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.
slope 10.0 m/kmknick 0 kmeroding 0 kmdepositing 0 km0.0 kyr
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?