This dataset was produced within the framework of the TEAPOTS virtual pilot project for Germany and is intended to support the analysis of areas where forest biomass is potentially transportable, taking into account terrain morphological conditions. The raster dataset represents terrain slope expressed as a percentage (%) for the territory of Germany. Slope values were derived from a Digital Elevation Model (DEM) based on the NASA Shuttle Radar Topography Mission (SRTM) with a spatial resolution of 30 m. The slope was calculated using the Horn algorithm with a 3 × 3 moving window, which estimates the terrain gradient by considering elevation differences between each pixel and its eight neighboring cells. The raster is projected in WGS 84 / UTM zone 31N (EPSG:32631) and retains the 30 m spatial resolution of the original DEM. Pixel values represent terrain slope expressed as percentage (%). This dataset is used as a topographic variable for assessing biomass accessibility and transportability within the spatial modelling activities carried out in the TEAPOTS project. The above-ground biomass (AGB) datasets associated with this analysis are available at the following links: AGB - 2023 - Part 1 of 3 AGB - 2023 - Part 2 of 3 AGB - 2023 - Part 3 of 3