Hello,

The initial answer is:

"Simply converts polygon features to a raster (if I understood well)"

Would you please elaborate more about your query!

Do you have point data/just three separate polygons/one polygon with three soil texture type?

If your dataset is in txt format with lat\long\percentage clay\silt\sand, you may import the data file into ArcMap using Add Data button. Then, right click on the layer>Display XY data> Assign X, Y andZ fields (Z should be the value field) to view it in point format. Next, right click on the point layer and export it into a shape file.

Thereafter, you can interpolate the point layer into a TIN and thereafter convert the TIN into a Raster. You can develop separate rasters for clay, silt and sand.

Create TIN: https://www.youtube.com/watch?v=HQH31j3NbS0

TIN to Raster: https://www.youtube.com/watch?v=ZrfTuwY1_s4

Hope this will help.

Sorry but it seems that my question was misunderstood I think. I have already three raster layers of silt, sand and clay percentage with pixel size of 30 m GSR. I am looking for an extension or adds in to look in the three aforementioned layers and come to a resultant nominal layer of soil texture based on triangular soil texture lookup table?

is there anyone who can help me in this regards?

Many thanks in advance.

Sorry, I've misunderstood your question. I'm not aware of any ArcGIS add-on/extension to create soil type map from soil texture. However, you can gice a try by referring to the 'calculations' sheet of the attached excel file (source:https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/?cid=nrcs142p2_054167) and compile it into a python model.

Dr. Ebrahimi,

Thanks for extra information.

Interesting question! and maybe not going to be that easy.

The first thing that came to my mind was transferring the attribute table of silt, sand and clay percentages and using an excel template to calculate the soil texture, then adding the results to a new created raster file a “soil texture”. But was not able to find an excel work sheet to calculate large number of values (according to the pixel size counts). The available excel-based calculators just feed one sample set per run (As shared in the previous comment by @Indishe)

There are some excel add-ins which uses vba to determine soil texture type.

If there is a formula for determining soil texture, the raster calculator would work well as a possible option.

A lookup table having columns clay/silt/sand/texture is needed based on possible combination of 3 soil categories (summation equals 100), as you said in your query.

The last approach is using the interpolation techniques with different methods.

The Harmonized World Soil Database  HWSD may also be used to acquire general soil information at two soil horizons. HWSD is a global soil database framed within a Geographic Information System (GIS) and contains up-to-date information on world soil resources. Which you can integrate it with other spatial maps. Study the following website: http://webarchive.iiasa.ac.at/Research/LUC/External-World-soil-database/HTML/

Dear Professor,

I did this in the TERRSET using (INTERPOLATE, RECLASS, BREAK OUT, CROSS and OVERLAY tabs) and it can be done in GIS as well:

1. Reclassify each 3 maps using the soil texture triangle or table (is attached) to determine each class of % sand, % clay and % silt. For example: To create the first class of the sand map, values 80-100 are assigned to class 1 and values outside this range to Class 0.

2. Multiply the maps with the same class using RASTER CALCULATION to achieve the first soil texture class (ex. sand class1 * silt class1 * clay class1).

3. Combine all maps derived from step 2 using RASTER CALCULATION. Notice that you may not have all 10 texture classes in your final map.

4. Label classes of final map nominally using properties/symbology.

I think all of these steps can be implemented through a logical and conditional query using soil texture table in RASTER CALCULATOR. But I do not know how to write the formula.

soil texture table.

Hope this will helpful

Dear Miss Abdolalizadeh

Thanks for your valuable solution.

regards

In SAGA GIS , you can easily do this. Just search for the soil texture module and then input either txt or raster of clay, silt and sand and the run. Options can be adjusted to what you want.

easily you can use SAGA GIS , soil analysis

Dear Sir Ataollah Ebrahimi,

As my opinion, if we can calculate the number that represent soil textural classes coming from the computed number based on our sand, silt, clay percent, we can import the table consisting of that number and then create soil textural classes based on that number.

For example,

Textural Classes : Min Max

Sand : 0.226 0.364608

Loamy Sand : 0.365 0.58328

Sandy Loam : 0.607 0.815

Loam : 0.828 1.129

Silty Loam : 0.848 1.160304

All green highlight cells in following jpg are the number based on sand, silt, clay percentage

You can download calculated excel file at following link

https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/?cid=nrcs142p2_054167

Sand, Silt, Clay percent range to soil textural classes should be referenced to Table 4 at following link

http://www.fao.org/tempref/FI/CDrom/FAO_Training/FAO_Training/General/x6706e/x6706e06.htm

Suggestion me, please.

I also doing soil textural classes map in arcMap.

Htein Linn

Hi Mr Linn. Many thanks for the suggestion about the FAO website Table 4.

But I found that it seems the table 4 is not correct for some soil types, e.g. Silt Loam, see the figure.

Maybe this package in R would help: https://cran.r-project.org/web/packages/soiltexture/index.html