Identity and coverage
- Catalogue identifier
- res-01de4451-c684-5e12-bbae-12624e0e455d
- Persistent identifier
- 57723eed-8f89-4bec-8ab4-1acd12a34df1
- Resource version
- HDX metadata state observed 3 September 2026
- Publication date
- 31 August 2026
- Last updated
- 3 September 2026
- Metadata reviewed
- 3 September 2026
- Language
- English
- Geographic coverage
- Provider-defined assessment area in the Nepal event corridor, with municipal summaries for the intersecting analysis area.
- Bounding box (WGS 84)
- [84.52739332, 27.78286814, 85.56596468, 28.3460786]
- Temporal coverage
- 26 August 2025 to 28 August 2026; Mixed
- Themes
- Damage Proxy, Synthetic Aperture Radar, Buildings, Rapid Prioritization
Method and provenance
- Production method
- Sentinel-1 IW VV/VH backscatter observations from 26 August 2025 to 26 August 2026 defined a pre-event baseline. The 28 August 2026 acquisition was standardized by z-score; maximum absolute VV/VH anomaly was averaged with a normalized 50 m kernel and restricted to within 30 m of pre-event Overture building footprints. A K50 absolute z-score threshold of at least 1.60 defined the high-confidence layer, which was then visually reviewed and edited.
- Provenance
- Produced by REACH Initiative/IMPACT Initiatives from Sentinel-1 observations, Overture building footprints, and held-out Copernicus EMSR927 grading data; published through HDX.
- Validation
- Partially Validated
- Uncertainty
- Against held-out Copernicus damaged/destroyed observations, the provider reports 53.1% recall and 69.4% F1 for the automated threshold. The zero of 92 'possibly damaged' observations above threshold must not be interpreted as conventional precision or specificity because that class is not verified undamaged.
- Limitations
- The output is a backscatter-change proxy, not proof of structural damage. Signals can arise from debris, sediment, inundation, moisture, roughness, vegetation, clearance, or other change; damage can also be missed. Steep terrain and viewing geometry are important because dedicated radiometric terrain flattening was not applied.
Access and reuse
- Access
- Direct Open; open access route
- Licence
- Creative Commons Attribution (CC BY; version not specified); licence evidence
- Redistribution
- Permitted Under Stated Package Licence
- Catalogue status
- Reviewed
- Provider page
- Open authoritative resource page
Assets
Sentinel-1 damage screening by local administrative area — Nepal, version 3
Asset bounding box not stated. Parent resource coverage: Provider-defined assessment area in the Nepal event corridor, with municipal summaries for the intersecting analysis area.
Open asset Metadata assessed
Sentinel-1 high-confidence damage-screening features
WGS 84 bounding box: [84.52739332, 27.78738226, 85.38748879, 28.28104688]
Open asset Metadata assessed