Exercise: the gravel-river long profile

This model evolves a single-segment gravel river through time. Press ▶ Run, then drag the sliders while the simulation runs and watch the long profile respond:

• Water discharge $Q$ – more water lowers the equilibrium slope, giving a gentler profile.
• Bed-load sediment input $Q_s$ – more sediment steepens it.
• Base level – raising or lowering the downstream boundary aggrades or incises the profile.

These are the three controls of Lane’s balance, played out dynamically. Use Set to equilibrium to jump to the steady state for the current settings.

What to do

(To be written.)

The first load takes 10–30 seconds while your browser downloads the Python runtime – about 60 MB. It runs smoothly after that, and the download is cached, so returning to the page is fast. Nothing is sent to a server: the model runs on your own machine, inside the browser tab.

Under the hood

The model is GRLP, which solves for the long profile of a gravel-bed river under a threshold-channel assumption (Wickert & Schildgen, 2019). It is compiled to WebAssembly with artesian and runs via Pyodide.