Verisk Inland Flood Model for the UK and the Republic of Ireland

Enhancements to the Verisk Inland Flood Model for the UK and the Republic of Ireland, formerly known as the Verisk Inland Flood Model for Great Britain.

Scope

The existing Great Britain domain is extended to the domains of Northern Ireland and the Republic of Ireland. We also updated vintage of data to create a state-of-the-art flood model to include precipitation and river streamflow data sets, digital terrain model (DTM) and precipitation modeling.

General model updates

Model domain

Expanded to include the following:
  • Northern Ireland
  • Republic of Ireland

Model resolution

  • Increased to 5 m resolution for inundation depth in floodplain
Hazard
  • Updated precipitation and river streamflow data sets
  • Updated/new digital terrain model (DTM)
  • Updated precipitation modeling approach using a coupled GCM and NWP model that is temporally and spatially downscaled
  • Flood velocity, debris flow, and event duration are explicitly modeled by event and location
  • Off-floodplain inundation depth calculated using two physically-based approaches, based on location and catchment size (previous version used a statistical approach/regression analysis techniques)
  • Intensity parameter of inundation depth is used for both on- and off-floodplain flooding
  • Off-floodplain urban drainage capacity accounted for using drainage facility design guideline data
Vulnerability
  • All flood damage functions (buildings and contents) use a component-based approach that assesses damage at a granular level, rather than for a building as a whole.
  • Demand surge
    • New demand surge framework for European models
    • Updated demand surge factors for the United Kingdom to reflect the updated modeled industry losses.
    • Added demand surge factors for the Republic of Ireland.
Catalogs and event sets
  • Stochastic catalog(s)
    • Updated 10,000-year catalog that represents the near-present climate
    • All event IDs are new.
  • New European AP Historical (2025) to replace older historical event sets and for the Verisk Inland Flood Model for the UK and the Republic of Ireland model will include:
    • 2000 UK Autumn Flood
    • 2008 Ireland Summer Flood
    • 2009 Ireland November Flood
    • 2011 Ireland October Flood
    • 2012 UK Summer Flood
    • 2014 UK Winter Flood
    • 2015 UK Winter Flood – Storm Desmond
    • 2015 UK Winter Flood - Storms Eva-Frank
    • 2020 UK Winter Flood
    • 2021 UK Summer Flood

Notes

The Verisk Inland Flood Model for Great Britain is now the Verisk Inland Flood Model for the UK and the Republic of Ireland.

Touchstone-specific updates

  • New support for specialized risk types
    • Builder's risk
    • Infrastructure
    • Large industrial facilities
    • Marine
  • Support for additional construction and occupancy codes
    • Construction: Updated to 137 classes total (including 20 marine asset classes)
    • Occupancy: Updated to 130 classes total (including 64 large industrial facility and 12 marine storage classes)
  • Support for 12 new secondary risk characteristics
    • Backwater valve protection
    • Base flood elevation
    • Basement finish type
    • Basement level count
    • Content vulnerability
    • Custom elevation
    • Custom flood standard of protection
    • First floor height
    • Floor of interest
    • Foundation type
    • Service equipment protection
    • Wet flood-proofing
  • Supported geographic resolutions expanded to include user-specified latitude/longitude.
  • Hazard impacts from velocity, debris flow, and duration will be explicitly modeled (by event by location) and will be added to Location-Level Event Intensities (LLEI) support.
  • Geographic variability of exposure distribution for buildings with unknown characteristics and combinations is captured by accounting for local building attributes.
  • Support for flood hazard maps/geospatial layers (20-, 50-, 100-, 200-, 250-, and 500-year return periods).

Touchstone Re-specific updates

  • Lines of business expanded to include
    • Automobile
    • Agriculture
  • Supported geographic resolutions updated to include
    • United Kingdom - postal area (2-digit)
      • Note: At the request of multiple clients the geographic resolution of United Kingdom industry and company loss files (ILFs/CLFs/CLAs) for the flood model has been updated to support postal area only. Legacy ILF and CLF files that contained postal sector level records will be aggregated to the postal area resolution during upgrade or import. This results in significant reduction in the size of these files as well as the size of the ResultsRe loss tables involving this model.
    • Republic of Ireland - CRESTA