This is a streamwise x–height cross-section of the same canopy-flow physics as the 3D meadow patch, redrawn as a 2D-native field simulation instead of a camera view. Seagrass shoots act as a submerged canopy whose combined drag slows the water below the free-stream speed above it (Nepf, 1999):
a = n·d (frontal area per bed area, m⁻¹)
Uc / U0 = 1 / √(1 + Cd·a·h) (canopy attenuation)
Kz,canopy ≈ Kz,above · (Uc/U0) (turbulence suppressed in-canopy)
The left-margin arrow column plots U(y) directly — short arrows inside the canopy band, full-length above it — a profile diagram the 3D scene never rendered. Each particle advects horizontally at the local U(y) and falls under its Stokes settling velocity, perturbed by a turbulent random walk scaled by local Kz:
ws = 2r²(ρs − ρw)g / (9μ) (Stokes settling velocity)
Δy = (−ws + η·√(2·Kz·Δt))·Δt, η ~ N(0,1)
What's new here versus the 3D version: capture events are binned by their streamwise position into a 1D deposition-along-x field (the bars along the bed), directly revealing that most trapping happens near the upstream edge of the meadow where the canopy first interrupts the flow — an emergent spatial pattern the 3D model's single whole-bed carbon average couldn't show. A particle that reaches the bed while inside the meadow is captured into that bin; one that drifts past the downstream edge escapes untrapped. Denser, taller canopies quiet near-bed turbulence and raise residence time, which is the physical reason vegetated meadows bury far more organic carbon than bare sediment (Gacia & Duarte, 2001; Hendriks et al., 2008). Runs at ~40× real time.
- Shoot density / canopy height — set a and h, driving Uc/U0 and the arrow-profile shape.
- Free-stream current — sets U0, the speed above the canopy band.
- Particle diameter — sets the Stokes settling velocity ws (fine floc vs. coarser sediment).