Search found 5317 matches

by Jirka
Fri Oct 22, 2021 5:13 pm
Forum: HYDRUS (2D/3D)
Topic: High water balance error
Replies: 1
Views: 36

Re: High water balance error

This seems as a highly unrealistic problem. You have a rainfall of 3.24 m/d for one day on a thin layer (20 cm) of a material with a conductivity of 2.5 m/d. This material is underlain by a material has conductivity of less than 0.02 m/d, i.e., is practically impermeable. What do you expect can happ...
by Jirka
Fri Oct 22, 2021 4:49 pm
Forum: Hydrus 1D
Topic: Freezing module
Replies: 1
Views: 46

Re: Freezing module

I have just downloaded the computational module and the three examples (on freezing) from the Hydrus website. I ran (externally from the GUI) the program on these examples without any problems. J.
by Jirka
Wed Oct 20, 2021 5:48 pm
Forum: Hydrus 1D
Topic: Where to enter LAI for Interception when E and T are seperate BCs
Replies: 3
Views: 510

Re: Where to enter LAI for Interception when E and T are seperate BCs

vRoot is calculated whenever there is root water uptake. J.
by Jirka
Tue Oct 19, 2021 6:26 pm
Forum: Hydrus 1D
Topic: Unable to Reproduce Hydrus-1D and CXTFIT Comparative Simulations on Hydrus 1-D
Replies: 2
Views: 70

Re: Unable to Reproduce Hydrus-1D and CXTFIT Comparative Simulations on Hydrus 1-D

I have even posted the HYDRUS-1D example in the Hydrus library (in the group CXTFIT) at: https://www.pc-progress.com/en/Default.aspx?h1d-library. How much more can I help you?

J.
by Jirka
Mon Oct 18, 2021 4:48 pm
Forum: Hydrus 1D
Topic: capillary rise bondary conditions
Replies: 2
Views: 72

Re: capillary rise bondary conditions

First case: An atmospheric BC on the top and likely a specified pressure head at the bottom. Second Case: Hydrus cannot have an atmospheric BC at the bottom. Not sure how you want to impose precipitation and evaporation at the bottom in the lab. You likely just allow a seepage face at the bottom. I ...
by Jirka
Mon Oct 18, 2021 4:37 pm
Forum: Hydrus 1D
Topic: meteo data hourly vs daily
Replies: 2
Views: 85

Re: meteo data hourly vs daily

The line with the text “Daily values” in the Meteo.in file is only a comment line (not read, and thus inconsequential) that introduces the section with time series of meteo data. Time units are selected in the “Time Information” dialog window. It is up to the users to select the time units, and ente...
by Jirka
Fri Oct 15, 2021 10:00 pm
Forum: Hydrus 1D
Topic: Surface Level Water Content as Boundary Condition for Root Zone Soil Moisture Estimates
Replies: 2
Views: 77

Re: Surface Level Water Content as Boundary Condition for Root Zone Soil Moisture Estimates

No, there is not. HYDRUS solves the Richards equation governing variably-saturated water flow. Water contents with depth is the result of such calculations. You can compare that with measured values, and perhaps use it to estimate soil hydraulic properties, but you cannot use that in the forward sim...
by Jirka
Fri Oct 15, 2021 9:06 pm
Forum: Hydrus 1D
Topic: Definitions of Evapotranspiration quantities in Hydrus
Replies: 5
Views: 1793

Re: Definitions of Evapotranspiration quantities in Hydrus

See Chapter 2.7.2 (System-Dependent Boundary Conditions) of the manual. HYDRUS imposes potential evaporation as a surface flux BC. This flux condition is kept, and actual and potential evaporations are equal, until the surface pressure head reaches the hCritA value (about -150 m). Once this pressure...
by Jirka
Fri Oct 15, 2021 5:43 pm
Forum: Hydrus 1D
Topic: dual permeability + root growth
Replies: 1
Views: 89

Re: dual permeability + root growth

We are not aware of any error associated with root growth in the dual-permeability model.

Isotopes: This option is currently available only in the standard module (not in the dual-permeability model).

J.
by Jirka
Wed Sep 29, 2021 5:24 pm
Forum: HYDRUS (2D/3D)
Topic: A_Level.out
Replies: 3
Views: 252

Re: A_Level.out

There are two other chapters in the manuscript that describe how atmospheric BC is handled. 2.7.2.1. Atmospheric Boundary Conditions 5.3.6. Atmospheric Boundary Conditions and Seepage Faces The former chapter explains differences between potential and actual fluxes. The potential flux is used as a B...
by Jirka
Tue Sep 28, 2021 4:44 pm
Forum: HYDRUS (2D/3D)
Topic: A_Level.out
Replies: 3
Views: 252

Re: A_Level.out

The output file A_Level.out is described in detail in the technical manual (Table 11.7, page 215). J.
by Jirka
Thu Sep 23, 2021 4:12 pm
Forum: HYDRUS (2D/3D)
Topic: coefficients type
Replies: 1
Views: 125

Re: coefficients type

This is, obviously, described in the technical manuals of both HYDRUS-1D and HYDRUS (2D/3D) (see eq. 3.13 and 3.14). It would not make sense to copy here the text from the manuals. J.
by Jirka
Wed Sep 22, 2021 4:29 pm
Forum: HYDRUS (2D/3D)
Topic: limiting printing to scren
Replies: 2
Views: 172

Re: limiting printing to scren

No. You can either disable it completely or allow it at each time step. J.
by Jirka
Sat Sep 18, 2021 8:38 pm
Forum: Hydrus 1D
Topic: Water Content Post-processing
Replies: 1
Views: 286

Re: Water Content Post-processing

Quote “So what wrong with this problems?” Problem seems to be your basic understanding of soil physics. A zero pressure head BC does not mean a zero flux BC, it means a zero pressure head at the boundary. Note that the zero pressure head corresponds to full saturation (see the retention curve). If y...
by Jirka
Wed Sep 15, 2021 9:20 pm
Forum: Hydrus 1D
Topic: Two questions on inverse modeling and one on IC
Replies: 1
Views: 171

Re: Two questions on inverse modeling and one on IC

Q1: If you use type 12 (for pressure heads) or 13 (for water contents), then it should be -40, e.g., -40 0.35 13 iPrint Weight If you use type 1 (for pressure heads) or 2 (for water contents), then you should give the observation node number, e.g., Time 0.35 2 iObs Weight You should be able to see i...