Search found 71 matches

by liyonghh
Tue Jan 05, 2010 3:58 pm
Forum: Hydrus 1D (old free version)
Topic: About Pressure Vs Preci.
Replies: 1
Views: 3579

About Pressure Vs Preci.

Dear Jirak, I simulated a soil column using Hydrus-1D. Atmospheric BC with surface layer (5cm) was set as top BC. Followings are the input precipation/irrigation data. day Preci.(cm) 15 1.4 16 0.3 17 2.2 18 0 19 0 20 0 <font color="red"><b>21 5.3 22 0</b></font id="red"> 23 0 24 0 26 0 27 0 28 5 29 ...
by liyonghh
Wed Dec 30, 2009 12:30 pm
Forum: Hydrus 1D (old free version)
Topic: A doubt about Bottom Flux
Replies: 6
Views: 9156

Thanks.It is a good reference.
by liyonghh
Tue Dec 29, 2009 2:58 pm
Forum: Hydrus 1D (old free version)
Topic: A doubt about Bottom Flux
Replies: 6
Views: 9156

Thanks. I have another question about soil hydraulic model(single porosity model). In Hydrus-1D,four model (van Genuchten-Mualem,Modified van Genuchten,Brooks-Corey,Kosugi(log-normal)) are adopted for soil water flow simulation. As I simulated (flooded paddyfield), which model should be selected bet...
by liyonghh
Mon Dec 28, 2009 3:15 am
Forum: Hydrus 1D (old free version)
Topic: A doubt about Bottom Flux
Replies: 6
Views: 9156

Thanks. I found tha water balance is feasible. Another question: In the simulated results, if the <b>cum.infiltration</b> comprised (1)cum. Actual root water uptake,(2)cum.bottom flux,and (3)the difference of soil water storage? And if the Cum. Evaporation and Cum. Surface runoff were parts of the c...
by liyonghh
Mon Dec 21, 2009 12:32 pm
Forum: Hydrus 1D (old free version)
Topic: A doubt about Bottom Flux
Replies: 6
Views: 9156

A doubt about Bottom Flux

Dear Jirka, I set a soil column with four layers as followings: Qr Qs Alpha n Ks l 0.0729 0.4356 0.0056 1.6382 15.88 0.5 0.0712 0.4232 0.0067 1.579 6.65 0.5 0.0485 0.3739 0.0063 1.6277 25.38 0.5 0.0469 0.3988 0.0064 1.6507 49.08 0.5 This was used to simulate a flooding paddy field, which contain 5 c...
by liyonghh
Mon Nov 30, 2009 12:42 pm
Forum: Hydrus 1D (old free version)
Topic: About divided simulated period
Replies: 4
Views: 6854

Thanks.
by liyonghh
Mon Nov 30, 2009 1:10 am
Forum: Hydrus 1D (old free version)
Topic: About divided simulated period
Replies: 4
Views: 6854

Sorry,Dear Jirka, I still have not understand it. I have tried to write two kinds of time variable BC as folowings: <b>(1)</b> <b>14 0 0.14 100000 0.15</b> 15 1.4 0.14 100000 0.15 16 0.3 0.15 100000 0.25 ......................................... 54 3.1 0.05 100000 0.15 55 1.44 0.05 100000 0.28 <b>(2...
by liyonghh
Sun Nov 29, 2009 3:05 pm
Forum: Hydrus 1D (old free version)
Topic: About divided simulated period
Replies: 4
Views: 6854

About divided simulated period

Hi,everybody, I divided the simulated period into two stage:1-14days and 15-55days. The first stage used the "Atmospheric BC with surface runoff", and the second used the "Atmospheric BC with surface layer". The water contents of the soil column on 14th day was used as the intial water contents of s...
by liyonghh
Wed Nov 11, 2009 7:24 am
Forum: Hydrus 1D (old free version)
Topic: About root water uptake
Replies: 4
Views: 6425

Thanks.
by liyonghh
Mon Nov 09, 2009 2:49 pm
Forum: Hydrus 1D (old free version)
Topic: About root water uptake
Replies: 4
Views: 6425

It is so great. Thank you very much.
Could give me some advices about p0pt,p2h,p2l,p3,r2h,r2l for rice root water uptake? Any help would be desired.
by liyonghh
Mon Nov 09, 2009 2:24 pm
Forum: Hydrus 1D (old free version)
Topic: About root water uptake
Replies: 4
Views: 6425

About root water uptake

Hi, everybody. I simulated a root water uptake using Fedds model. The parameters of Fedds model were as followings: p0=10,p0pt=0,p2h=-500,p2l=-900,p3=-8000,r2h=0.5,r2l=0.1 The potential transpiration of everyday was specified. And the standing water was contained on surface soil in most time of rice...
by liyonghh
Wed Aug 19, 2009 1:25 am
Forum: Hydrus 1D (old free version)
Topic: Feddes root water uptake
Replies: 0
Views: 11658

Feddes root water uptake

Hi,everybody. In hydrus-1D,there are seven parameters including P0, POpt,P2H,P2L,P3,r2H,r2L. According to the Help manual, the r2H,r2L currently set at 0.5 and 0.1 cm/day. I could not sure that the P0, POpt,P2 and P3 are corresponding to the h1, h2, h3 and h4 in the Help Manual. If it is right, how ...
by liyonghh
Tue May 05, 2009 4:25 pm
Forum: Hydrus 1D (old free version)
Topic: How to obtain the solute quantity through runoff?
Replies: 4
Views: 7613

Thank you very much.Good luck!
by liyonghh
Tue May 05, 2009 4:04 pm
Forum: Hydrus 1D (old free version)
Topic: How to obtain the solute quantity through runoff?
Replies: 4
Views: 7613

Thank you very much for your answer.
Another question:how can I get the cum.solute (NO3-) loss by denitrification?
Good wishes!
by liyonghh
Tue May 05, 2009 3:21 pm
Forum: Hydrus 1D (old free version)
Topic: How to obtain the solute quantity through runoff?
Replies: 4
Views: 7613

How to obtain the solute quantity through runoff?

Hi everybody,
How can I get the cum.solute flux (or quantity) through surface runoff?
Thank you very much.