Input (pre-processing) › Solute transport

Solute transport: boundary conditions

The page corresponds to the Solute Transport Boundary Conditions dialog of HYDRUS-1D. The equations are in solute transport.

Upper boundary

Condition	Description
Concentration BC	first type: the concentration of the top node is prescribed
Concentration flux BC	third type: the solute flux equals the water flux times the concentration of the entering water; recommended for the soil surface (no solute enters with evaporation)
Volatilization	concentration flux plus gas diffusion through a stagnant boundary layer of thickness dSurf to the atmosphere with the concentration cAtm Jury et al. (1983)

Lower boundary

Condition	Description
Concentration BC	first type
Concentration flux BC	third type
Zero gradient	∂c/∂z = 0: solute leaves the profile by advection only (deep profiles, free drainage)

Concentrations

c top and c bottom per solute [M/L³]; with time-variable or atmospheric boundary conditions the concentrations come from the cTop and cBot columns of the time-variable data. Pulse duration: after this time [T] the boundary concentrations are set to 0 – only without an atmospheric boundary condition.

Literature cited in this topic

Jury, W. A., W. F. Spencer, and W. J. Farmer (1983). Behavior assessment model for trace organics in soil: I. Model description. Journal of Environmental Quality 12(4): 558–564. doi:10.2134/jeq1983.00472425001200040025x

All sources: References.