External Sources
External Data-Source List
This list summarizes external data sources used in the global model, their licenses, and their source links. Details on how reclassified, corrected, combined, or pre-generated inputs are used in the model are provided in the input-data table.
| External data source | Summary | License | Source |
|---|---|---|---|
| Köppen-Geiger Global 1-km climate maps | Global climate-classification data used to organize surface conditions and regional characteristics according to terrain and climate. | CC-BY 4.0 | gloh2o.org |
| CHELSA-monthly | Monthly climate data from CHELSA V2.1. Precipitation and potential evapotranspiration are used as steady forcing. | CC0 1.0 | CHELSA-monthly |
| ERA5 post-processed daily statistics on single levels | Global reanalysis data used for daily precipitation, temperature, wind speed, surface pressure, relative humidity, and radiation in transient analysis. | CC-BY | Copernicus CDS |
| ISIMIP / CMIP6 GCM scenario inputs | Climate-scenario inputs used to compare future climate conditions in the global model. | ISIMIP Terms | ISIMIP |
| ALOS World 3D - 30m (AW3D30) | Global land-elevation data used as base information for the ground surface, terrain relief, and weathering-surface generation. | Commercial use allowed | JAXA EORC |
| GEBCO_2026 Grid | Global bathymetry grid used to define marine cells, water depths, and boundary conditions. | Public Domain | GEBCO |
| HydroSHEDS v1 ACC / ELV | Global river and hydro-terrain data. Accumulation area and elevation are used to organize river locations and bed elevations. | Commercial use allowed | HydroSHEDS |
| HydroLAKES | Global lake data used to organize lake extent and lake-surface information. | CC-BY 4.0 | HydroLAKES |
| GLOBathy | Global lake-bathymetry data used to organize lake-bed elevation and lake topography. | CC0 1.0 | GLOBathy |
| SoilGrids | Global soil data. Sand, silt and clay content and bulk density are connected to hydraulic-property classes for topsoil and cover layers. | CC-BY 4.0 | SoilGrids FAQ |
| USGS World Geologic Maps | World geologic maps reclassified into model geologic codes and used as bedrock conditions. | Public Domain | USGS |
| Global Land Cover and Land Use 2019 (GLCLUC2019) | Global land-use and land-cover data used for surface conditions such as forest, cropland, built-up areas, and water bodies. | CC-BY 4.0 | GLAD UMD |
| ESA CCI PFT 2020 | Global plant-functional-type data used to classify forest types and connect vegetation conditions to forest evapotranspiration. | No use restriction | ESA CCI |
| ETH Global Canopy Height 2020 | Global canopy-height data used for forest evapotranspiration and vegetation-parameter settings. | CC-BY 4.0 | ETH Research Collection |
| Crowther Global Tree Density | Global tree-density data used to set forest structure. | CC BY-ND 4.0 | Yale EliScholar |
| ISIMIP3 crop calendar | Crop calendar used to prepare crop coefficients and soil evaporation coefficients for FAO-56. | ISIMIP Terms | ISIMIP |
| GRDC-Caravan | River-discharge observation time series included in GRDC-Caravan. The model uses the Caravan dataset, not direct GRDC distribution. | CC-BY 4.0 | Caravan GitHub |
Note: License conditions follow the original data providers.
References
- Köppen-Geiger climate maps: Beck, H. E., Zimmermann, N. E., McVicar, T. R., Vergopolan, N., Berg, A., & Wood, E. F. (2018). Present and future Köppen-Geiger climate classification maps at 1-km resolution. Scientific Data, 5, 180214. https://doi.org/10.1038/sdata.2018.214
- CHELSA-monthly: Karger, D. N., Brun, P., & Zilker, F. (2025). CHELSA-monthly climate data at high resolution. EnviDat. https://www.doi.org/10.16904/envidat.686
- CHELSA V2.1 model: Karger, D. N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R. W., Zimmermann, N. E., Linder, H. P., & Kessler, M. (2017). Climatologies at high resolution for the earth's land surface areas. Scientific Data, 4, 170122. https://doi.org/10.1038/sdata.2017.122
- ERA5 daily statistics: Copernicus Climate Change Service. ERA5 post-processed daily statistics on single levels from 1940 to present. Copernicus Climate Data Store. https://doi.org/10.24381/cds.4991cf48
- WFDE5: Cucchi, M., Weedon, G. P., Amici, A., Bellouin, N., Lange, S., Müller Schmied, H., Hersbach, H., & Buontempo, C. (2020). WFDE5: bias-adjusted ERA5 reanalysis data for impact studies. Earth System Science Data, 12, 2097-2120. https://doi.org/10.5194/essd-12-2097-2020
- ISIMIP3BASD: Lange, S. (2019). Trend-preserving bias adjustment and statistical downscaling with ISIMIP3BASD (v1.0). Geoscientific Model Development, 12, 3055-3070. https://doi.org/10.5194/gmd-12-3055-2019
