AfA480: 2004 Fluvial Flood Depth Grids with Climate Change

2004 modelled fluvial flood depth data for England, created using the JFlow hydrodynamic model on a 5x5m grid. The dataset provides a high-level sensitivity analysis for climate change effects, simulating a 20% increase in peak flows for 0.1% and 1% annual chance flood events. It was produced to fill gaps in detailed local modelling for spatial planning but has not been updated since its creation.

Use Cases

• High-level flood zone definition for spatial planning based on generalized 2004 modelling.
• Sensitivity analysis of potential climate change impacts on fluvial flooding using a +20% peak flow scenario.
• Regional-scale flood risk screening where detailed local models are unavailable.

Strengths

• Nationwide coverage for England, providing a consistent baseline from 2004.
• High spatial resolution from a 5x5m grid generated by a two-dimensional hydrodynamic model (JFlow).
• Explicitly models a specific climate change scenario (20% increase in peak flows).

Limitations

• Data has not been updated since 2004, and climate change allowances have since changed.
• Conflicting information on the modelled annual chance (sources mention both 0.1% and 1%).
• The provider warns it is not suitable for property-level assessment or detailed decision-making.
• Metadata for size, row count, license, and specific columns is unavailable across all sources.

Provenance

Source

Environment Agency (UK)

Collection Method

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

Time Range

2004

Freshness

Last metadata update recorded as 2026-07-06, but the underlying data is from 2004 and explicitly stated as not updated.

Geography

England, specifically for the 100x100km Ordnance Survey National Grid reference SW (with data available for other grid references nationwide).