massomo/abscorrespondance

Australian Geographic Correspondence Table (ABS ASGS Edition 3)

A comprehensive correspondence table linking Australian geographic hierarchies (POA ↔ LGA ↔ SA2 ↔ Branch Catchments) built using real Australian Bureau of Statistics (ABS) data.

Dataset Description

This dataset provides complete spatial correspondence relationships between different levels of the Australian Statistical Geography Standard (ASGS) Edition 3, enabling accurate feature aggregation and geographic analysis across Australia.

What's Included

• Master Correspondence Table: 95,674 records linking POA, LGA, SA2, and HCF branch catchments
• Branch Catchments: 9 unique HCF service areas with 15km radius coverage
• Spatial Weights: Area-based intersection ratios for accurate data aggregation
• Geographic Coverage: Complete national coverage of Australian boundaries

Files

File	Records	Size	Description
master_correspondence_table.parquet	95,674	271KB	Main correspondence table (recommended)
master_correspondence_table.csv	95,674	11MB	Main correspondence table (CSV format)
branch_catchments.parquet	9	38KB	HCF branch service areas
branch_catchments.csv	9	38KB	HCF branch service areas (CSV format)

Schema

Master Correspondence Table

Column	Type	Description
poa_code	string	4-digit Postal Area code
poa_name	string	Postal Area name
lga_code	string	5-digit Local Government Area code
lga_name	string	Local Government Area name
sa2_code	string	9-digit Statistical Area Level 2 code
sa2_name	string	Statistical Area Level 2 name
branch_id	string	Unique branch identifier (null if >15km from any branch)
branch_name	string	HCF branch facility name (null if >15km from any branch)
branch_type	string	"Dental" or "Eyecare" (null if >15km from any branch)
branch_lat	float	Branch latitude (null if >15km from any branch)
branch_long	float	Branch longitude (null if >15km from any branch)
poa_to_lga_weight	float	Area-weighted intersection ratio (0-1)
lga_to_sa2_weight	float	Area-weighted intersection ratio (0-1)
catchment_overlap_pct	float	% of catchment overlapping with area (0 if >15km)
distance_to_branch_km	float	Distance from area centroid to nearest branch (0 if >15km)
record_type	string	"geographic_only" or "master_correspondence"

Geographic Coverage

• 2,644 POA boundaries (Postal Areas) - ABS 2021 data
• 566 LGA boundaries (Local Government Areas) - ABS 2022 data
• 2,473 SA2 boundaries (Statistical Area Level 2) - ABS 2021 data
• 9 HCF branch catchments (15km radius service areas)

Use Cases

Feature Aggregation

import pandas as pd

# Load correspondence table
corr = pd.read_parquet('master_correspondence_table.parquet')

# Aggregate postcode-level data to LGA level
postcode_data = pd.read_csv('your_postcode_data.csv')
lga_aggregated = postcode_data.merge(corr, left_on='postcode', right_on='poa_code') \
    .groupby('lga_code').agg({
        'population': 'sum',
        'income': lambda x: np.average(x, weights=corr.loc[x.index, 'poa_to_lga_weight'])
    })

Service Area Analysis

# Find all areas within HCF branch catchments
branch_areas = corr[corr['branch_id'].notna()]
coverage_by_branch = branch_areas.groupby('branch_name').agg({
    'sa2_code': 'count',
    'catchment_overlap_pct': 'mean'
})

Data Quality

• Spatial Accuracy: Built using official ABS ASGS Edition 3 boundaries
• Coverage: 100% coverage of Australian POA, LGA, and SA2 areas
• Validation: Comprehensive geometric and topological validation
• Weights: Area-based intersection calculations for precise aggregation

Source Data

• ABS ASGS Edition 3: Australian Statistical Geography Standard digital boundaries
• POA 2021: Postal Area boundaries (GDA2020 coordinate system)
• LGA 2022: Local Government Area boundaries (GDA2020 coordinate system)
• SA2 2021: Statistical Area Level 2 boundaries (GDA2020 coordinate system)

Methodology

1. Data Download: Automated download of official ABS shapefiles
2. Spatial Processing: Geometric intersection calculations using GeoPandas
3. Weight Calculation: Area-based ratios for accurate feature aggregation
4. Catchment Generation: 15km radius buffers in Australian Albers projection
5. Validation: Comprehensive quality checks and coverage analysis

License

This dataset is licensed under the MIT License. The underlying ABS data is available under Creative Commons Attribution 4.0 International License.

Citation

@dataset{hcf_abs_correspondence_2024,
  title={Australian Geographic Correspondence Table (ABS ASGS Edition 3)},
  author={HCF Data Science Team},
  year={2024},
  publisher={Hugging Face},
  url={https://huggingface.co/datasets/massomo/abscorrespondance}
}

Technical Details

• Built with: Python, GeoPandas, Shapely, PyProj
• Coordinate Systems: WGS84 (EPSG:4326) and Australian Albers (EPSG:3577)
• Processing: Spatial intersection, area calculation, distance analysis
• Export: Parquet and CSV formats with comprehensive metadata

Contact

For questions about this dataset or the underlying methodology, please refer to the source repository or open an issue on the project GitHub page.

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Generated using the Master Correspondence Table Builder - a modern Python replacement for legacy SAS Enterprise Guide geographic workflows.