Flooding is complex and highly localised in nature, meaning risk can vary significantly over short distances. Details like terrain, land use, property resilience and defences all play a significant role. And the risks arise from multiple sources – surface water (pluvial), river (fluvial) and coastal flooding, each behaving differently and presenting distinct challenges in terms of impact and potential mitigation.
- Surface water flooding is typically driven by intense rainfall overwhelming drainage systems, often affecting areas in a very short space of time
- River flooding results from sustained rainfall across catchments, causing rivers to overflow and potentially affecting large areas
- Coastal flooding is driven by high-tides and storm surge impacting lower-lying coastal areas
Mapping surface water, river and coastal flooding worldwide
JBA’s global flood maps provide high-resolution coverage for all three flood hazards, at 30 m resolution anywhere in the world, with 5m resolution for UK, Ireland, continental Europe, USA and key populated regions of Australia.
Understanding each flood type separately is vital – but looking at them together provides a more complete picture. Multiple hazards may impact the same location under varying conditions or even concurrently, posing a significant challenge. Our maps have always supported comprehensive analysis and include optional flood defences layers, helping risk managers in insurance and businesses to test exposure with and without current protection.
Each flood type provides valuable insight that can be used by insurance and financial sectors, global businesses and international organisations:
- Surface water flood insight highlights localised, often more unexpected risks – especially important in urban areas and for assessing flash flood potential at individual property level
- River flood insight identifies widespread regional exposure – useful for setting risk thresholds, portfolio accumulation, portfolio structuring, infrastructure planning and regulatory requirements
- Coastal flood is important for coastal asset portfolios, pricing decisions, resilience planning and property protection plans
Reflecting our commitment to continuously enhance and develop our maps, we offer consistent coastal flood coverage across all regions.
Our latest flood map updates have expanded our coastal coverage to provide coastal flood maps around all coastlines worldwide. Covering return periods from 20 to 1,500 years, the coastal flood maps are delivered at 30m resolution globally. (We also provide 5m in the UK, Ireland and parts of USA). The maps were developed using reputable, peer-reviewed estimates of extreme sea level from the Global Tide and Surge Model (GTSM), with the flooding mapped onto high-quality coastal terrain data.
Together this comprehensive flood map package is suitable for a broad range of applications including underwriting, pricing, portfolio analysis, climate resilience assessment and regulatory requirements.