Dig Earth Studio Lab
River
Meander Lab.
Give a river room to wander. Adjust water flow, bank strength, sediment and vegetation, then watch erosion and deposition reshape the floodplain.
Follow a moving river.
Be the river scientist. Look for changing bends, sandy point bars and the moment an oxbow lake forms.
- 01Choose your river conditions.
- 02Run time and watch the river migrate.
- 03Save a result and compare the evidence.
Science tip: Change one setting at a time, then compare rivers after the same number of model steps.
Compare with step 0: the dashed gray line shows the original channel course. The colored areas are simplified process zones, not measured rates.
Before & after.
Compare step 0 with the current channel. Distances are displayed in illustrative metres (m) using a fixed 1 km-wide map. A model step is not a real-world year.
| Measurement | Before | After | Change |
|---|---|---|---|
| River sinuosity ratio | — | — | — |
| Channel length m | — | — | — |
| Mean channel displacement m | — | — | — |
| Oxbow cutoffs count | — | — | — |
| Mean channel width m | — | — | — |
Run A vs Run B.
Run an experiment and select Save result as A. Then reset, change one condition and run again. Results from A will be kept while B evolves. Pause or save A at a chosen model step, then compare B at the same step.
| Measurement | Saved A | Current B | B − A |
|---|---|---|---|
| River sinuosity ratio | — | — | — |
| Channel length m | — | — | — |
| Mean channel displacement m | — | — | — |
| Oxbow cutoffs count | — | — | — |
| Mean channel width m | — | — | — |
Can a river change its own course?
Run the same river under different conditions and look for patterns. Outer bends commonly erode while inner bends accumulate sediment. Vegetation can stabilize banks and reduce migration. Continued bend migration may create an oxbow cutoff.
Model note: This is a conceptual river-evolution model, not a calibrated hydraulic simulation. The map represents an illustrative 1,000 m × 600 m floodplain with a 100 m scale bar. Channel length, mean width and displacement are expressed in illustrative metres (m), not measurements of a real river. Sinuosity is channel length divided by the straight-line end-to-end distance. Displacement is the mean shortest distance to the starting channel centerline. Model steps describe simulated updates, not years. Erosion and deposition colors indicate potential processes, not measured rates. This simulation must not be used for river engineering or flood prediction. A separate classroom activity pack is planned.
Why do rivers meander?
Rivers flowing across floodplains often develop bends that migrate over time. Erosion can remove material from the outside of a bend, while sediment accumulates on the inside. Together, these processes reshape the channel and surrounding landscape.
Outer-bend erosion
Flow can undercut the outside of a river bend, creating a cut bank. Bank material and plant roots influence how quickly that bank changes.
Inner-bend deposition
Sand and other sediment can settle along the inside of bends, building curved point bars. Sediment supply influences their growth.
Oxbow lake formation
A growing bend can become so tight that the river takes a shorter route through its neck. The abandoned loop may form an oxbow lake.
Try changing just one setting between runs and compare the river at the same model step. The scientific process view identifies likely erosion and deposition zones; it does not calculate measured rates.