Soil Types – Mapping

Soil types in SCALGO Live

We use the following set of soil types in our analyses:

• Rocks and boulders
• Gravel
• Coarse sand
• Fine sand
• Coarse sand with clay
• Fine sand with clay
• Coarse clay with sand
• Fine clay with sand
• Clay
• Fine clay
• Very fine clay
• Silt
• Gyttja/peat
• Bedrock
• Glacier
• Water

We refer to the country specific information for detail on what soil type we assign to each class in the respective country's soil map. 

Note that not all countries have a soil type map available currently. Please contact us if you have questions about availability for your country.

The topsoil map

Following this mapping from national soil types to the soil typology above, we perform an adjustment of the soil type map to better reflect the type of soil we expect in the top layer of the soil. We use the land cover map and urban polygons for this mapping.  

The process of going from the generalized soil map to the topsoil map is as follows:

• If the land cover map says bare rock, the soil type map is set to bedrock, regardless of what it was before. 
• If the land cover map says snow/ice, the soil type is set to glacier, regardless of what it was before.
• If the land cover map says water, the soil type is set to water, regardless of what it was before.
• If the land cover map says railroad, the soil type is set gravel, regardless of what it was before.

Furthermore, some land cover types affect only some soil types, these rules are shown in the table below. The soil types not listed in the table are not affected at this step. The modifications based on unpaved road are made to ensure that infiltration rates are reduced due to the (natural) paving for soil types with high infiltration rates, but remains the same for soil types with low infiltration rates (where the lower infiltration rate in the original soil limits the infiltration rate through the paving material). The modifications based on the presence of vegetation (farmland, shallow vegetation and dense vegetation) are made to reflect that it's improbable to find vegetaion directly on e.g. gravel or bedrock, and therefore the topsoil is set to the most probable soil type found on top of that original soil type. 

Finally, we do the following inside urban areas, to reflect the probable human modifications to the original soils:

• Coarse sand, fine sand and coarse sand with clay are set to fine sand with clay.
• Clay, fine clay, very fine clay are set to fine clay with sand.

To see what data we use to define urban areas, please see the country specific information.

Both the final topsoil map and the original national soil map are available for you to see in SCALGO Live, but it is the topsoil map that is used in our analyses.