---
name: "geopandas-spatial-polygon-overlay"
description: "Perform spatial operations, coordinate reference system (CRS) projections, and geometric joins."
metadata:
  author: "GeoPandas"
  version: "1.0.0"
  runtime_compatibility:
    - "codex"
    - "claude-code"
    - "cursor"
    - "windsurf"
triggers:
  - "spatial join geopandas"
  - "reproject crs geopandas"
  - "read geoparquet file"
permissions:
  fs_read: true
  fs_write: "workspace"
  shell_exec: false
  net_access: false
---

# GeoPandas Spatial Joins & Polygon Overlays

Analyzes spatial datasets using GeoPandas: loading Shapefiles/GeoJSON/GeoParquet, setting and transforming CRS (EPSG:4326 to EPSG:3857), executing spatial joins (sjoin), and computing polygon intersections.

## When to Invoke
Invoke this skill whenever you need to:
- spatial join geopandas
- reproject crs geopandas
- read geoparquet file

## Execution SOP & Rules
1. Load data: gdf = gpd.read_file('boundaries.geojson') or gpd.read_parquet('data.geoparquet').
2. Reproject CRS: gdf = gdf.to_crs(epsg=3857) before calculating distance or area metrics.
3. Perform spatial join: points_in_polys = gpd.sjoin(points_gdf, polys_gdf, how='inner', predicate='within').
4. Export results: points_in_polys.to_parquet('output.geoparquet').

## Verification Checklist
- Run local linting, syntax validation, and type-checks before reporting completion.
- Ensure all created or modified files adhere to workspace boundaries and avoid uncommitted secrets.
- Verify tests or build commands exit cleanly with return code 0.