Home Geography for Primary Grades · Lesson XIX · Unit 5: Rivers
19. More about rivers: watersheds, rapids, waterfalls and bends
Goal: Your child follows a river from source to sea and explains tributaries, a water-parting (watershed), rapids, waterfalls, and why rivers wind on flat land.
You'll need
- The sand tray with damp sand and a watering can, or a sloping patch of dirt and a hose
- A piece of folded cardboard (to show a roof)
- Small stones
- A geography notebook (any notebook kept just for these lessons) and a pencil
What's in the book
An imagined journey down a river: the rill at its source, tributaries (branches), the water-parting or water-shed shown by rain on a roof, rapids, a waterfall (the Falls of Niagara), and the slow, wide, winding river on the level land below. Questions ask why rivers are swift in some places and slow in others, and why they wind.
The lesson, step by step
Follow the river
SayToday we will pretend to follow a river all the way to the sea.
Read the start of the journey. Ask: What is a stream that feeds another stream called?
The word is tributary.
The roof
Fold a piece of cardboard like a roof and drip water on the ridge. Watch it split: some runs down one side, some down the other.
Now, hills, like the roof of a house, send off streams on both sides.
SayA hill or ridge that sends water two ways is called a water-parting or watershed.
Rapids
Read about rapids. In the sand tray make a steep part and put small stones in the channel. Pour water and watch it rush and splash.
Ask: Why are they called rapids? (The water runs rapidly, fast.)
Waterfalls
Read about the waterfall.
When the water of a river falls over high rocks, it is called a waterfall or cataract.
What we know now: the book calls Niagara Falls the greatest waterfall in the world. It is one of the most famous and carries a huge amount of water, but many waterfalls are taller; the tallest is Angel Falls in Venezuela.
Wide and winding
Make a long, gentle, nearly flat slope in the tray and pour water slowly. Watch it wander.
Ask the book's questions: Why is the river swift in some places and slow in others? Why is it crooked and winding on level land?
Tell the journey
Your child tells the whole river journey back, in order: spring and rill, tributaries joining, rapids, waterfall, slow winding river, the sea.
Afterwards
On a free online map, find Niagara Falls between the United States and Canada, and look at a river near you to see where it winds most.
Answers to the book's problems
A stream that feeds another stream is a tributary (or branch). A ridge or hill that sends water down both sides is a water-parting or watershed. Rapids are called so because the water rushes rapidly down a steep slope among rocks. A river is swift where its bed is steep and slow where the land is nearly level. It winds on level land because the slow water is easily turned aside, while on a steep hillside it runs fast and is not easily turned.
Worked out for this site from the scan. If a number in your copy differs, trust the book.