Cabernet2D

Confluence/Bifurcation Flow Analysis

Supports unlimited tributaries and distributaries. Discharge or water level boundary conditions can be set at all upstream tributaries, and water level boundary conditions at all downstream distributaries.

Flow velocity distribution, water level/bed longitudinal profile, and discharge hydrograph at the Chikugo-Katsura River confluence. Data: Yasuda, Shirakawa & Kamoshida (2025)

Complex River Network Computation

Using unstructured grids, it can compute complex river networks with multiple confluences and bifurcations as a unified model. Supports display of discharge and sediment transport at arbitrary cross-sections. A versatile grid generation tool simplifies mesh creation.

Computation of a river network with four rivers (River #1-#4) with confluences and bifurcations. Discharge displayed at arbitrary cross-sections

Bed Deformation & Vegetation Dynamics

Computes sediment deposition and bed deformation at confluences. A vegetation lifecycle model (germination, growth, resistance, washout) is integrated within the bed deformation loop, enabling reproduction of long-term processes: sandbar formation, tree germination, forest belt formation, and sandbar stabilization.

Bed deformation contour and velocity vectors at the Sorachi-Furano River confluence

Sediment deposition at confluence leading to sandbar development, land formation, and tree growth

Bifurcation Point Computation

Supports bifurcation point computation that was not possible with Nays2DH. Both main channel and distributary start from dry conditions, with flow distribution determined automatically by the model. Bifurcation with bed deformation can reproduce decreasing distributary discharge due to sediment deposition.

Bifurcation point computation. Both channels start from dry conditions with automatic flow distribution. Data: Minami & Yoshitake (2024)

Levee Breach Simulation

Supports levee breach simulation with linked display of 3D bed topography, water surface, and 2D flow patterns. Accuracy verified through comparison with experimental results.

Reproduction of the Chiyoda experimental flume large-scale breach experiment. Top: experimental results (topography), Bottom: computation results (topography and depth). Data: CERI, Shimada et al. (2012)

Edge Obstacles & Groins

Edge-based obstacle specification enables representation of infinitely thin groins (permeable and impermeable). Supports display of permeability and vorticity distribution, and can compute sandbar control by groins and sediment deposition/tree growth between groins.

Velocity vectors and permeability/vorticity distribution for edge-based groin obstacles

GELATO (Lagrangian Particle Transport Model)

Includes the built-in GELATO model that places neutral particles on bottom and surface flows for Lagrangian particle transport simulation. Useful for flow visualization.

Riemann Invariant Boundary Conditions

Using Riemann invariants for upstream/downstream boundary conditions provides higher accuracy than Manning's equation. Verified with the Ishikari River 1/50 scale model experiment, confirming computed discharge closely matches experimental discharge.

Boundary conditions using Riemann invariants. Computed discharge (0.25 L/s) closely matches experimental discharge (0.24 L/s). Kato, Shimizu & Imamura (2025)

Floodplain Structures

Supports flow simulation with hydraulic structures including culverts, sluice gates, drainage pumps, and gates installed on floodplains.