AfA480: 2004 Climate Change Fluvial Flood Depth Grids for England

2004 modelled fluvial flood depth data for England, created using the JFlow hydrodynamic model on a 5x5m grid. The data provides a high-level sensitivity analysis for a 20% increase in peak flows, representing both 1% and 0.1% annual chance flood events. It was produced to fill gaps in detailed local modelling for spatial planning and defines Flood Zone extents.

Use Cases

• High-level flood zone definition for spatial planning based on modelled flood extents.
• Sensitivity analysis of climate change effects on fluvial flooding using a 20% peak flow increase scenario.
• Strategic flood risk assessment at a regional scale where detailed local models are unavailable.

Strengths

• High spatial resolution from a 5x5m grid produced by a two-dimensional hydrodynamic model (JFlow).
• Nationwide coverage for England, providing a consistent baseline from 2004.
• Explicit modelling of a climate change scenario with a defined 20% increase in peak flows.

Limitations

• The dataset has not been updated since its creation in 2004, and climate change allowances have since changed.
• Explicit warnings state it is not suitable for property-level assessment or detailed decision-making.
• Metadata completeness is low, with no information on row count, specific columns, file size, or license.

Provenance

Source

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

Collection Method

Produced as a by-product of the 2004 generalised modelling project using the JFlow two-dimensional hydrodynamic model.

Time Range

2004 (modelling date).

Freshness

Last updated metadata dates: 2026-07-06 (future date suggests system placeholder). The underlying data is from 2004.

Geography

England, distributed in 100x100km tiles based on Ordnance Survey National Grid references (e.g., TL, TA).