Contents
What is the additional uncertainty layer in SoilGrids?
The additional uncertainty layer displayed at soilgrids.org is the ratio between the inter-quantile range (90% prediction interval width) and the median : (Q0.95-Q0.05)/Q0.50. The values are multiplied by 10 in order to have integers and reduce the size of the datasets.
How can SoilGrids be used as a covariate?
For continents and regions, SoilGrids predictions can be used as a covariate to improve prediction of soil properties through e.g. regression-kriging. Simply download SoilGrids, run overlay with the point data and then use the SoilGrids layers as a covariate to predict or adjust the values of target variables locally.
How is SoilGrids used in global soil mapping?
SoilGrids TM (hereafter SoilGrids) is a system for global digital soil mapping that uses state-of-the-art machine learning methods to map the spatial distribution of soil properties across the globe. SoilGrids prediction models are fitted using over 230 000 soil profile observations from the WoSIS database and a series of environmental covariates.
Why are the layers set to different CRS?
I assumed that was because the layers were set to different CRS, but after right-clicking each layer and changing the CRS to WGS 84, nothing changes. What am I doing wrong here?
How are SoilGrids predictions made for six standard depth intervals?
SoilGrids predictions are made for the six standard depth intervals specified in the GlobalSoilMap IUSS working group and its specifications: SoilGrids maps have associated uncertainties as any product derived from a modelling approach. The prediction uncertainty is quantified by probability distributions.
Why are SoC stocks different in SoilGrids 2.0?
There are differences in the calculated stocks between the two versions of SoilGrids. These differences are due to different modelling approaches and different input data. The SOC stocks in SoilGrids version 2.0 were obtained with a calculate first interpolate later approach.