DEMIX GIS Database Version 3.5

This was developed for a forthcoming paper.  A reference will be posted here when it is published.

This database supports the work of the Digital Elevation Model Intercomparison eXperiment (DEMIX) working group (Strobl and others, 2021; Guth and others, 2021; Bielski and others, 2024).  The four files have the database tables in CSV format.

•  Difference distributions for elevation, slope, and surface roughness.  The provides continuity with \cite{BielskiOthers2024, GuthOthers2024}; for readers who want, it has the statistics like RMSE and LE90 for elevation and two LSPs, as well as the signed mean and median differences.
•  FUV for a mixed suite of LSPs chosen to sample the full range of LSPs calculated from DEMs.  These provide a better rankings of the test DEMs, and provides an estimate of the robustness of LSPs and suggest that some should be used with caution.
•  FUV for the partial derivatives used for slope, aspect, and curvature.
•  FUV for the suite of integrated curvature measures (Minar and others, 2020. 

This version adds to CopDEM, ALOS AW3D30, and FABDEM:

• FathomDEM (Uhe and others, 2025)
•  EDTM 1.1 (https://s3.eu-central-1.wasabisys.com/openlandmap/dtm/dtm.bareearth_ensemble_p10_30m_s_2018_go_epsg4326_v20230221.tif, https://doi.org/10.5281/zenodo.7676373)
• GEDTM 1.2—this is the best version of 1.2 (there are at least two others,which have no scaling for the elevations) (https://s3.opengeohub.org/global/dtm/v1.2/gedtm_rf_m_30m_s_20060101_20151231_go_epsg.4326.3855_v1.2.tif
• GEDTM 1.1—this has 0.9” spacing https://s3.opengeohub.org/global/edtm/gedtm_rf_m_30m_s_20060101_20151231_go_epsg.4326.3855_v20250611.tif, https://doi.org/10.5281/zenodo.15689805
• GEDTM v 0—this has 0.9” spacing https://s3.opengeohub.org/global/edtm/legendtm_rf_30m_m_s_20000101_20231231_go_epsg.4326_v20250130.tif, https://doi.org/10.5281/zenodo.14900181

The database contains 1381 tiles, about 10x10 km, in 140 areas.  The tiles are based on the local projected grid, a change from earlier versions of the DEMIX database which used geographic outlines.

It does not consider the low altitude coastal DEMs; for those use version 3 (https://zenodo.org/records/13331458 ).

References:

Bielski, C.; López-Vázquez, C.; Grohmann, C.H.; Guth. P.L.; Hawker, L.; Gesch, D.; Trevisani, S.; Herrera-Cruz, V.; Riazanoff, S.; Corseaux, A.; Reuter, H.; Strobl, P., 2024. Novel approach for ranking DEMs: Copernicus DEM improves one arc second open global topography. IEEE Transactions on Geoscience & Remote Sensing.  vol. 62, pp. 1-22, 2024, Art no. 4503922, https://doi.org/10.1109/TGRS.2024.3368015

Guth, P.L.; Trevisani, S.; Grohmann, C.H.; Lindsay, J.; Gesch, D.; Hawker, L.; Bielski, C. Ranking of 10 Global One-Arc-Second DEMs Reveals Limitations in Terrain Morphology Representation. Remote Sens. 2024, 16, 3273. https://doi.org/10.3390/rs16173273

Guth, P.L.; Van Niekerk, A.; Grohmann, C.H.; Muller, J.-P.; Hawker, L.; Florinsky, I.V.; Gesch, D.; Reuter, H.I.; Herrera-Cruz, V.; Riazanoff, S.; López-Vázquez, C.; Carabajal, C.C.; Albinet, C.; Strobl, P. Digital Elevation Models: Terminology and Definitions. Remote Sens. 2021, 13, 3581. https://doi.org/10.3390/rs13183581

Minár, J., Ian S. Evans, Marián Jenčo, 2020, A comprehensive system of definitions of land surface (topographic) curvatures, with implications for their application in geoscience modelling and prediction, Earth-Science Reviews, Volume 211, 103414, ISSN 0012-8252, https://doi.org/10.1016/j.earscirev.2020.103414

Strobl, P.A.; Bielski, C.; Guth, P.L.; Grohmann, C.H.; Muller, J.P.; López-Vázquez, C.; Gesch, D.B.; Amatulli, G.; Riazanoff, S.; Carabajal, C. The Digital Elevation Model Intercomparison eXperiment DEMIX, a community based approach at global DEM benchmarking. Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci. 2021, XLIII-B4-2021, 395–400. https://doi.org/10.5194/isprs-archives-XLIII-B4-2021-395-2021

Uhe, P., Lucas, C., Hawker, L., Brine, M., Wilkinson, H., Cooper, A., & Sampson, C. (2025). FathomDEM: an improved global terrain map using a hybrid vision transformer model. Environmental Research Letters, 20(3), 034002.  https://doi.org/10.1088/1748-9326/ada972