QL-2026-01 Coverage of evidence, Google Flood Hub: pre-registered protocol v1.8

Pre-registered protocol for an independent evaluation asking how many people live in reach of a river forecast whose accuracy has never been published. The study reanalyses the developer's own released per-gauge metrics, weighted by the population exposed behind each forecast point, and stratified by settlement mapping density so the answer can be read separately for well mapped and thinly mapped ground. This study makes no claim about the model's accuracy anywhere. The absence of a published metric is not evidence of poor skill, and any reader who comes away thinking that unmeasured means unreliable has been misled rather than informed. Status at deposit: no metric value has been read. The protocol, the basin frame of 230,028 African HydroBASINS level-12 units, the population weights, and all five strata that do not require a metric value were built blind, before the outcome was reachable. The analysis has not been run. Protocol v1.8, sha256 ea0a1ac42f31fd0919f01a82d358e6dda152e79f79fe16f250599b9799664e95. Amendments are appended to section 11 and the frozen text above it is never edited, so every version remains verifiable at its own git tag, v1.0 through v1.8. Version 1.0 hashes to 52ed62354fe58577c77661de5d20dc92a2991db84ad126d92c375e245efb71da. The deposit contains the protocol, its hash file, its OpenTimestamps proof, and a full archive of the repository, which carries the append-only decisions log and run log. Those logs record judgement calls, bugs, and deviations as they happened, including a self-reported period during which the study's own structural-blinding guard was inert, and a population-surface disagreement of roughly three and a half times in sparsely mapped basins that constrains how the results may be reported. Input data is not included, because it is not ours to redistribute and runs to hundreds of megabytes. Every input is re-fetchable from the URL and sha256 recorded in the manifest inside the archive. Anchoring and its limits. The protocol hash is stamped into the Bitcoin blockchain via OpenTimestamps, and the proof is included as PROTOCOL.md.ots. The full repository history is archived at Software Heritage as snapshot swh:1:snp:5918a1abf7ffa5d946009a89a9c8a6be4fa1eed5. An anchor made today certifies today, so the externally verifiable date for this pre-registration is 2026-08-06, and the earlier freeze date of 2026-08-04 recorded against protocol v1.0 rests on the repository's own record and should be read as a claim rather than as an attested fact. The ordering the study depends on is unaffected, because the anchor still falls before any metric value has been read.