How Rivers Carve Valleys

Geography · Physical Geography · ages 11-13

Name ______________________ Date ____________

Which water erodes more?
- Slow still water
- Fast moving water
- Frozen solid water
What three things does a river do with rock and soil?
- Erode, transport and deposit
- Freeze, melt and refreeze it
- Dig, bury and forget it
Fast water carries bigger loads than slow water.
Circle one: True False
A fall drops over hard rock with soft rock below. What happens next?
- The fall freezes forever
- The soft rock wears and the fall steps back
- The river flows uphill
Where do you find the deepest water on a river bend?
- The shallow inside edge
- The middle of a lake
- The fast outside bank
Upstream valleys are narrow and V shaped because the river cuts down.
Circle one: True False
A town plants cover crops and builds terraces above a muddy stream. What are they fighting?
- Erosion stripping the soil away
- Too many fish in the stream
- Clouds blocking the sun
A bend grows more curved each year. Why does the curve feed itself?
- Fish push the banks outward
- Rain falls only on bends
- Fast outside cuts while slow inside builds

Answer key

For grown-ups. Fold this page away before handing over the rest.

Fast moving water · Speed gives water the force to tear rock away.
Erode, transport and deposit · Wear it, carry it, drop it: those are the three river jobs.
True · Speed holds heavy stones up, and slowing drops them.
The soft rock wears and the fall steps back · The soft layer goes first, the lip collapses, and the fall retreats.
The fast outside bank · The fast outside current cuts into the bank and digs deep.
True · Young rivers saw downward before they swing sideways.
Erosion stripping the soil away · Cover and terraces slow runoff and hold the soil in place.
Fast outside cuts while slow inside builds · Cutting outside and building inside shove the bend further round.