Integrated flooding
River and surface-water flood exposure read together on one band-aligned axis.
The question it answers
When we consider river overflow and surface-water flooding together, which assets carry the highest overall flood exposure?
Screening integrated flooding across a portfolio
- Combines the river and pluvial flood models into a single compound flood view.
- Keeps both hazards on the same band-aligned axis so the combined result is comparable across assets.
- Gives one flood band per asset, projected across SSP scenarios and horizons.
Inputs in, banded result out
The governed model combines the inputs below into a single banded, scenario-aware result, under formal version and change control.
Inputs
- River (fluvial) band
- Pluvial (surface-water) band
Governed model
Integrated flooding
Anchored to public, peer-reviewed climate science.
Version and change controlledOutputs
- Integrated flood band
- Component breakdown
- Portfolio roll-up
What goes in, and where it comes from
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River (fluvial) band
River flooding model
The fluvial component, already banded on the shared axis.
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Pluvial (surface-water) band
Pluvial flooding model
The surface-water component, on the same axis.
The futures we test
- Both component models are evaluated under the same scenario and horizon before they are combined.
- Components share a common band-aligned axis, so neither hazard is double-counted or drowned out.
- The integrated band reflects compound flood exposure, not the sum of independent events.
How the result is built
- Take the river and pluvial results for an asset under the same scenario and horizon.
- Combine them on the shared band-aligned axis into a single compound exposure score.
- Resolve to one integrated Low / Medium / High flood band.
- Repeat across scenarios and horizons to build the trajectory.
What you get back
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Integrated flood band
Single compound flood exposure per asset.
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Component breakdown
How much the river vs pluvial component contributes.
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Portfolio roll-up
Compound flood exposure across the asset base.
- Low
- Medium
- High
Portfolio flood-band migration
How the integrated flood mix shifts as the scenario hardens.
How to read the band
- Use the integrated band as your single flood-screening view; drop into the river or pluvial pages when you need to know which driver dominates.
- An asset can be Medium for both river and pluvial yet integrate to High — compound exposure is the point.
- As with the components, High means "investigate further", not "loss expected".
Disclosure relevance
- IFRS S2 Aggregate physical-risk exposure across related hazards.
- IFRS S2 Resilience assessment for compound flood risk.
- TCFD Portfolio-level physical risk metrics.
Limitations
- Inherits the limitations of both the river and pluvial models.
- Screening scope: a prioritisation view, not a combined hydraulic model.
- Does not model interaction effects beyond the shared band-aligned combination.
Screening-level analysis; not investment or engineering advice.
Bring integrated flooding screening to your portfolio
Screened, banded and framed for IFRS S2 and TCFD disclosure.