DOI: 10.5281/zenodo.17479135
title: Multi-scale Terrain Attributes and Sentinel-2 Bare Soil Composites for Digital Soil Mapping in Bavaria

description: This dataset contains a multi-band GeoTIFF raster file (COVARIATS_EPSG25832.tif) for the area of the German federal state Bavaria with 36 environmental covariates derived from digital elevation models (DEM) and Landsat satellite imagery. The dataset is designed for digital soil mapping applications, particularly for predicting soil organic carbon (SOC) content and other soil properties across Germany using machine learning approaches.

Spatial Reference System: ETRS89 / UTM zone 32N (EPSG:25832)

Data Format: GeoTIFF

Number of Bands: 36
description: Band Descriptions

The 36 bands are organized into four covariate categories. The terrain attributes have been derived using SAGA-GIS (System for Automated Geoscientific Analyses) accessed through the R package Rsagacmd (https://doi.org/10.32614/CRAN.package.Rsagacmd).

1. Digital Elevation Model (Band 1)





Band 1 - DEM: Sink-filled digital elevation model processed using SAGA-GIS ta_preprocessor fill_sinks_planchon_darboux_2001() function



2. Topographic Openness (Bands 2-11)

Topographic openness expresses the dominance (positive openness) or enclosure (negative openness) of a landscape location, derived using SAGA-GIS ta_lighting topographic_openness() function. Multiple radial limits were applied:





Band 2 - TPO_10: Topographic openness, radius 10 m




Band 3 - TPO_100: Topographic openness, radius 100 m




Band 4 - TPO_1000: Topographic openness, radius 1,000 m




Band 5 - TPO_10000: Topographic openness, radius 10,000 m




Band 6 - TPO_215: Topographic openness, radius 215 m




Band 7 - TPO_2154: Topographic openness, radius 2,154 m




Band 8 - TPO_222: Topographic openness, radius 222 m




Band 9 - TPO_46: Topographic openness, radius 46 m




Band 10 - TPO_464: Topographic openness, radius 464 m




Band 11 - TPO_4642: Topographic openness, radius 4,642 m



3. Slope (Band 12)





Band 12 - SLOPE: Terrain slope derived using SAGA-GIS ta_morphometry slope_aspect_curvature() function



4. Topographic Position Index (Bands 13-22)

The Topographic Position Index (TPI) characterizes the relative topographic position by calculating the elevation difference between a focal point and the mean elevation of the surrounding neighborhood, derived using SAGA-GIS ta_morphometry topographic_position_index_tpi() function. Multiple neighborhood radii were applied:





Band 13 - TPI_1000: TPI, radius 1,000 m




Band 14 - TPI_114: TPI, radius 114 m




Band 15 - TPI_147: TPI, radius 147 m




Band 16 - TPI_20: TPI, radius 20 m




Band 17 - TPI_271: TPI, radius 271 m




Band 18 - TPI_31: TPI, radius 31 m




Band 19 - TPI_419: TPI, radius 419 m




Band 20 - TPI_48: TPI, radius 48 m




Band 21 - TPI_647: TPI, radius 647 m




Band 22 - TPI_74: TPI, radius 74 m



5. Sentinel-2 Bare Soil Reflectance Composites (Bands 23-36)

Multi-temporal bare soil composites derived from Sentinel-2 imagery using the Soil Composite Mapping Processor (SCMaP) methodology. Bare soil pixels were identified using the combined NDVI and NBR index (PV+IR2) that optimizes the exclusion of photosynthetically active and non-photosynthetically active vegetation. The dataset contains 14 SRC bands:





Bands 23-29 (SRC_1 to SRC_7): Mean bare soil reflectance composites from Sentinel-2 bands




Bands 30-36 (SRC_8 to SRC_14): Albedo-normalized bare soil reflectance composites (normalized per scene using mean reflectance across all six reflective Sentinel-2 bands)



Additional methodological details are available in https://doi.org/10.1016/j.rse.2017.11.004 and https://dx.doi.org/10.1016/j.isprsjprs.2023.06.003.