Search found 28 matches

by Cranberry1
Mon Jul 14, 2014 8:33 pm
Forum: Hydrus 1D
Topic: Over and underestimation of parameters
Replies: 4
Views: 2531

Re: Over and underestimation of parameters

Hi Jirka
Yes , water content is a volume in cm3/cm-3.

Thank you
by Cranberry1
Mon Jul 14, 2014 7:38 pm
Forum: Hydrus 1D
Topic: Over and underestimation of parameters
Replies: 4
Views: 2531

Re: Over and underestimation of parameters

Hi Jirka, Regarding hydraulic parameter optimization. I’m working with a sandy soil and I have a limit of saturated water content equal to 0.7 cm/hour. The problem is that when I run the parameter optimization, the optimizer of HYDRUS gives me 2.74 cm/hour. Two questions: why does HYDRUS give me thi...
by Cranberry1
Fri Jul 11, 2014 2:41 am
Forum: Hydrus 1D
Topic: Over and underestimation of parameters
Replies: 4
Views: 2531

Over and underestimation of parameters

Hi Jirka, I'm working with inverse methods in order to optimize Van Genutchen parameters. The main problem that I am experiencing is that I have underestimation or overextimation of parameters. is this considered normal with Hydrus-1D? Do you have any articles that discuss the Under and overestimati...
by Cranberry1
Mon Jul 07, 2014 4:24 pm
Forum: Hydrus 1D
Topic: Retention curve
Replies: 3
Views: 2264

Re: Retention curve

Hi Jirka, Thank you for your prompt response. What is the difference between watercontent data (Theta) in the Check.out file and watercontent (WC) in the Inverse Solution Information window? I also noticed that the WC is variable but Teta is always constant. There is H in the check-out file whereas ...
by Cranberry1
Sun Jul 06, 2014 9:04 pm
Forum: Hydrus 1D
Topic: Retention curve
Replies: 3
Views: 2264

Retention curve

Hi Jirka,

Where can I find the data to draw the curve retention (water content vs pressure head)? Thank you for your assistance.

Cordially,

Cranberry1
by Cranberry1
Sun Feb 09, 2014 12:20 am
Forum: Hydrus 1D
Topic: How to copy a window from Hydrus 1-D
Replies: 1
Views: 1392

How to copy a window from Hydrus 1-D

Hi Jirka,

I would like to copy an open window from Hydrus 1-D without taking the background. For example, I would like to take the Water Flow Parameters window and copy it elsewhere. How should I proceed?

Best regards.
by Cranberry1
Mon Jan 13, 2014 5:27 am
Forum: Hydrus 1D
Topic: Root water uptake
Replies: 3
Views: 2333

Re: Root water uptake

Thank you Jirka. Your answer was quite helpful. A small question however: does hysteresis exist in sandy soil? Thanks in advance.
by Cranberry1
Sun Jan 12, 2014 2:12 am
Forum: Hydrus 1D
Topic: Root water uptake
Replies: 3
Views: 2333

Root water uptake

Hi Jirka, In your book Soil Physics with Hydrus p. 221 figure 5.33, you mention root distribution resembles triangular distribution (minimum = 0, maximum = 1). When I make it uniform distribution (minimun = 1, maximum = 1), I obtain inconsistent results. Does triangular distribution consist of appro...
by Cranberry1
Sun Jan 12, 2014 1:53 am
Forum: Hydrus 1D
Topic: Hysteresis in the soil water retention curve
Replies: 0
Views: 2364

Hysteresis in the soil water retention curve

Hi everyone, I have a question regarding the presence of the hysteresis effect in sandy soil. I haven't yet found any references concerning the proportion of this effect in sandy soil. Is it possible to find this effect in part of a field and not in another part (of the same field)? In other words, ...
by Cranberry1
Thu May 17, 2012 12:01 am
Forum: Soil Physics with Hydrus
Topic: Pressure head vs Time
Replies: 0
Views: 4931

Pressure head vs Time

Hi Mr. Jirka,

Why is it that in the post-processing I cannot find h(t). Every time I attempt it, I get time versus all pressure head. Can you please help how I can find h(t) simulated when I input Ep, Pt, Ks, Bc and BI.

Best regards,

Suzanne
by Cranberry1
Tue May 15, 2012 3:33 am
Forum: Soil Physics with Hydrus
Topic: Root distribution
Replies: 8
Views: 12202

Hi Mr. Jirka, Why is it that in the post-processing I cannot find h(t). Every time I attempt it, I get time versus all pressure head. Can you please demonstrate how I can find h(t) simulated when I input Ep, Pt, Ks, Bc and BI. Best regards, Suzanne N.B. Depth of soil profile = 100 cm BC = Upper atmo...
by Cranberry1
Sun May 13, 2012 12:04 am
Forum: Soil Physics with Hydrus
Topic: Root distribution
Replies: 8
Views: 12202

Hi Jirka, I am unable to calculate the intial time step, minimum time step and maximum time step. As you suggested, I adopted 0.01d as my initial time step and 1s as my minimum time step but I get an error message that refuses my minimum time step. If my initial time is 0 and my final time is 600 ho...
by Cranberry1
Sun Apr 22, 2012 10:33 pm
Forum: Soil Physics with Hydrus
Topic: Root distribution
Replies: 8
Views: 12202

Hi Mr. Jirka,

Thanks for everything.

Regards,

Cranberry1
by Cranberry1
Sun Apr 22, 2012 8:43 pm
Forum: Soil Physics with Hydrus
Topic: Root distribution
Replies: 8
Views: 12202

Hi Mr. Jirka, Could you please send me a copy of your article Parameter Optimization and Nonlinear Fitting, In: Methods of Soil Analysis, Part 1, Physical Methods, Chapter 1.7, Eds. J. H. Dane and G. C. Topp, Third edition, SSSA, Madison, WI, 139-157, 2002. Unfortunately, I wasn't able to find it on...
by Cranberry1
Tue Apr 10, 2012 7:17 pm
Forum: Hydrus 1D
Topic: Input Hydraulic Conductivity
Replies: 3
Views: 1365

Hi Jirka, I'm so sorry but I think a part of my question was erased before I sent it. Here is my question. Suppose I have a drain and the conductivity on top of the drain is different than the one underneath it in one unique material. In the event of one material, am I able to input more than one hy...