%0 Generic
%A Helfenstein, Anatol
%A Mulder, Vera L.
%A Heuvelink, Gerard B.M.
%A Okx, Joop P.
%D 2021
%T Tier 4 maps of soil pH at 25 m resolution for the Netherlands
%U https://data.4tu.nl/articles/dataset/Tier_4_maps_of_soil_pH_at_25_m_resolution_for_the_Netherlands/16451739/1
%R 10.4121/16451739.v1
%K soil pH
%K digital soil map
%K Netherlands
%K Quantile Regression Forest
%K uncertainty
%K accuracy thresholds
%K quantiles
%K mean
%K median
%K high resolution
%X This dataset contains maps (GeoTIFFs) of soil pH of six standard depth layers for the Netherlands at 25 m resolution. The six standard depth layers are from 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100cm and 100-200cm. For each of these depth layers, there is a map of mean predictions, the 5th, 50th (median) and 95th quantile, as well as the 90% prediction interval (PI90 = 95th - 5th quantile) and a categorical map of the accuracy thresholds ("none", A, AA and AAA) based on GlobalSoilMap specifications for Tier 4 products. The accuracy thresholds were derived from the PI90, which is a measure of prediction uncertainty. All maps are based on predictions (mean) and estimations (quantiles) using a Quantile Regression Forest model, which was calibrated using 15338 soil pH measurements from the "Bodemkundig Informatie Systeem" (BIS) and 195 covariates (spatially explicit environmental variables of soil forming factors).
%I 4TU.ResearchData