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 dataset provides a high-level sensitivity analysis of climate change effects, assuming 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 sensitivity analysis of climate change impacts on flooding based on a 20% flow increase scenario.
• Defining extents of Flood Zones for spatial planning where detailed local models were unavailable in 2004.
• Strategic flood risk assessment at a regional scale using the 5x5m resolution depth grids.

Strengths

• Provides national coverage for England, though data is distributed in 100x100km tiles.
• Uses a specific two-dimensional hydrodynamic model (JFlow) to generate data at a 5x5m grid resolution.
• Based on a clearly defined climate change scenario of a 20% increase in peak flows.

Limitations

• Dataset has not been updated since 2004, and climate change allowances have since changed, reducing its accuracy for current assessments.
• Sources conflict on the annual chance of flooding, with descriptions for both 0.1% (1 in 1000) and 1% (1 in 100) events.
• Metadata completeness is low, with no information on row count, specific columns, file size, or license.

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 updated metadata dates are 2026-07-06, but the underlying data is from 2004 and explicitly noted as not updated.

Geography

England, distributed by 100x100km Ordnance Survey National Grid tiles (e.g., tile SU).