CCART Static Flood Susceptibility Index (FSI) for India (0.05°), Derived from Indo‑Floods Basin Validation

Overview This dataset provides the static Flood Susceptibility Index (FSI) v1.3 for India, produced within the CCART (Climate Change Assessment & Risk Toolkit) framework. FSI v1.3 is a basin‑wise, CHIRPS‑aligned, empirical flood susceptibility layer derived strictly from the publicly available INDOFLOODS dataset and HydroBASINS Level‑06 polygons. Unlike earlier interpolated versions, FSI v1.3 contains no smoothing, no IDW interpolation, and no proxy filling. It represents the true empirical IndoFloods domain, without artificial extension into ungauged regions. Values range from 0 to 1, where higher values indicate greater historical flood susceptibility within basins that contain IndoFloods gauges. Scientific Integrity Statement The publicly released INDOFLOODS dataset (Zenodo) does not include data for the upper Ganga and Brahmaputra basins. This is explicitly stated by the IndoFloods authors. As a result, FSI v1.3 shows NaN values in northern and northeastern India, including: Uttarakhand Himachal Pradesh Jammu & Kashmir Upper Ganga basin Upper Brahmaputra basin Arunachal Himalaya These regions are ungauged in the public IndoFloods release. FSI v1.3 preserves this truth and does not artificially fill or interpolate susceptibility. This version reflects CCART’s commitment to scientific honesty, transparency, and reproducibility. Purpose FSI v1.3 is a foundational empirical layer for: flood hazard modelling hazard–exposure–vulnerability integration district‑level diagnostics climate‑conditioned flood hazard (FSI × rainfall extremes) reproducible open‑science workflows CHIRPS‑aligned climate impact modelling It is fully aligned with CCART’s exposure grids and rainfall‑conditioned hazard engine. Data Characteristics Format: GeoTIFF (float32) Resolution: 0.05° CRS: EPSG:4326 Value range: 0–1 (NaN = ungauged basins) Spatial extent: India (CHIRPS‑aligned grid) Method: Basin‑wise aggregation of IndoFloods gauge‑level susceptibility Processing Steps (CCART) Compute gauge‑level FSI from IndoFloods catchment characteristics Spatially join gauges to HydroBASINS L06 polygons Aggregate FSI per basin (mean) Rasterise HYBAS polygons to CHIRPS 0.05° grid Min‑max rescale to 0–1 Mask outside India This workflow ensures full reproducibility and transparent scientific lineage. Version Notes v1.3 (this version): Rebuilt using strict empirical IndoFloods domain Removed all interpolation and proxy filling Basin‑wise HYBAS L06 aggregation CHIRPS‑aligned rasterisation Honest representation of ungauged northern basins v1.0 / v1.1 / v1.2 (previous versions): Used IDW interpolation and proxy basins Appeared to provide national coverage Did not reflect the true IndoFloods domain These earlier versions are retained for transparency but should be considered superseded by v1.3. Use and Citation Ketan (2026). CCART‑Floods: Static Flood Susceptibility Index (FSI) v1.3 — Basin‑wise, CHIRPS‑aligned, IndoFloods empirical domain. Zenodo. DOI: 10.5281/zenodo.19687893