities offer these at low or no cost. Or you can seek donations from community groups or families; the cost of a 50-gallon barrel is usually less than $100.
Prepare a sturdy platform for the barrel and, if possible, position it close to a building under a gutter downspout. Make sure to screen the top so mosquitoes don’t have a breeding place. Use the collected rainwater for gardens and always talk with children about conservation. What will happen when the barrel is empty?
River facts
Of all of the water on Earth, little is fresh water suitable for drinking. The ratio is about the same as 1 tablespoon in a gallon of water.
Most of the world’s major cities are located near the banks of rivers.
About 1.2 billion people live without access to clean water.
The longest river in the world is the Nile in northeastern Africa. It is about 4,132 miles in length. The second longest is the Amazon in South America at about 4,000 miles in length.
The longest river in the United States is the Missouri River, stretching to 2,340 miles. Combined with the Mississippi, it forms the longest North American river at about 3,902 miles.
In the United States there are about 3.5 million miles of river, stream, and creek.
It takes about 1,800 gallons of water to manufacture a pair of jeans.
Upriver refers to the direction of the river’s headwaters; downstream refers to the direction in which the river flows—toward its mouth.
In the United States 6.8 billion gallons of water are flushed in toilets every day.
Resource books for children
Arnosky, Jim. 2008. The Brook Book: Exploring the Smallest Streams. New York: Dutton Children’s Books.
Beatty, Richard. 2011. Rivers, Lakes, Streams, and Ponds. Chicago: Raintree.
Cherry, Lynne. 2002. A River Ran Wild. New York: HMH Books for Young Readers.
Hiscock, Bruce. 1997. The Big Rivers: The Missouri, the Mississippi, and the Ohio. New York: Atheneum Books for Young Readers.
Paulsen, Gary. 2001. Canoe Days. New York: Dragonfly Books.
Telford, Carol and Rod Theodorou. 1998. Down a River. Des Plaines, Ill.: Heinemann.
Williams, Vera B. 1981. Three Days on a River in a Red Canoe. New York: Mulberry Books.
Yolen, Jane and Barbara Cooney. 1995. Letting Swift River Go. Boston: Little, Brown Books for Young Readers.
References
Environmental Protection Agency. Kid’s Stuff. http://water.epa.gov/learn/kids/waterkids/kids.cfm.
National Geographic. River Explorer. http://kids.nationalgeographic.com.
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