Search found 26 matches

by Mitra
Wed Apr 14, 2021 7:34 am
Forum: Hydrus 1D
Topic: Pressure data and model do not match
Replies: 8
Views: 449

Re: Pressure data and model do not match

Actually, it seems the boundary condition at the bottom is alway seepage face (no matter which suction I apply); probably because of a membrane at the bottom. However, I am thinking how the suction applied should best be represented in the model (the model works with higher Ks at higher suctions) ?
by Mitra
Thu Apr 08, 2021 12:05 pm
Forum: Hydrus 1D
Topic: Pressure data and model do not match
Replies: 8
Views: 449

Re: Pressure data and model do not match

I thought as I am applying a suction of 30kPa in reality, so I can use a seepage face boundary condition of -300 cm (equivalent to 30kPa) at the bottom, does it seem sensible to you? This boundary condition still gives me, the lowest soil moisture at the bottom of the soil column while in my setup a...
by Mitra
Wed Apr 07, 2021 5:20 pm
Forum: Hydrus 1D
Topic: Pressure data and model do not match
Replies: 8
Views: 449

Re: Pressure data and model do not match

I know theoretically what does each condition represents, what I do not know is which condition my experimental setup represents at the bottom boundary. I have a pump that applies a high suction pressure to a bottle through a tube, and the bottle is completely closed and connected to the bottom of l...
by Mitra
Tue Apr 06, 2021 11:36 am
Forum: Hydrus 1D
Topic: Pressure data and model do not match
Replies: 8
Views: 449

Re: Pressure data and model do not match

Actually, what you mentioned is very correct. I applied a constant suction at the bottom of my soil column (-300cm) and in my model, suction pressure of -300cm (I have also tried seepage face at this suction pressure) as the bottom boundary condition without considering evaporation (measured values ...
by Mitra
Thu Mar 25, 2021 9:35 am
Forum: Hydrus 1D
Topic: Pressure data and model do not match
Replies: 8
Views: 449

Pressure data and model do not match

Hello, I have pressure (in the middle), moisture, and outflow data for a soil column. When I use HYDRUS to reproduce the data. I am successful in reproducing the flux, and soil moisture; however, when I compare the pressure values ( where negative values indicate absence of fully saturated condition...
by Mitra
Wed Mar 03, 2021 9:58 am
Forum: HP1 (HYDRUS-1D - PHREEQC)
Topic: gaseous by-product
Replies: 1
Views: 299

gaseous by-product

Hello I had a question regarding reactive transport of solutes. I am planning to use HP1 for the transport of a reactive solute (with a gaseous by-product) and I am interested to quantify the amount of this gaseous by-product that exit the system. From what I have learned in HYDRUS I can account for...
by Mitra
Fri Feb 19, 2021 9:09 pm
Forum: Hydrus 1D
Topic: Potential transpiration vs Actual transpiration
Replies: 1
Views: 605

Potential transpiration vs Actual transpiration

Hello, I am thinking if potential transpiration in HYDRUS is always equivalent to potential transpiration or T_a<=T_p? As T_p is multiplied by alpha in Feddes law, when we are in the pressure zones (in one node) less than optimal condition (h3-h4) or higher than optimal condition (h1-h2), we are no ...
by Mitra
Wed Feb 17, 2021 9:53 am
Forum: Hydrus 1D
Topic: hysteresis
Replies: 1
Views: 309

hysteresis

Hello, I am trying to account for hysteresis in my soil column. In the manual the subject is discussed on pages 31-35. However, I cannot find the parameter equivalent to "\theta_m^d" among the parameters when using HYDRUS software. Is it the same as theta_s^d? Also, I cannot see exactly the differen...
by Mitra
Thu Jan 28, 2021 1:02 pm
Forum: Hydrus 1D
Topic: initial condition in saturated soil column with high suction at the bottom
Replies: 3
Views: 500

Re: initial condition in saturated soil column with high suction at the bottom

I think that I didn't explain myself well. If I have a 60 cm soil column that is initially fully saturated (with ponding water of 2 cm accumulated at the top), and it is exposed to a suction of -800 cm at the bottom. What should I change in the attach project (example.zip example.zip ) so I do not f...
by Mitra
Wed Jan 27, 2021 9:45 am
Forum: Hydrus 1D
Topic: initial condition in saturated soil column with high suction at the bottom
Replies: 3
Views: 500

initial condition in saturated soil column with high suction at the bottom

I am trying to use HYDRUS to simulate transport in soil columns that start in fully saturated condition and simultaneous with opening the bottom valve, a high level of suction is applied (-300 cm to -800 cm). Now, I would have liked to ask you 2 questions. My simulations does not even pass the first...
by Mitra
Tue Jan 21, 2020 5:03 pm
Forum: Hydrus 1D
Topic: Inverse modeling of HYDRUS-1D.
Replies: 5
Views: 29798

Re: Inverse modeling of HYDRUS-1D.

Thanks a lot for sharing the code, I will highly appreciate it if you could confirm whether my understanding on v_j is correct? For example, if I have 2 datasets one with a mean of 0.3 and 10 points and the other with a mean of 0.1 and 20 points, they are weighted by the values of (1/3) and (1/2) re...
by Mitra
Tue Jan 21, 2020 3:59 pm
Forum: Hydrus 1D
Topic: Inverse modeling of HYDRUS-1D.
Replies: 5
Views: 29798

Re: Inverse modeling of HYDRUS-1D.

Thanks for your reply. I have an additional question about the objective function that I couldn't find its answer in the references provided in HYDRUS-1D interface and manual. If we assume to only have the data on the first term in the objective function introduced in the manual (eq. 9.1). There are...
by Mitra
Wed Jan 15, 2020 12:33 pm
Forum: Hydrus 1D
Topic: Net mass tracer flux moving downward
Replies: 1
Views: 1641

Net mass tracer flux moving downward

Dear Jirka, I am interested to compute a value similar to "cvBot" in the solute.out the file for an observation node within the soil column and I hope you can guide me. Basically, how can I compute the net tracer mass flux that is moving downward at an observation node within the soil column using t...
by Mitra
Tue Jan 14, 2020 3:04 pm
Forum: Hydrus 1D
Topic: Inverse modeling of HYDRUS-1D.
Replies: 5
Views: 29798

Inverse modeling of HYDRUS-1D.

Dear Jirka I am using HYDRUS-1D to inversely calibrate my hydraulic parameters and the longitudinal diffusivity against soil and tracer data. I have found reasonable numbers with low errors, still, I was interested to check the procedure that I use with you to make sure that I am doing it correctly ...
by Mitra
Tue Jan 14, 2020 2:44 pm
Forum: Hydrus 1D
Topic: Flux data in observation nodes
Replies: 6
Views: 6471

Re: Flux data in observation nodes

Dear Jirka,

I was wondering if I could have access to this modified version of HYDRUS-1D discussed in this post in which fluxes for observation nodes are printed instead of the Obs_Node.out.

Thanks in advance.

Mitra