dd-l1-london-parks-count

Rerun

import geopandas as gpd
import json

def main():
    # Load the data
    gdf = gpd.read_file('london_parks.fgb')
    
    # Print info to inspect columns and CRS
    print("Columns:", gdf.columns.tolist())
    print("CRS:", gdf.crs)
    print("Head:\n", gdf.head())

    # Check for area column or calculate it
    # Area calculation depends on CRS. If it's WGS84 (epsg:4326), we need to project it first.
    
    # Determine if there is an 'area' column. If not, we'll calculate it.
    # Let's assume we need to calculate it in hectares.
    
    # Project to a suitable projected CRS if not already projected (e.g., British National Grid EPSG:27700)
    # Or just use a metric CRS for area calculations.
    if gdf.crs.is_geographic:
        # Project to British National Grid for accurate area in meters
        gdf_projected = gdf.to_crs(epsg=27700)
    else:
        gdf_projected = gdf.copy()

    # Calculate area in square meters, then convert to hectares (1 ha = 10,000 m^2)
    gdf_projected['area_ha'] = gdf_projected.geometry.area / 10000.0

    # Filter parks >= 1 hectare
    large_parks = gdf_projected[gdf_projected['area_ha'] >= 1.0].copy()

    # Count
    count = len(large_parks)

    # Total area in hectares
    total_area_ha = large_parks['area_ha'].sum()

    # Bounding box on WGS84
    # Project back to WGS84 to get bbox in degrees
    large_parks_wgs84 = large_parks.to_crs(epsg=4326)
    bounds = large_parks_wgs84.total_bounds  # [xmin, ymin, xmax, ymax]
    bbox_wgs84 = bounds.tolist()

    # Prepare output
    output = {
        "count": int(count),
        "total_area_ha": float(total_area_ha),
        "bbox_wgs84": bbox_wgs84
    }

    with open('parks_summary.json', 'w') as f:
        json.dump(output, f, indent=4)

    print("\nSummary:")
    print(output)

if __name__ == "__main__":
    main()