root growth visualisation

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tomgreen
Posts: 11
Joined: Sun Dec 03, 2017 9:13 am
Location: Israel

root growth visualisation

Post by tomgreen » Fri Mar 15, 2019 12:59 pm

hi,
i'm trying to simulate water and nitrogen uptake in hydrus 2d, (version 3) and want to how much these are affected by the root zone density distribution. in order to grow the roots over time i chose "using a table" and "vrugt et al 2000" for the shape of the root zone. after entering the root depth over time in the table, i noticed in the 'selector.in' file that there is another column of digits next to these depth values over time, and when i change the values here (were set to zero) i can see a response in the plant uptake.

what are the values in this column?
and what are the numbers labled rZm, rZ0 and rA ?
can these root density distributions be visualized in the GUI?
root growth selector file.png
root growth selector file.png (122.97 KiB) Viewed 232 times
thanks,
tom.

Jirka
Posts: 4714
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: root growth visualisation

Post by Jirka » Fri Mar 15, 2019 4:43 pm

rZm, rZ0 and rA are the shape parameters for the Vrugt model. These are specified at Edit->Domain Properties->Parameters for Root Distribution (or from Navigator Bar -> Distribution Parameters).

There are three columns in the table: Time, rooting depth, and rooting width (as you should expect for 2D applications). This is given in "Root Growth Parameter" dialog window.

Root Water Uptake is one of the outputs under "Results" (similarly as Pressure Heads, Water Contents, etc).

J.

tomgreen
Posts: 11
Joined: Sun Dec 03, 2017 9:13 am
Location: Israel

Re: root growth visualisation

Post by tomgreen » Sat Mar 16, 2019 3:21 pm

hi thanks,
so then i have root zone depth and width over time, rZm i don't need as i already give it in the table of depths,
but for shape parameters i would expect to see the depth and radius of maximum intensity and and pz and px parameters, so 2 parameters for each dimension. where can i find the shape parameters for the x dimension?
tom

Jirka
Posts: 4714
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: root growth visualisation

Post by Jirka » Sat Mar 16, 2019 7:08 pm

This is all described in detail in the technical manual. J.

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