New and improved flood risk solutions for Australia

Extreme rainfall events in recent years have demonstrated the dangers posed by flooding in Australia and has highlighted the importance of using high-quality flood data to manage risk.

Flood modelling is a complex process and for large nations such as Australia this represents a significant challenge. Since its launch in 2014 Ambiental’s Australia FloodMap has become relied upon by insurance companies who want to assess flood risk at property level. By incorporating high precision LiDAR terrain data very high levels of accuracy are achievable. Ambiental’s Australia FloodMap urban model has more LiDAR than competing products and the coverage has expanded significantly through this latest release.

Australia FloodMap LiDAR model coverage at 5 meter grid resolution now provides high precision flood mapping for over 77% of the population. This recent expansion provides over 45,500km² additional LiDAR for Queensland and New South Wales, taking the total 5 meter LiDAR coverage to over 213,000km². In rural areas where LiDAR is not available Ambiental uses the best available alternative which is the hydrological enforced DEM-H topography data from GeoScience Australia. Additionally, the hydrological approach used in the rural model has been improved to better leverage the latest available science. All of this has resulted in major improvements to the Rural model hazard outcomes.

Rating risk with the FloodScore database

Following the success of Ambiental’s innovative FloodScore risk rating database for the United Kingdom this convenient way of view flood risk data for individual properties is now available for Australia. FloodScore has become a trusted solution for insurance customers and is particularly useful for clients who do not use Geographic Information Systems and may not have specialists for interpreting flood maps. With FloodScore this is not necessary because data is delivered already associated with property level exposure data. This database solution provides a property specific ‘FloodScore’ which rates flood risk using an algorithm which assigns a 0-100 score, with 100 represent extreme flood risk. This enables rapid screening and simplified setting of premiums across an insurance portfolio.

FloodScore is particularly attractive to smaller insurance brokers who only need to pay for the data they access. This is achieved via the FloodScore online service or through integration of the FloodScore API (Application Protocol Interface). Alongside the convenient risk scoring the FloodScore database also includes fields detailing flood depth at multiple return periods for fluvial, pluvial and tidal flood types, for defended and undefended scenarios. The product is also available as an entire national database which unlocks the capability to perform detailed flood risk analysis.

In Australia the FloodScore product provides point-based risk ratings and also building outline risk ratings. The G-NAF exposure database from PSMA includes the location and address of every property in Australia. Using a buffered approach flood data is extracted to the database for each property. The premium version of the product also incorporates flood depths extracted to building footprints which enables even greater accuracy.

Probabilistic modelling of catastrophic events

Catastrophe modelling is used by reinsurance companies and governments to understand the potential losses posed by future flood events. Reinsurers need to develop a good understanding of the uncertainty around predictions. This can be challenging because actual floods happen infrequently and there is typically limited previous historic events to reference. Probabilistic modelling overcomes this challenge through modelling tens of thousands of synthetic events driven by real world data and patterns of correlation. This effectively produces a huge catalogue of events to analyse the distribution of results to better understand uncertainty.

Ambiental Australia FloodCat was launched in 2015 and provided the most comprehensive and detailed view of catastrophic flood losses on the market. This relaunch incorporates new hazard data from Australia FloodMap to unlock the benefits of our latest refinements in modelling approach and enhanced topographic accuracy. It also includes a new catchment-based approach to event generation which makes individual events more realistic. The latest model also includes the incorporation of up to date PSMA G-NAF exposure data and flood intensities extracted using our FloodScore methodology. This improves risk detection and ensures consistency throughout the Ambiental product range. Furthermore, Australia FloodCat now can incorporate building outlines data to produce the most definitive national view of risk achievable.

Models validated against recent flood events in Australia

The need for better digital flood risk solutions for Australia has been growing in recent years following a series of major floods which have resulted in many fatalities, major damage to property and infrastructure and severe disruption to the economy and the Australian population. Models must be kept up to date to better understand the probability of extreme events and leverage the latest science and advancements in computing. In the last 10 years alone, there have been around a dozen major flood events across the country, affecting large areas of New South Wales, Western Australia, Victoria and Queensland. In March 2017 major flooding occurred as cyclone Debbie ravaged the Eastern side of Australia and parts of Southern Australia. In 2019 the city of Townsville was hit again by major floods as unprecedented monsoon rainfall lead to an emergency release of water from the Ross River Dam which flooded many properties and decimated agricultural lands.

Climate change threatens to increase flood risk in some parts of Australia and Ambiental is exploring the application of innovative approaches to quantify this risk. Ambiental FloodFutures is a tool for screening exposure portfolios against long-term flood risk which incorporates climate models to provide a range of future scenarios. With the capability to produce this data anywhere in the world Ambiental is looking to make this technology available for Australia. Ambiental is also at the forefront of developing a systems-based approach to managing flood risk through the development of flood risk management analysis and alerting dashboards. These cloud-based applications provide automated visualization and impact analysis to provide meaningful actionable intelligence.