Greetings Dr. Jirka,
I am a new user of Hydrus-1d and I have to simulate groundwater flow and contaminant transport using the equilibrium model and then the mobile-immobile or dual-porosity model for a total length of 1400 minutes, from an in-situ experiment at 350 m depth. My initial and boundary conditions are as follows: Dirichlet (inflow), zero-gradient (outflow); constant concentration at inflow point for initial specific period and zero after the period (pulsive). My questions are:
- do I have to select time-variable conditions to specify that I have an input concentration for the first 4.5 minutes and then 0?
- do I have to select in the water flow boundary conditions window for the upper boundary condition ''Constant Pressure head'' and for the lower boundary condition ''Free Drainage''?
- regarding the boundary conditions for solute transport, do I have to select for the upper boundary condition ''Concentration BC'', and for the lower boundary condition ''Zero Concentration Gradient''?
- and then, in the graphic area what do I have to do more regarding the initial and boundary conditions?
Thank you in advance!