Innovative approaches for flood risk assessment

Water is a vital natural resource and, as such, an integral part of our environment and climate system. Excessive water exposure during flood conditions and water scarcity during droughts pose fundamental risks to life and weaken socio-economic resilience. Present-day water management in many sectors has to be able to cope with extreme hydrological conditions.

The European research project IMPREX (IMproving PRedictions and management of hydrological EXtremes) was funded under the EU Framework Programme Horizon 2020. The project consortium, consisting of 23 renowned partners from nine countries, took up the challenge of developing methods and tools to improve predictions of hydro-meteorological extremes. The research focused on adapting climate information to the needs of six core sectors: flood risk assessments, hydropower, water transport, urban water management, agriculture and droughts. 

adelphi has developed a fact sheet for each sector. These describe and explain the most important products, provide practical examples, analyse implementation challenges for practitioners and show how IMPREX products can facilitate processes. The fact sheets are based on the work carried out within the context of the IMPREX research project and interviews with involved stakeholders.

This fact sheet presents two innovative approaches to meet existing challenges and improve flood risk assessment.

Floods are one of the most frequent natural hazards. IMPREX has developed a probabilistic, multivariable flood loss estimation model in close collaboration with relevant stakeholders, including insurance companies. The aim is to provide an improved short- to medium-term, seasonal and long-term flood risk assessment. The probabilistic approach is especially suitable for planning purposes and real-time assessments, where flood loss uncertainties play an important role. The model has been applied and validated successfully in three European river basins with varying spatial scales in Germany, Italy and Austria. 

The second IMPREX approach presented is an analytical framework for river basin authorities to assess risks and impacts of interrelated climatic processes. In order to efficiently design flood hazard and risk assessments, IMPREX analysed and assessed so-called “compound events”: a combination of processes contributing jointly to major impacts, such as heavy precipitation and storm surges. A better understanding of compound events enhances the reliability of flood statistics and flood hazard maps.

The project team conducted a case study that depicts the application of the flood loss estimation model in the insurance industry. This practical example shows that the model offers a comprehensive response to (re)insurance needs by delivering reliable information to evaluate flood risks.

Further fact sheets from this project:

• Hydrometeorological predictions for the hydropower sector – potential economic benefits
• Improved forecasting and risk management for the water transport sector
• Urban water supply systems
• Drought preparedness, mitigation and management – innovative approaches for the agricultural sector
• Europe's global water risk

Policy recommendations:

• Policy Brief: The importance of including compound events in the implementation of the Floods Directive
• Policy Brief: Probabilistic Approaches for Improved Flood Risk Assessment and Management under consideration of uncertainties
• Policy Brief: Towards successful implementation of preventive drought risk management in Europe
• Position Paper: Towards more action-oriented research and climate services – Lessons learned from IMPREX

Comprehensive brochure:

• Improving Predictions and Management of Hydrological Extremes – Synthesized results for policy and decision makers