Dear all,
I’d like to share some results from Hydrus1D, just to know if someone could provide me some hint about what’s happening.
Main features of the model are:
 Water, vapor and heat model. No transpiration
 Time units: days. 3651 days (10 years)
 4000 cm (40 m) profile.
 Pressure head of 7 m at the botton (there is water table at 33 m depth)
 Atmospheric BC with Surface runoff at the top
 Temperature BC for both botton and top for the heat model.
 Only 1 subregion for water balance

Main results for the water balance (units in cms) for the complete simulation period:
 CumActSurf, sum(Vtop), 329
 CumActBot sum(vBot), +32
 sum(Runoff), 0
 WaterVolume change in the whole profile, 622(t=end)271(t=0)=351
 sum (Infil), 694
 sum (evap), 602
 Precipit 641
Doubts:
 Difference between sum(infil) and sum(evap) (i.e. +602694= 92cm) = should not be equal to sum(vTop) (i.e, 329cm )?
 Sum(vtop) +sum(vBot) (392(into the domain)+32(into the domain)=424 cm) should not be equal to difference in volume for the whole profile(i.e, 351 cm)?
 Even that precipitation is sinusoidal variated by HYDRUS, there is norunoff, which sounds somehow strange
Any tip about these results??
I attached the complete model just in case someone wants to make a deeper look.
https://drive.google.com/file/d/1KBSxUa ... sp=sharing
Thanks in advance
Javier
Water balance
Re: Water balance
I do not have time to look at your simulations. Check out the reported water balance in Balance.out file. HYDRUS reports both absolute and relative mass balance errors in this file. If these are small, then the mass balance calculations in the run are OK, and your own calculations (on side) are wrong. J.
Re: Water balance
Checking the Balance.out file was the first step I made after detecting the problem and before adressing the question into the forum. There was no problem there.
After making some test, I would like to share my point of view about what is happening for other Hydrus users:
 sum(Infil) variable does consider water entering in vapor and liquid form. I concluded that because it's impossible to have 694 cm of infiltration when the precipitation is 640 cm.
 In the same way, sum (Evap) does consider both water phases. I concluded that after running the same moddel without vapor component. In that other model without vapor the evaporation was 325 cm so the hugh increase in the evaporation (from 325 to 602 cm) must came from the vapor phase.
 However, sum(vTop) does not included the vapor phase, so it considers only the movement of water through the top boundary considering the components included in the liquid water flow process. If the sum(vTop) considered the vapor, it should be equal to the difference between sum(Infil) and sum(Evap).
The water balance from the Balance.out file, considers only the components from the liquid water flow process. I concluded that because the water balance along the complete period is in agreement with sum(vTop) and sum(vBot), which do not consider the vapor process, as stated before.
Best
Javier.
After making some test, I would like to share my point of view about what is happening for other Hydrus users:
 sum(Infil) variable does consider water entering in vapor and liquid form. I concluded that because it's impossible to have 694 cm of infiltration when the precipitation is 640 cm.
 In the same way, sum (Evap) does consider both water phases. I concluded that after running the same moddel without vapor component. In that other model without vapor the evaporation was 325 cm so the hugh increase in the evaporation (from 325 to 602 cm) must came from the vapor phase.
 However, sum(vTop) does not included the vapor phase, so it considers only the movement of water through the top boundary considering the components included in the liquid water flow process. If the sum(vTop) considered the vapor, it should be equal to the difference between sum(Infil) and sum(Evap).
The water balance from the Balance.out file, considers only the components from the liquid water flow process. I concluded that because the water balance along the complete period is in agreement with sum(vTop) and sum(vBot), which do not consider the vapor process, as stated before.
Best
Javier.