Water stored/retained by a peat profile in HYDRUS 1-D

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AmeyTilak
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Joined: Tue Feb 04, 2020 2:25 pm
Location: Ireland

Water stored/retained by a peat profile in HYDRUS 1-D

Post by AmeyTilak » Tue Feb 04, 2020 2:57 pm

Hello Sir,

I am simulating 50 cm peat profile having vertical flow direction, constant flux at bottom, atmospheric BC at top and variable rainfall and evapotranspiration conditions. I have two initial water table depths i.e. at 5 cm and 15 cm. I run the model and look at theta vs days and h pressure head vs days. I also have the water retention curve theta vs. h. Does the model have any output which quantifies the amount of water stored/retained by the peat profile at 5 cm and 15 cm initial water table depths?

Jirka
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Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Water stored/retained by a peat profile in HYDRUS 1-D

Post by Jirka » Tue Feb 04, 2020 3:55 pm

I'm not sure if I understand the question. I would say that "water content" tells me how much water is stored or retained at a particular depth. You can get this info as a function of time for observation nodes. If you are interested in the flux through a particular depth, you can get that also for observation nodes (if you select that option in Print Information). If you want cumulative value, then you need to simply (manually, e.g., in Excel) integrate the flux. J.

AmeyTilak
Posts: 7
Joined: Tue Feb 04, 2020 2:25 pm
Location: Ireland

Re: Water stored/retained by a peat profile in HYDRUS 1-D

Post by AmeyTilak » Wed Feb 05, 2020 3:42 pm

Thank you Sir for the kind reply.

I looked at the nodes output file and for each node it provides information on pressure head, flux, great thing to plot and understand the dynamics.

But, wanted to quantify water holding capacity of a given peat profile from flood mitigation point of view, i.e. difference between field capacity and wilting point. Does the model have any such outputs. Thank you once again for the kind reply.

Jirka
Posts: 4847
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Water stored/retained by a peat profile in HYDRUS 1-D

Post by Jirka » Wed Feb 05, 2020 6:13 pm

Hydrus does not recognize these terms (field capacity, wilting point). These are terms usually used in the tipping bucket models, not in those based on the numerical solution of the Richards equation. However, it should be very simple for you to use the HYDRUS outputs and make these calculations manually. J.

AmeyTilak
Posts: 7
Joined: Tue Feb 04, 2020 2:25 pm
Location: Ireland

Re: Water stored/retained by a peat profile in HYDRUS 1-D

Post by AmeyTilak » Thu Feb 06, 2020 10:52 am

Thank you very much Sir for the kind reply.

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