Precipitation interception / root distribution

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elizabeth.ramirez.z
Posts: 1
Joined: Sat Oct 26, 2019 4:03 am
Location: Chile

Precipitation interception / root distribution

Post by elizabeth.ramirez.z » Mon Nov 04, 2019 2:32 am

Hi,
I am using hidrus to estimate the water consumption of pinus radiata at 35 ° south latitude (Chile). I have some questions.
1. Precipitation interception: I am using the model from Von Hoyningen-Hüne [1983], Braden [1985] and van Dam et al. [1997]. I wanted to know how I can calculate parameter a. I read that for ordinary agricultural crops 0.25 mm / d, but I guess that pines are not "ordinary crops"

I looked for van Dam et al. [1997] but I didn't find how to calculate parameter "a". Also, I looked at Von Hoyningen-Hüne [1983], Braden [1985] but I only found one but it was an old document that was scanned (German language), so I couldn't understand how "a" was calculated.

2. Root distribution: in the profile information, I don't understand what the range of -1 to 1.5 means ... For example, when there are no roots I put 0, but when I use -1.5 ... And if I had a horizon with abundant roots (the maximum in the whole profile) use 1? (I did not find this detailed in the manual)
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Jirka
Posts: 4798
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Precipitation interception / root distribution

Post by Jirka » Mon Nov 04, 2019 2:55 am

a) I have no opinion on how to get the "a" parameter for pines. I think it should be possible to find it in the literature.
b) The values entered for root distribution are relative number. Value of 10 (location 1) compare to 1 (location 2) means that the root density is 10 times larger at location 1 than 2. The program than normalized entered values so that its integral over depth is equal to 1.

J.

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