Historical Elevation Contours for New South Wales at 20m Resolution

20m Historical Contours are vector lines representing points of equal elevation relative to the Australian Height Datum (AHD). The contours were digitized from aerial photography and ortho images captured at scales of 1:25,000, 1:50,000, and 1:100,000, with processing completed between 2003 and 2017. The feature reliability dates of the original contours range from 1971 through to 2008.

Use Cases

• Modeling flood risk and water management based on elevation contours.
• Assessing natural hazard risk for emergency management planning.
• Supporting climate change adaptation studies based on terrain data.
• Defining maritime and administrative boundaries using elevation references.
• Enabling safe navigation for hydrographic, aeronautical, and road planning.

Strengths

• Contours were digitized from aerial photography at three specific scales: 1:25,000, 1:50,000, and 1:100,000.
• Processing was completed over a 14-year period from 2003 to 2017.
• Feature reliability dates span 37 years, from 1971 to 2008.

Limitations

• The dataset uses a spatial reference (WGS 84 ≈ GDA94) that may cause misalignment in GDA2020 environments.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

Spatial Services, a business unit of the Department of Customer Service NSW

Collection Method

Digitized from stereoscopic aerial photography or ortho image trace methods.

Time Range

1971 to 2008 (feature reliability), processed 2003-2017

Freshness

Data Update Frequency: Other

Geography

New South Wales, Australia