- W5E5: Lange, S. (2019). WFDE5 over land merged with ERA5 over the ocean (W5E5). Version 1.0. GFZ Data Services. https://doi.org/10.5880/pik.2019.023
- ISIMIP3BASD software: Lange, S. (2020). ISIMIP3BASD v2.4.1. Zenodo. https://doi.org/10.5281/zenodo.3898426
- HydroSHEDS: Lehner, B., Verdin, K., & Jarvis, A. (2008). New global hydrography derived from spaceborne elevation data. Eos, Transactions American Geophysical Union, 89(10), 93-94. https://doi.org/10.1029/2008EO100001
- HydroLAKES: Messager, M. L., Lehner, B., Grill, G., Nedeva, I., & Schmitt, O. (2016). Estimating the volume and age of water stored in global lakes using a geo-statistical approach. Nature Communications, 7, 13603. https://doi.org/10.1038/ncomms13603
- GLOBathy: Khazaei, B., Read, L. K., Casali, M., Sampson, K. R., & Yates, D. N. (2022). GLOBathy, the global lakes bathymetry dataset. Scientific Data, 9, 36. https://doi.org/10.1038/s41597-022-01132-9
- SoilGrids: Poggio, L., de Sousa, L. M., Batjes, N. H., Heuvelink, G. B. M., Kempen, B., Ribeiro, E., & Rossiter, D. (2021). SoilGrids 2.0: producing soil information for the globe with quantified spatial uncertainty. SOIL, 7, 217-240. https://doi.org/10.5194/soil-7-217-2021
- GRDC-Caravan: Kratzert, F., Nearing, G., Addor, N., Erickson, T., Gauch, M., Gilon, O., Gudmundsson, L., Hassidim, A., Klotz, D., Nevo, S., Shalev, G., & Matias, Y. (2023). Caravan - A global community dataset for large-sample hydrology. Scientific Data, 10, 61. https://doi.org/10.1038/s41597-023-01975-w
- Crowther Global Tree Density: Crowther, T. W., Glick, H. B., Covey, K. R., Bettigole, C., Maynard, D. S., Thomas, S. M., et al. (2015). Mapping tree density at a global scale. Nature, 525, 201-205. https://doi.org/10.1038/nature14967
- Forest evapotranspiration model: Inokoshi, S., Gomi, T., Chiu, C.-W., Onda, Y., Hashimoto, A., Zhang, Y., & Saitoh, T. M. (2023). A watershed-scale evapotranspiration model considering forest type, stand parameters, and climate factors. Forest Ecology and Management, 547, 121387. https://doi.org/10.1016/j.foreco.2023.121387
- Forest-floor evaporation model: Chiu, C.-W., Hashimoto, A., Inokoshi, S., Gomi, T., Onda, Y., & Sun, X. (2025). Developing a Structural Framework to Estimate Forest Floor Evapotranspiration With the Relative Yield Index (Ry). Ecohydrology, 18(7), e70125. https://doi.org/10.1002/eco.70125
- Snow and snowmelt analysis: 深沢壮騎・多田和広(2024)水循環モデルを用いた降雪地域における積雪・融雪期の再現性向上手法の検討.日本地下水学会2024年秋季講演会講演予稿集,講演番号07.
- FAO-56: Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. (1998). Crop evapotranspiration: Guidelines for computing crop water requirements. FAO Irrigation and Drainage Paper 56, FAO, Rome.
- Soil-water retention properties: Green, T. R., Constantz, J. E., & Freyberg, D. L. (1996). Upscaled soil-water retention using van Genuchten's function. Journal of Hydrologic Engineering, 1(3), 123-130.
- Mualem model: Mualem, Y. (1976). A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resources Research, 12(3), 513-522.
- van Genuchten model: van Genuchten, M. T. (1980). A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Science Society of America Journal, 44(5), 892-898.
- Rosetta3: Zhang, Y., & Schaap, M. G. (2017). Weighted recalibration of the Rosetta pedotransfer model with improved estimates of hydraulic parameter distributions and summary statistics (Rosetta3). Journal of Hydrology, 547, 39-53. https://doi.org/10.1016/j.jhydrol.2017.01.004
- unsatfit: Seki, K. (2022). unsatfit. https://sekika.github.io/unsatfit/
- SWRC Fit / unsatfit: Seki, K. (2024). SWRC Fit and unsatfit for parameter determination of unsaturated soil properties. 東洋大学紀要自然科学篇,68,57-79.
- Root water-uptake model: Feddes, R. A., Kowalik, P. J., & Zaradny, H. (1978). Simulation of field water use and crop yield. Simulation Monographs, Pudoc.
- Evaporation efficiency: Lehmann, P., Merlin, O., Gentine, P., & Or, D. (2018). Soil Texture Effects on Surface Resistance to Bare-Soil Evaporation. Geophysical Research Letters, 45(19), 10398-10405. https://doi.org/10.1029/2018GL078803
- GETFLOWS: Tosaka, H., Itoh, K., & Furuno, T. (2000). Fully coupled formulation of surface flow with 2-phase subsurface flow for hydrological simulation. Hydrological Processes, 14(3), 449-464.
- Model evaluation metric: Pool, S., Vis, M. J. P., & Seibert, J. (2018). Evaluating model performance: towards a non-parametric variant of the Kling-Gupta efficiency. Hydrological Sciences Journal, 63(13-14), 1941-1953. https://doi.org/10.1080/02626667.2018.1552002
Back to the Input-Data Table
See the input-data section of the technical overview page for how these sources are used as model inputs.