2004 Fluvial Flood Depth Climate Change Difference Grid for England

A 2004 dataset provides a 5x5 meter grid showing the difference in modelled fluvial flood depths between baseline conditions and a climate change scenario with a 20% increase in peak flows. It was generated using the JFlow two-dimensional hydrodynamic model as part of a generalized modelling project to define flood zone extents for spatial planning in England. The data covers specific 100x100km Ordnance Survey grid tiles (NZ, NU) and represents both the 1% (1 in 100) and 0.1% (1 in 1000) annual chance flood events.

Use Cases

• Assessing potential changes in flood inundation extent for spatial planning based on a 2004 climate change scenario.
• Comparing baseline and climate-adjusted flood depths at a 5-meter resolution for broad regional analysis.
• Identifying areas where generalized 2004 modelling data suggests increased flood risk due to a 20% peak flow increase.

Strengths

• Provides a high-resolution (5x5m) spatial comparison of flood depths under two scenarios.
• Based on outputs from a specified two-dimensional hydrodynamic model (JFlow).
• Covers multiple annual probability flood events (1% and 0.1%).

Limitations

• The dataset is outdated (from 2004) and climate change allowances have since changed; it has not been updated.
• Explicitly not suitable for site-specific assessments, property-level decisions, or detailed flood risk studies.
• Metadata is incomplete regarding specific column names, row counts, license, and precise spatial coverage beyond grid references NZ and NU.

Provenance

Source

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

Collection Method

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

Time Range

2004

Freshness

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

Geography

England, specifically for the 100x100km Ordnance Survey National Grid references NZ and NU.