Japan 250-meter Grid Hazard-Zone and Population Exposure Dataset: Hazard Areal Coverage and Estimated Exposed Population

Overview This dataset integrates hazard map raster tiles provided by the Geospatial Information Authority of Japan (GSI) with 250-meter population grid (5th-mesh) data from the 2020 Population Census (e-Stat). This dataset includes multiple official hazard-zone types and reports, for each 250-meter grid cell across Japan, the hazard-zone areal coverage ratio and the estimated population exposed to the corresponding hazard-zone type. Hazard tiles were obtained by modifying the program used in the Hazard Information Outline API (https://doi.org/10.1109/KST65016.2025.11003278). The hazard map raster tiles are based on data retrieved on 31 January 2026. Note that GSI hazard map open data only cover designated rivers and regions and therefore do not provide nationwide completeness. The hazard-zone types in this dataset are provided as separate indicators. The dataset should not be interpreted as a simultaneous, compound, or cumulative multi-hazard risk assessment. Detailed documentation in Japanese:https://note.com/utsuken_tokai/n/n088529043f99 USE CASES Overview-level municipal disaster management and hazard assessment GIS-based visualization of multiple hazard-zone layers and population exposure patterns Academic research in disaster risk, urban planning, and geography Preliminary analysis of elderly-population vulnerability Educational materials for geography and disaster risk reduction University lectures and community disaster-preparedness workshops Note: This dataset is an aggregated estimation derived from zoom‑15 hazard tiles converted into 250 m grid cells. It is not suitable for precise disaster-risk evaluation, evacuation decision-making, administrative judgment, or operational vulnerability assessments. HAZARD INFORMATION Hazard information is generated using a modified version of the program used in the Hazard Information Outline API (https://doi.org/10.1109/KST65016.2025.11003278), retrieving raster tiles (zoom level 15) from the Hazard Map Open Data provided by the Geospatial Information Authority of Japan (GSI). Please note that the GSI hazard map tiles cover only designated regions and rivers, and therefore do not represent nationwide coverage for all hazard types. A value of zero for a hazard-zone indicator means that no corresponding hazard-positive pixel was identified in the available hazard map tiles for that grid cell. It should not be interpreted as definitive absence of hazard. Population exposure calculations use the 250-meter grid cell population data from the 2020 Population Census (250-meter mesh, JGD2011), as published on e-Stat on 9 October 2025. Mesh units classified as “suppressed mesh” (秘匿メッシュ) in the census are excluded from hazard aggregation and exposure calculations. Hazard raster tiles were retrieved from the GSI Hazard Map Open Data on 31 January 2026. Hazard categories included in this dataset Hydro-meteorological and tsunami hazards Flood inundation (L1: design flood scale) Flood inundation (L2: assumed maximum scale) Areas where buildings are at high risk of collapse due to flooding: flood flow Areas where buildings are at high risk of collapse due to flooding: riverbank erosion Storm surge (hightide) inundation (assumed maximum scale) Tsunami inundation (assumed maximum scale) Landslide hazards Debris flow Steep slope failure Landslide Union of the above three categories (Landslide warning areas and special warning areas are not distinguished.) COLUMNS Columns Description Basic Information KEY_CODE — 250-meter (5th-mesh) grid cell code. lon — Longitude of the grid center (JGD2011, 6 decimal places). lat — Latitude of the grid center (JGD2011, 6 decimal places). Grid cell center coordinates (lon, lat) are computed from the standard regional mesh code (KEY_CODE). Flood, storm surge and tsunami hazards Each hazard type includes three variables: *_inclusion —Indicates whether any hazard pixels exist within the mesh.1 = at least one pixel is classified in the hazard zone; 0 = no corresponding hazard-positive pixel was identified in the available hazard map tiles. *_ratio —Proportion of hazard pixels:hazard pixel count / total pixel count in the grid cell.Note: Pixel count varies by latitude; small geometric errors may remain. *_exposure —Estimated exposed population:grid cell population × ratio. By convention, when a grid cell contains no hazard pixels, *_ratio and *_exposure are set to 0. Variables: flood_l1 — Maximum flood inundation depth level (L1: planned scale, 0–8). flood_l2 — Maximum flood inundation depth level (L2: maximum assumed scale, 0–8). hightide — Maximum storm surge inundation depth level (0–8). tsunami — Maximum tsunami inundation depth level (0–8). Corresponding ratio/exposure variables: flood_l1_inclusion / ratio / exposure flood_l2_inclusion / ratio / exposure hightide_inclusion / ratio / exposure tsunami_inclusion / ratio / exposure Areas where buildings are at high risk of collapse due to flooding: kaokutoukai_hanran_inclusion / ratio / exposure — Flooding flow. kaokutoukai_kagan_inclusion / ratio / exposure — Bank erosion. Landslide-Related Hazards: For landslide hazards, warning zones and special warning zones are not distinguished. If any pixel in the mesh is included in either category, the mesh is flagged as inclusion = 1. dosekiryukeikaikuiki_inclusion / ratio / exposure — Debris flow. kyukeishakeikaikuiki_inclusion / ratio / exposure — Steep-slope failure. jisuberikeikaikuiki_inclusion / ratio / exposure — Landslide. Union variable: doshasaigai_union_inclusion / ratio / exposure —1 if any of the above three hazard types are present. Inundation Depth Classes (based on GSI Open data legend) For flood, storm surge, and tsunami hazards, the maximum value within each grid cell is used as the representative inundation depth class. Based on the official GSI hazard legend: Value Meaning (Depth) 8 ≥ 20.0 m 7 10.0 – 20.0 m 6 5.0 – 10.0 m 5 3.0 – 5.0 m 4 0.5 – 3.0 m 3 0.5 – 1.0 m 2 ≤ 0.5 m 1 ≤ 0.3 m 0 Not applicable Population Data Population data are sourced from: e‑Stat Population Census 2020 (250 m grid cells, JGD2011; updated 2025‑10‑09) Population-suppressed (“secret”) meshes in the census data are excluded from hazard aggregation and exposure estimation. Notes and Disclaimer This dataset is derived from multiple open data sources (GSI hazard maps and 250 m population census). Due to limitations in the source data, small discrepancies or inconsistencies may remain. The dataset provides estimated values and is not intended for operational decision-making such as emergency management, evacuation planning, administrative judgment, or detailed vulnerability assessment.Although care has been taken to ensure accuracy, the authors assume no responsibility for any damages resulting from use of this dataset. Data Sources Hazard layers are derived from GSI Hazard Map Open Data (XYZ “GSI Tiles”), with attribution provided per GSI tile terms,https://disaportal.gsi.go.jp/hazardmapportal/hazardmap/copyright/opendata.html Population counts come from the 2020 Population Census 5th‑mesh statistics (Statistics Bureau of Japan; accessed via e‑Stat / G‑space Center) under the dataset’s specific terms,https://www.e-stat.go.jp/gis/statmap-search?page=1&type=1&toukeiCode=00200521&toukeiYear=2020&aggregateUnit=Q&serveyId=Q002005112020&statsId=T001102&datum=2000&by_prefecture_flg=1 National Land Numerical Information: Standard Regional Mesh Codes License This dataset is released under the CC BY 4.0 license.Please cite the Zenodo DOI when using the dataset in publications or research outputs.