Holy Tree on QuShui, Tibet - Photo by Yongjiu Dai

A Global Depth to Bedrock Dataset for Earth System Modeling

Introduction | Data citation | Data download


We developed a global depth to bedrock (DTB) dataset for use in Earth System Models and other applications as well (Shangguan et al. 2017). It provides three variables, the absolute DTB in cm, the censored DTB in cm within 0¨C200 cm (here values equal to 200 cm indicate Ħ°deep as or deeper thanĦħ), and the occurrence of R horizon (bedrock) within 0¨C200 cm expressed as 0¨C1 probability values. This product is developed under an automated soil mapping framework as part of the SoilGrids system (Hengl, T. et al., 2017). This dataset is based on observations extracted from a global compilation of soil profile data (ca. 1,30,000 locations) and borehole data (ca. 1.6 million locations). Additional pseudo-observations generated by expert knowledge were added to fill in large sampling gaps. The model training points were then overlaid on a stack of 155 covariates including DEM-based hydrological and morphological derivatives, lithologic units, MODIS surface reflectance bands and vegetation indices derived from the MODIS land products. Global spatial prediction models were developed using random forest and Gradient Boosting Tree algorithms. The final predictions were generated at the spatial resolution of 250 m as an ensemble prediction of the two independently fitted models. The dataset can be also aggregate to a lower resolution (1km and 10km).

The documentation of the dataset can be downloaded here, including readme file and the data citation paper.

Data citation

Shangguan, W., Hengl, T., de Jesus, J.M., Yuan, H. and Dai, Y., 2017. Mapping the global depth to bedrock for land surface modeling. Journal of Advances in Modeling Earth Systems: Accepted.

Data download

The dataset in geotiff format can be downloaded in the following table.

We provided three versions with different resolution, i.e., 7.5 seconds (250m), 30 seconds (~1km) and 5 minutes (~10km).

The 5 minutes version:

No. Description Unit Geotiff file
1. absolute DTB cm BDTICM_M_10km_ll
2. censored DTB cm BDRICM_M_10km_ll
3. occurrence of R horizon % BDRLOG_M_10km_ll

The 30 seconds version:

No. Description Unit Geotiff file
1. absolute DTB cm BDTICM_M_1km_ll
2. censored DTB cm BDRICM_M_1km_ll
3. occurrence of R horizon % BDRLOG_M_1km_ll

The 7.5 seconds version:

No. Description Unit Geotiff file
1. absolute DTB cm BDTICM_M_250m_ll
2. censored DTB cm BDRICM_M_250m_ll
3. occurrence of R horizon % BDRLOG_M_250m_ll