Monopile Scour — 2D Bed-Shear Field Map

The same Shields-threshold and Sumer-Fredsøe scour physics as the 3D monopile lab, rendered as a top-down bed-elevation grid instead of a 3D seabed mesh. An analytic 2D potential-flow solution around the pile computes a local current speed-up at every grid cell — fastest at the flanks, stalled at the fore-and-aft stagnation points — and each cell independently erodes toward its own local equilibrium depth, with the excavated sediment volume tracked and redeposited downstream as a mass-conserving mound. Adjust current speed, sediment grain size and simulation time acceleration, and toggle rock-armor scour protection, to watch the pit's genuinely 2D flank-weighted shape develop and reach equilibrium.