AfA480: 2004 Fluvial Flood Depth Climate Change Difference Grid

The 2004 generalised modelling project produced a depth difference grid showing the change in modelled fluvial flood depths under a 20% increase in peak flows, representing a climate change scenario. This data, generated using the JFlow hydrodynamic model, covers a 0.1% annual chance flood event on a 5x5 meter grid for specific 100x100km Ordnance Survey grid squares in England. Its primary purpose was to fill gaps in detailed local data to help define Flood Zones for spatial planning.

Use Cases

• High-level flood zone definition for spatial planning based on modelled climate change impacts.
• Comparative analysis of baseline vs. climate-adjusted flood depths for specific grid references.
• Assessment of historical climate change modeling approaches in flood risk management.

Strengths

• Provides a consistent, nationwide 5x5m grid resolution for the modelled data.
• Explicitly models a specific climate change scenario (20% increase in peak flows).
• Produced using a named, two-dimensional hydrodynamic model (JFlow).

Limitations

• The dataset is outdated, created in 2004 with climate change allowances that are no longer current.
• Data is not suitable for property-level assessment or detailed site-specific flood risk studies.
• Metadata for size, row count, license, and specific columns is missing from all sources.

Provenance

Source

Environment Agency (UK), via the Approval for Access (AfA) product AfA480.

Collection Method

Generated as a by-product of a generalised modelling project using the JFlow hydrodynamic model.

Time Range

2004

Freshness

Metadata last updated July 2026, but the underlying data is from 2004 and has not been updated.

Geography

Specific 100x100km Ordnance Survey National Grid squares (e.g., SO, NT) within England.