Sen2GF3Floods: A Novel Multi-Source Remote Sensing Dataset for Flood Mapping

Sen2GF3Floods is a newly developed multi-source remote sensing dataset designed to strike a balance among data volume, annotation accuracy, and labeling efficiency. It is the first dataset to combine pre-disaster Sentinel-2 optical imagery with post-disaster Gaofen-3 (GF-3) synthetic aperture radar (SAR) data. The final dataset comprises 21,483 standardized samples, capturing nine significant flood events with high annotation quality.The dataset contains six spectral bands: four from Sentinel-2—red (Band 4), green (Band 3), blue (Band 2), and near-infrared (Band 8)—and two SAR bands from GF-3, specifically HH and HV polarizations. All bands are resampled to a uniform spatial resolution of 10 meters to ensure consistency across data sources.The dataset directory is organized into three main folders: sentinel2, gaofen3, and label. The Sentinel2 folder contains pre-disaster optical imagery acquired from Sentinel-2, while the gaofen3 folder includes post-disaster SAR imagery collected by Gaofen-3. The label folder provides the corresponding pixel-level annotation maps indicating flooded and non-flooded regions, ensuring clear spatial alignment with the input image pairs.