| Name | Nationwide Probabilistic Flood Discharge Dataset |
| Abbreviation | d4Flood |
| DOI | doi:10.20783/DIAS.672 |
| Metadata Identifier | d4Flood20250917224458-DIAS20221121113753-en |
| Name | Takahiro Sayama |
|---|---|
| Organization | Disaster Prevention Research Institute, Kyoto University |
| Address | Gokasho, Uji, Kyoto, 6110011, Japan |
| TEL | 0774-38-4125 |
| sayama.takahiro.3u@kyoto-u.ac.jp |
| Name | Takahiro Sayama |
|---|---|
| Organization | Disaster Prevention Research Institute, Kyoto University |
| sayama.takahiro.3u@kyoto-u.ac.jp |
| Name | Takahiro Sayama |
|---|---|
| Organization | Disaster Prevention Research Institute, Kyoto University |
| sayama.takahiro.3u@kyoto-u.ac.jp |
This dataset provides estimates of flood peak discharges corresponding to various return periods across all river channels in Japan, including small- and medium-sized rivers, under present and future climate conditions (assuming global temperature increases of +2°C and +4°C).
From the 5-km mesh ensemble climate projections (d4PDF_5kmDDS_JP), approximately 3,000 to 5,000 heavy rainfall events were extracted for each region. These were used as input to the nationwide Rainfall-Runoff-Inundation (RRI) model, which represents Japan's topography at a 150-meter resolution. Flood discharges were simulated for all river reaches across Japan, and the results are compiled in this dataset.
At each river location, the top 72 discharge events were analyzed using extreme value statistics based on a non-annual (Peak-over-Threshold) series to estimate probabilistic flood peak discharges corresponding to arbitrary return periods of 10 years or more. In addition, the dataset includes the hydrographs and basin-averaged rainfall time series (hyetographs) of these 72 events used in the estimation, as well as the corresponding spatial rainfall distributions.
| North bound latitude | 50 |
| West bound longitude | 125 |
| Eastbound longitude | 150 |
| South bound latitude | 25 |
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file download : https://data.diasjp.net/dl/storages/filelist/dataset:672
The dataset can be freely used and modified for both commercial and non-commercial purposes, as long as proper citation is given.
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CC-BY 4.0 :
Creative Commons Attribution 4.0 International
This study used a nationwide probabilistic flood discharge dataset (d4Flood), created using the RRI model covering all of Japan.
If you plan to use this dataset for a conference presentation, paper, journal article, or report etc., please include acknowledgments referred to following examples. If the data provider describes examples of acknowledgments, include them as well.
" In this study, [Name of Dataset] provided by [Name of Data Provider] was utilized. This dataset was also collected and provided under the Data Integration and Analysis System (DIAS), which was developed and operated by a project supported by the Ministry of Education, Culture, Sports, Science and Technology. "
Chen, J., Sayama, T., Yamada, M., Tanaka, T., & Sugawara, Y. (2025). Projecting multiscale river flood changes across Japan at +2°C and +4°C climates. Earth's Future, 13, e2024EF005884. https://doi.org/10.1029/2024EF005884
Chen, J., Sayama, T., Yamada, M., & Sugawara, Y. (2025). Reducing the computational cost of process-based flood frequency estimation by extracting precipitation events from a large-ensemble climate dataset. Journal of Hydrology, 655, 132946. https://doi.org/10.1016/j.jhydrol.2025.132946
Sayama, T., Yamada, M., Yamakita, A. et al. Parameter regionalization of large-scale distributed rainfall–runoff models using a conditional probability method. Prog Earth Planet Sci 12, 17 (2025). https://doi.org/10.1186/s40645-025-00691-w