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
River (fluvial) band
River flooding model
The fluvial component, already banded on the shared axis.
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
Integrated flood band
Single compound flood exposure per asset.
Component breakdown
How much the river vs pluvial component contributes.
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 S2Aggregate physical-risk exposure across related hazards.
- IFRS S2Resilience assessment for compound flood risk.
- TCFDPortfolio-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.