# Reference Reconstruction

The August 26, 2026 reference event is represented as a distinct scenario, `S0 - August 26 Reference Reconstruction`.

The reference volume is stored separately from the what-if lake-volume controls as `referenceReleaseMillionM3: 100`. The value follows Geopera's published reconstruction, which reports an approximately 100 million cubic metre event with substantial uncertainty.

The public showcase does not redistribute Geopera's CC BY-NC derived rasters, Vantor imagery, Planet imagery, Source Cooperative Planet Crisis Response imagery, trimline measurements, or hydraulic model outputs. Instead, S0 is a representative reconstruction envelope over the real Bhote Koshi / Trishuli corridor, classified as synthetic/representative and tied to the published reference scale.

Journey annotations combine modeled replay offsets such as `T+14 min` and `T+84 min` with real evidence acquisition windows from the Planet/Source Cooperative STAC catalog. The acquisition times identify when satellite scenes were collected; they are not observed flood-arrival timestamps.

The 2-5 Mm3 controls in the What-If Lab represent future barrier-lake scenarios only. They are not used to describe the August 26 event.

Calibration status: based on published reconstruction; direct observed validation layer is not redistributed. IoU, precision, recall, arrival-time error, stage residual, and velocity residual are therefore not reported.