[GRASS-user] r.soils.texture question

GRASS GRASS user
1

Dear all,
I am looking at the DAT file for USDA soil texture classification for the r.soil.texture addon.
I have a couple of questions.

  1. the class silt-loam appears twice (number 8 and 12). Is this intentional and needed for the calculations?

  2. Could you please explain the structure of the DAT file? As example
    1
    6
    0 0 20 45 45 0
    100 60 40 40 55 100

First line: I think is the class value as written in the pixel.
Second line: not sure
Following two lines: I think they are somehow the limits of sand, silt and clay. However I can not really understand in which order.

Thank you very much in advance
Laura

2

Dear Laura,

I am sorry if I jump to your message without answering your question :pray:

Are you the author of this paper, “Modelling the extent of northern peat soil and its uncertainty with Sentinel: Scotland as example of highly cloudy region”?

Thank you.

Best regards,

On Jun 12 2020, at 1:10 pm, Laura Poggio laura.poggio@gmail.com wrote:

Dear all,
I am looking at the DAT file for USDA soil texture classification for the r.soil.texture addon.
I have a couple of questions.

  1. the class silt-loam appears twice (number 8 and 12). Is this intentional and needed for the calculations?

  2. Could you please explain the structure of the DAT file? As example

1
6
0 0 20 45 45 0
100 60 40 40 55 100

First line: I think is the class value as written in the pixel.
Second line: not sure
Following two lines: I think they are somehow the limits of sand, silt and clay. However I can not really understand in which order.

Thank you very much in advance
Laura

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3

*.dat files are derived from TALCPP ( https://www.tandfonline.com/doi/abs/10.1081/CSS-120017410). The values describe polygons coordinates for different class inside the texture triangle. In r.soils.texture is implemented an algorithm to check if a single point is inside or outside a texture polygon. If the point is inside it is labeled with the correspondent texture code and used to build a texture map.
By

···

Dott. Gianluca Massei, PhD

4

Hi Gianluca,
thanks for the explanation. It was very useful. Thanks to your explanations I managed to modify the DAT file to reproduce the USDA-NRCS texture triangle. We are doing some final checks. After that, if you are interested, I can share the DAT file.

Thanks a lot!
Laura

On Fri, 12 Jun 2020 at 22:27, Gianluca Massei <agr.gianluca.massei@gmail.com> wrote:

*.dat files are derived from TALCPP ( https://www.tandfonline.com/doi/abs/10.1081/CSS-120017410). The values describe polygons coordinates for different class inside the texture triangle. In r.soils.texture is implemented an algorithm to check if a single point is inside or outside a texture polygon. If the point is inside it is labeled with the correspondent texture code and used to build a texture map.
By

Il giorno ven 12 giu 2020 alle ore 08:10 Laura Poggio <laura.poggio@gmail.com> ha scritto:

Dear all,
I am looking at the DAT file for USDA soil texture classification for the r.soil.texture addon.
I have a couple of questions.

  1. the class silt-loam appears twice (number 8 and 12). Is this intentional and needed for the calculations?

  2. Could you please explain the structure of the DAT file? As example
    1
    6
    0 0 20 45 45 0
    100 60 40 40 55 100

First line: I think is the class value as written in the pixel.
Second line: not sure
Following two lines: I think they are somehow the limits of sand, silt and clay. However I can not really understand in which order.

Thank you very much in advance
Laura

grass-user mailing list
grass-user@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-user

–

Dott. Gianluca Massei, PhD

5

yes, of course!

GM

···

Dott. Gianluca Massei, PhD