Where did the change begin?
Labs / Geography
River Long Profile
A river never stops rearranging its own bed. It cuts down through steep headwaters, drops its load across the gentle lower reaches, and slowly bends toward a smooth concave curve graded to base level. Nudge the uplift, rock hardness and sea level, or drag across the land to shove up a barrier & watch the river wear it away.
Labs / Geography / River Long Profile
River Long Profile
A river never stops rearranging its own bed. It cuts down through steep headwaters, drops its load across the gentle lower reaches, and slowly bends toward a smooth concave curve graded to base level. Nudge the uplift, rock hardness and sea level, or drag across the land to shove up a barrier & watch the river wear it away.
Why it matters
Why explore this?
Geography explains how places, people, and Earth systems affect one another. This model lets you change one factor and watch its effects spread across space.
Explore
Try the model
slope 10.0 m/kmknick 0 kmeroding 0 kmdepositing 0 km0.0 kyr
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Where along the river is the bed being cut down, and where is sediment piling up? What sets the boundary between them?
- Crank rock hardness up. Why does a stubborn band of rock leave a step & a waterfall in the profile instead of a smooth curve?
- Raise the uplift rate. Does the land win the race and grow taller, or can the river keep pace and hold its graded shape?
- Push sea level up. What happens to the deposition zone near the mouth when base level rises to meet the river?
- Drag to build a dam across the channel. How long does the river take to saw back through it and return to grade?
Explain
Make sense of what happened
Connect the pattern to place: identify where the change begins, where its effects appear, and which process links those locations.
Check
Before you leave
What spatial pattern appeared?
Which process connects the cause and effect?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.