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 for a 20% increase in peak flows, covering both 1% and 0.1% annual chance flood scenarios for specific Ordnance Survey grid squares. It was produced to fill gaps in detailed local data for defining flood zones for spatial planning.

Use Cases

• High-level flood zone definition for spatial planning based on modelled extents.
• Sensitivity analysis of potential climate change effects using a 20% peak flow increase scenario.
• Regional-scale flood risk screening using 5x5m grid depth data.

Strengths

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

Limitations

• Dataset has not been updated since its creation in 2004, and climate change allowances have since changed.
• The source descriptions contain a conflict regarding the annual chance of flooding, citing both 1% and 0.1% scenarios.
• Metadata is incomplete, with unknown row counts, column details, and specific license information.

Provenance

Source

Environment Agency (UK)

Collection Method

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

Time Range

2004

Freshness

Last updated metadata dates are from 2026, but the underlying data is from 2004 and is explicitly stated as not updated.

Geography

England, distributed by 100x100km Ordnance Survey National Grid references (e.g., NY, NT).