Search found 4726 matches

by Jirka
Fri Aug 16, 2019 8:26 pm
Forum: Hydrus 1D
Topic: Integrating profile water content over depth
Replies: 16
Views: 13760

Re: Integrating profile water content over depth

The quotation that you give is related to the direct module (i.e., h1d_calc.exe), which indeed allows you to have up to 100 observation nodes. It is not related to the inverse module (i.e., h1d_clci.exe), which allows you to have up to 10 observation nodes. And you are using the inverse module. J.
by Jirka
Thu Aug 15, 2019 4:00 pm
Forum: Hydrus 1D
Topic: Run Hydrus-1D on Linux
Replies: 9
Views: 8304

Re: Run Hydrus-1D on Linux

I have never worked, and hopefully never will, withLinux, and thus cannot help.

You should first try to run the test examples that come with the HYDRUS-1D installation to see whether the problem is with your input or with your compiled program.

J.
by Jirka
Wed Aug 14, 2019 10:56 pm
Forum: Hydrus 1D
Topic: Solute transport as function of soil water content
Replies: 11
Views: 165

Re: Solute transport as function of soil water content

That's exactly what happens. There is no mass transfer if you have initially an equilibrium. Once water content increases, it dilutes concentration and mass transfer starts. J.
by Jirka
Wed Aug 14, 2019 6:17 pm
Forum: Hydrus 1D
Topic: Solute transport as function of soil water content
Replies: 11
Views: 165

Re: Solute transport as function of soil water content

No. The mass transfer is nonzero only when there is non-equilibrium, i.e., when the liquid phase is not in equilibrium with the solid phase (see eq. 3.9). When the soil is dry, there is only very little solute mass in the liquid phase (at equilibrium) and the mass transfer can start only once water ...
by Jirka
Wed Aug 14, 2019 3:39 pm
Forum: Hydrus 1D
Topic: Solute transport as function of soil water content
Replies: 11
Views: 165

Re: Solute transport as function of soil water content

Note that for non-equilibrium solute transport model, you need to specify the initial condition for the liquid phase concentration and for the kinetically sorbed concentration (concentration on Type-2 sites). While the former one is an equilibrium concentration and thus the equilibrium sorbed concen...
by Jirka
Wed Aug 14, 2019 3:35 pm
Forum: Hydrus 1D
Topic: Inverse Model Input
Replies: 1
Views: 10

Re: Inverse Model Input

1. Yes. For Type=0 (cumulative flux), position=1 for the upper boundary and =2 for the bottom boundary.
2. Yes, observation nodes are numbered sequentially, starting from the top.

Note that you could easily find the answers in the examples distributed with the HYDRUS-1D software.

J.
by Jirka
Mon Aug 12, 2019 2:06 pm
Forum: HYDRUS (2D/3D)
Topic: elongated mesh
Replies: 5
Views: 25

Re: elongated mesh

If you are new to HYDRUS, you should read about rules on spatial and temporal discretization (FAQ 8):
http://www.pc-progress.com/Documents/No ... zation.pdf

J.
by Jirka
Fri Aug 09, 2019 7:03 pm
Forum: Hydrus 1D
Topic: Recommended Compilers
Replies: 4
Views: 2503

Re: Recommended Compilers

Getdat and Gettime are compiler-specific functions, which should be replaced. The Function RTime() uses data provided by these two function. You can find it in the file Time.for. J.
by Jirka
Thu Aug 01, 2019 7:15 pm
Forum: Hydrus 1D
Topic: Root Depth defined in multiple parts of Hydrus
Replies: 1
Views: 31

Re: Root Depth defined in multiple parts of Hydrus

This seems to be something that should be quite clear from the simulated results, right?

If you select the option "Root Growth" in "Main Processes", then values calculated from "Root Growth Parameters" are used for rooting depth and values from the Meteo section are ignored.

J.
by Jirka
Mon Jul 29, 2019 9:24 pm
Forum: Hydrus 1D
Topic: Splitting actual ET into E & T
Replies: 3
Views: 596

Re: Splitting actual ET into E & T

Potential ET is usually evaluated using models such as Penman-Monteith, Hargreaves, etc, from measured meteo data. See references given in the HYDRUS-1D manual: Monteith, 1981; Monteith and Unsworth, 1990; FAO, 1990; Hargreaves, 1994; and Jensen et al., 1997.

J.
by Jirka
Sat Jul 20, 2019 11:00 am
Forum: Hydrus 1D
Topic: Root water uptake Kernza
Replies: 3
Views: 107

Re: Root water uptake Kernza

I do not think that what you write is exactly true. Note that crop coefficients are small during early crop growth (much lower than 1). I.e., the crop coefficient is taking into account the reduction of potential evaporation to actual values, which HYDRUS does using the hCritA value. J.
by Jirka
Sat Jul 20, 2019 10:55 am
Forum: Hydrus 1D
Topic: Guidance or your Opinion for an idea
Replies: 1
Views: 63

Re: Guidance or your Opinion for an idea

Ashkan, It should be technically possible to do what you described using HYDRUS-1D (i.e., using both temperature and moisture data in the objective function). However, the information content of such data (e.g., temperatures) for the estimation of soil hydraulic properties for a given experimental s...
by Jirka
Thu Jul 18, 2019 12:48 pm
Forum: Hydrus 1D
Topic: Boundary condition implementation in Hydrus-1D
Replies: 4
Views: 85

Re: Boundary condition implementation in Hydrus-1D

I think that the answer is obvious. The numerical model does not consider semi-infinite profile (as the analytical solution does); the soil profile is always finite and the boundary conditions are specified at a given locations and this BC affect the concentration profile in its near vicinity. If yo...
by Jirka
Thu Jul 18, 2019 8:57 am
Forum: Hydrus 1D
Topic: Boundary condition implementation in Hydrus-1D
Replies: 4
Views: 85

Re: Boundary condition implementation in Hydrus-1D

The solute transport part of HYDRUS-1D has been extensively and successfully tested against the analytical solutions from CFitm, CFitIm, and CXTFIT. Note that these analytical solutions are valid for different surface (Dirichlet or Cauchy) BCs, as well as for different bottom boundary conditions (fi...
by Jirka
Mon Jul 15, 2019 2:14 pm
Forum: Hydrus 1D
Topic: Trigger irrigation scheduling
Replies: 2
Views: 90

Re: Trigger irrigation scheduling

The model does not have an option to select only some part of the season for triggered irrigation. If you want to do that, you need to split the simulation into multiple simulations, while importing results of preceding simulation as the initial condition of the subsequent simulation.

J.