Search found 4983 matches

by Jirka
Thu Jun 04, 2020 4:29 pm
Forum: Hydrus 1D
Topic: numerical solution
Replies: 3
Views: 352

Re: numerical solution

Everyone is entitled to his beliefs, even if they may be entirely wrong. I, as should be apparent from the HYDRUS help (and from multiple posting in this discussion forum), give different recommendations:
" Max. Number of Iterations: Recommended and default value is 10."
J.
by Jirka
Wed Jun 03, 2020 3:33 pm
Forum: HYDRUS (2D/3D)
Topic: Well as constant head
Replies: 9
Views: 1526

Re: Well as constant head

Hi Thomas, Yes, you can certainly do it this way. My question is whether you need a 3D domain. Note that we have developed some tools (e.g., the reservoir BC) in 2D, which greatly simplify dealing with pumping or dry wells in 2D. Please note that you can find (and download) several examples involvin...
by Jirka
Tue Jun 02, 2020 7:06 pm
Forum: HYDRUS (2D/3D)
Topic: Hydrus solutions not converging outside of GUI
Replies: 2
Views: 670

Re: Hydrus solutions not converging outside of GUI

I do not think that it is possible that the program (h2D_calc.exe) would converge when run from inside the GUI and would not converge when run from outside the GUI, unless there are differences in input files. In both cases (inside and outside the GUI), the same code (e.g., h2d_calc.exe) is run and ...
by Jirka
Fri May 29, 2020 12:15 am
Forum: HYDRUS (2D/3D)
Topic: Discrepency between Variable Boundary Input and Total Surface Flux
Replies: 5
Views: 1277

Re: Discrepency between Variable Boundary Input and Total Surface Flux

While obviously HYDRUS can still have bugs (as any code has ; and I do worry about it), considering that it has (fortunately) thousands of users who are using it for over two decades, it is thus quite unlikely that there would be such apparent errors (in the computational module), such as wrongly ap...
by Jirka
Thu May 28, 2020 10:06 pm
Forum: HYDRUS (2D/3D)
Topic: Discrepency between Variable Boundary Input and Total Surface Flux
Replies: 5
Views: 1277

Re: Discrepency between Variable Boundary Input and Total Surface Flux

Hydrus assumes that atmospheric fluxes are vertical, not perpendicular to a sloping boundary, and thus are perpendicular to the horizontal projection of the atmospheric boundary. Rainfall is measured on a vertical plane, right?

J.
by Jirka
Thu May 28, 2020 3:17 pm
Forum: HYDRUS (2D/3D)
Topic: Discrepency between Variable Boundary Input and Total Surface Flux
Replies: 5
Views: 1277

Re: Discrepency between Variable Boundary Input and Total Surface Flux

The CumQAP column simply integrates the cumulative potential surface flux [int(Evap-Prec)dt] as defined at the input. Thus if this column shows a different value than you expect, then your input must be wrong. J.
by Jirka
Wed May 27, 2020 4:10 pm
Forum: Hydrus 1D
Topic: Snow Precipitation Equivalent
Replies: 4
Views: 1051

Re: Snow Precipitation Equivalent

The code should give you the SnowLayer exactly 1 cm (water equivalent). See attached test example. J.
00.zip
(11.05 KiB) Downloaded 240 times
by Jirka
Wed May 27, 2020 2:56 am
Forum: Hydrus 1D
Topic: Snow Precipitation Equivalent
Replies: 4
Views: 1051

Re: Snow Precipitation Equivalent

The snowfall should be entered in the "snow water equivalent", which is the amount of water contained within the snowpack. Since new powdery snow has a snow water density of about 10%, 1 cm of "snow water equivalent" would correspond to 10 cm of the snowpack. J.
by Jirka
Sun May 24, 2020 7:39 pm
Forum: Hydrus 1D
Topic: Field data optimization
Replies: 4
Views: 1453

Re: Field data optimization

1. It is a common practice to use one season for calibration and one for validation. 2. For reason of uniqueness, we do not recommend to optimize many parameters simultaneously. See, for example, Hopmans, J. W., J. Šimůnek, N. Romano, and W. Durner, Inverse Modeling of Transient Water Flow, In: Meth...
by Jirka
Fri May 22, 2020 12:32 am
Forum: Hydrus 1D
Topic: rRoot (T-level)/Transp (Meteo_out)
Replies: 5
Views: 1346

Re: rRoot (T-level)/Transp (Meteo_out)

In general, they should be the same. However, they can be different for some special conditions, such as when you consider interception. Meteo.out reports potential transpiration values calculated based on meteo conditions. T_level.out reports potential transpiration values as applied to root water ...
by Jirka
Thu May 21, 2020 9:10 pm
Forum: Hydrus 1D
Topic: Inpact of water content on heat transport
Replies: 6
Views: 1317

Re: Inpact of water content on heat transport

It seems that you have no idea what Hydrus actually does. Perhaps, you should first do some tutorials before you start asking further questions. CSIRO Tutorial eBook: https://www.pc-progress.com/Downloads/Public_Lib_H1D/HYDRUS-1D_Tutorial_V1.00_2018.pdf Rassam, D., J. Šimůnek, D. Mallants, and M. Th...
by Jirka
Thu May 21, 2020 5:12 pm
Forum: Hydrus 1D
Topic: rRoot (T-level)/Transp (Meteo_out)
Replies: 5
Views: 1346

Re: rRoot (T-level)/Transp (Meteo_out)

"rRoot" in the T_level.out file and "Trasp" in the Meteo.out file are potential transpiration rates in units of [L/T] and (mm/d). respectively. This means that they should be on the order of few mm/d. I do not see how they can potentially be 1400 or 1900 m (wrong units and wrong values). J.
by Jirka
Tue May 19, 2020 6:35 pm
Forum: HYDRUS (2D/3D)
Topic: Constant Head BC Ditch & Fluctuating GWT
Replies: 9
Views: 1681

Re: Constant Head BC Ditch & Fluctuating GWT

I have no more comments. To me, it seems that if you control pressure heads at the bottom of the transport domain and in the two ditches on the side, it should be pretty straightforward to control the pressure head gradients throughout the domain. I wonder if you somehow misinterpret how HYDRUS work...
by Jirka
Tue May 19, 2020 5:56 pm
Forum: Hydrus 1D
Topic: Inconsistency in flow simulation with pond in soil columns
Replies: 3
Views: 872

Re: Inconsistency in flow simulation with pond in soil columns

The problem with your project is that the entire soil column gets fully saturated and the free drainage BC is not appropriate BC for such conditions. See our description of this BC in the help: "A zero-gradient boundary condition can be used to simulate a freely draining soil profile. Such a situati...
by Jirka
Mon May 18, 2020 11:52 pm
Forum: Hydrus 1D
Topic: rRoot (T-level)/Transp (Meteo_out)
Replies: 5
Views: 1346

Re: rRoot (T-level)/Transp (Meteo_out)

First question: I do not see the difference between rRoot (1400 mm) and the transpiration in Meteo_out (1400 mm).

Another question: Unless you use an option when you specify directly net radiation, you need to use Julian days since radiation is then calculated based on that.

J.