PC-Progress Discussion Forums

I suggest that you review the literature on how different people presented the results of their sensitivity analysis, e.g., Šimůnek, J., O. Wendroth, and M. Th. van Genuchten, Parameter estimation analysis of the evaporation method for determining soil hydraulic properties, Soil Science Society of A...

In the Solute Transport dialog window, you selected simultaneously both the Isotope BC checkbox and the PFAS module. I do not know how you managed to do that since the GUI should automatically prevent you from doing it (i.e., it automatically disables Isotope BC when PFAS is selected). Anyway, you n...

The problem is likely with the spatial discretization. Note that when the program fails, the moisture front reaches the elements that have the size of 1.5 m. You should read the FAQ 3 (Notes on Spatial and Temporal Discretization - https://www.pc-progress.com/en/Default.aspx?h3d-faq-01-10#k3). Note ...

The standard version of HYDRUS-1D allows only a single root system in the soil profile. It does not allow two overlapping root systems (e.g., forest and pasture, that would compete for water and nutrients). I do have my own internal version that can do something like that (see, e.g., Li et al., 2017...

The clogging option was not available to the public until it was implemented into Version 5.04 of HYDRUS into a standard 2D computational module. clogging.png There are multiple clogging models (e.g., exponential, linear, parabolic, with or without a time lag, etc) implemented describing a time redu...

This project has clearly not been created in Version 5 of HYDRUS, as you have indicated by using this forum. J.

I do not have any other advise without seeing the project. J.

Yes it is possible. You should follow the following steps: 1. Finish calculations for the first project (e.g., P1) 2. Save the P1 project. 3. Make a copy of the P1 project using the Project Manager (or the command Save As) to create a new project (e.g., P2). 4. Open project P2 and make any modificat...

I would suspect that the numerical problems stem from very low values of n, rather than differences in the Ks values between different layers. Note that we recommend (see FAQ 26, https://www.pc-progress.com/en/Default.aspx?h3d-faq-21-30#k6) to consider the VGM model with an air-entry value of – 2 cm...

Average recharge: Visually it seems so. However, it would be better to take cumulative bottom flux and divide it by time to get the average recharge rate. Solute BC. Solute fluxes as positive for inflow and negative for outflow. I do not know why you don’t find this information in the manual or help...

Hydrus calculates bottom water fluxes (usually referred to as recharge) for any specified boundary conditions. For a free drainage BC, the bottom flux is always downward (i.e., negative). For a pressure head BC, it can be both downward (i.e., negative) or upward (i.e., positive), depending on the co...

You use unrealistic (ridiculous) parameters. For example, you had the saturated water content for the third material equal to 6.8 (while it obviously must be smaller than 1). Also, you had a negative solid fraction for heat transport parameters. When I fixed these errors, the program seemed to run O...

I believe that your mass balance problems are caused by your set up. You have too many boundary condition records (175296) at a relatively short interval, which does not allow the code to select the optimal time step. The time step can not be larger than the interval between individual boundary cond...

Incorrect files were posted for the “Paper 1a” and “Paper 1b” examples. I have now posted the correct files. J.

Yes, under normal conditions (when you do not control what’s happening at the surface by the bottom BC), HYDRUS will take into account the ponding water layer when simulating infiltration. As long as there is a water layer at the surface, precipitation will be added to this water layer, and infiltra...