DOI: 10.5281/zenodo.18137662
title: Global Flood Susceptibility Map (GFSM v1): A high resolution (30m) flood susceptibility dataset derived from multi-source geospatial data

description: The Global Flood Susceptibility Map (GFSM v1) is the first globally harmonized, high-resolution (30 m) flood susceptibility dataset derived using a machine learning framework. It identifies areas inherently prone to flooding based on landscape and environmental characteristics, independent of specific flood event frequency or magnitude.

This dataset was produced by training gradient-boosted tree model (XGBoost) on approximately 30.45 million samples extracted from ~17,000 grid tiles worldwide (~10,000 GBs of data, ~1.7 trillion pixels at 30m resolution). The models utilized global flood inundation data (Aqueduct Flood Hazard Maps) as training labels and incorporated nine flood conditioning factors:





Elevation




Slope




Aspect




Topographic Wetness Index (TWI)




Height Above Nearest Drainage (HAND)




Vegetation Index (NDVI)




Distance to water bodies




Distance to roads




Rainfall frequency



Dataset Specifications





Spatial Resolution: 30 meters (approx. 0.000269 degrees)




Geographic Coverage: Global (approx. 80°N to 60°S)




Coordinate Reference System (CRS): World Mercator (EPSG:3395)




File Format: GeoTIFF, tiled




Model Performance: Median ROC-AUC ~0.95 and F1-score ~0.90 across 192 regional units



Classification Scheme

The dataset provides susceptibility classes derived from the model's continuous probability output using equal-interval slicing. The pixel values correspond to the following categories:




Value
Class
Description
Probability Interval




0
No Data
Ocean, water bodies, or no coverage
-


1
Very Low
Minimal susceptibility
0.0 – 0.2


2
Low
Low susceptibility
0.2 – 0.4


3
Moderate
Moderate susceptibility
0.4 – 0.6


4
High
High susceptibility
0.6 – 0.8


5
Very High
Critical susceptibility
0.8 – 1.0




File Structure & Access

Due to the large data volume, the dataset is organized into regional compressed archives. Users should follow this workflow:





Download the Tile Index: Download GFSM_Tile_Index.zip first. This contains a GeoPackage (.gpkg) index.




Identify Your Region: Open the index in a GIS (QGIS or ArcGIS) to identify the specific Tile ID and the corresponding Regional Zip file for your area of interest.




Download Regional Data: Locate and download the specific archive (e.g., GFSM_N20W020.zip). These archives contain the GeoTIFF tiles and associated metadata JSON files.



Usage Notes





Application: GFSM v1 represents a baseline of flood susceptibility under present-day conditions. It is intended for exposure assessment, risk screening, and comparative spatial analysis.




Limitations: The map reflects the natural propensity of the landscape to flood. It does not account for man-made dynamic flood defenses (e.g., levees) or future climate change projections beyond the training data baseline.



Funding & Acknowledgments

This research was supported by Hong Kong Baptist University (HKBU) and utilized the Shaheen supercomputing resources at King Abdullah University of Science and Technology (KAUST).

Web Application:

The dataset is already available in Google Earth Engine as image collection. For details please check the Project GitHub repository at GFSM GitHub.Moreover, for quick visualization, the data is made available in the form of GEE web application, which can be accessed at GFSM Web App.