# EPISTEMIC_RISK_CLASSES.md
A registry of decision contexts that require an `epistemic_justification` before high-impact geospatial operations proceed. Use this alongside `JUSTIFICATION_SCHEMA.md` and the implementation blueprint in `IMPLEMENTATION_PLAN.md`.
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## Risk Classes
- **CRS_DATUM**
- **Trigger**: Reprojection or datum transformations that change spatial meaning.
- **Why**: Projection choice alters distances, areas, hydrologic realism.
- **Methodology**: `CRS.md`
- **RESAMPLING**
- **Trigger**: Raster resampling, resolution changes, or grid realignments.
- **Why**: Resampling encodes which signal (classification, gradient, smoothness) is preserved.
- **Methodology**: `RESAMPLING.md`
- **HYDROLOGY**
- **Trigger**: Conditioning, sink filling/breaching, flow routing, drainage adjustments.
- **Why**: Alters process truth about how water moves across the surface.
- **Methodology**: `HYDROLOGY.md`
- **AGGREGATION**
- **Trigger**: Statistical summarization that collapses distributions into a single value.
- **Why**: Privileges an interpretation (central tendency, extremes, dominant class).
- **Methodology**: `AGGREGATION.md`
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## Escalation Outcomes
- **Proceed**: Justification present and input hash matches.
- **Warn**: Justification present but stale (hash mismatch) – proceed with caution and emit a receipt.
- **Block**: High-risk tool without justification when policy marks it critical (see `IMPLEMENTATION_PLAN.md`).
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## References
- `JUSTIFICATION_SCHEMA.md` – schema for justification objects.
- `IMPLEMENTATION_PLAN.md` – operational plan for preflight, hashing, storage, and receipts.
