Geospatial Analysis

Required: input and overlay polygon layers, explicit source and metric target CRS, new output directory and execution budget. Output: result GeoJSON, measured summary JSON, replay and provenance manifest.

HOLD: Missing inputs or failed contract gates. Prepared OMH routing is not execution or approval.

Why This Exists

Polygon computations can return plausible but wrong numbers when CRS, coordinate units or geometry are invalid. This skill couples fail-closed checks to a runnable optional overlay producer and inspectable replay artifacts.

First Steps

• Read toolkit/README.md and references/execution-and-qa.md before executing toolkit/scripts/analyze.py; installation and skill discovery never run it.
• Confirm the two layers, explicit EPSG declarations, study extent, projected metre CRS, output directory and finite host timeout; never guess a missing CRS. The helper reads GeoJSON only: for a shapefile, GeoPackage or KML ask for a GeoJSON export with the CRS stated, or offer a separately approved conversion (for example ogr2ogr).
• Use the original synthetic rectangle fixture only for backend QA; do not describe it as a public flood, facility or site-suitability finding.

Contract: references/full-contract.md, loaded before analysis. Procedure: references/procedure.md. These are working methods, not an OMH runtime operation.

Safety Rules