CROSSEU Brings Alpine Flood Risks into Focus: A Case from Trentino

The CROSSEU project’s findings from Case Study Area 4 (CSA#4), led by the University of Padova, highlight the socio-economic value of flood protection by combining physical and social sciences in a novel way. These results have been shared with researchers and policymakers to encourage evidence-based climate adaptation strategies. Notably, the study was presented through a poster at the 8th International Conference on Energy and Meteorology (ICEM 2025) with the title "Valuation of Social Benefits of Floods and Flash Floods Adaptation in Northeast Italy", a key forum where experts in climate services, risk governance, and resilience gathered to discuss the potential of such integrated approaches in shaping future policies across Europe.

It showcased how integrating advanced climate and hydrological modelling with stated preference methods—a form of economic valuation that captures public preferences—can help quantify the social value of flood mitigation and adaptation strategies.

By quantifying the social benefits of reducing flood impacts across residential, productive, agricultural, and touristic sectors, the study provides actionable insights that can help guide effective flood risk management and policy decisions in Northeast Italy and beyond.

Photo 1. Trentino Alto Adige map and examples of flood impacts in the region

Why This Case Study Matters: Focus on a Climate Change Hotspot

The study focuses on a Climate Change Hotspot (CCH) in Trentino-Alto Adige, an Alpine region increasingly affected by intense short-duration rainfall and flash floods. Its complex terrain and fragile geology, including numerous alluvial fans (landforms prone to debris flows and flooding), make it especially vulnerable.

Figure 1: Map showing spatial distribution of alluvial fans in Trentino

Similar flood risks are emerging in other Alpine and pre-Alpine regions—such as southern Germany, western Austria, and eastern France—where dense populations and critical infrastructure meet a changing climate.

Real-World Relevance: Learning from Storm Vaia

The study builds on the extreme weather event Storm Vaia (October 2018), which brought 200–500 mm of rain in 72 hours, causing flooding, landslides, and 11 fatalities in Northeast Italy.

[Insert photo from Storm Vaia or comparable flood event]

This storyline grounds the research in a real-world disaster and helps assess what mitigation and adaptation (M&A) strategies could have reduced the impact.

Methodology in a Nutshell: Science Meets Society

To evaluate the socio-economic risks and impacts of extreme precipitation events in the CCH, a six-step methodological framework was applied as follows:

Step 1: Climate Scenarios

Future flood scenarios were created using climate projections from advanced regional models, focusing on three 10-year periods (1996–2005, 2041–2050, 2090–2099) under the RCP 8.5 scenario.

Step 2: Data Integration

Climate data were combined with socio-economic information at the regional level. Population and economic factors were assumed constant due to lack of future data.

Step 3: Impact Assessment

Hydrological models transformed precipitation into flood impacts across five domains: residential, productive, roads, agriculture, and tourism. Economic damage for each was estimated via a Choice Experiment survey.

Step 4: Flood Risk Estimation

Hazard and exposure data were merged to create flood risk indicators, linked to economic valuations of impact reduction by land use type.

Step 5: Social Cost Estimation

Average social costs of flood impacts were calculated for future scenarios by aggregating estimates for the regional population.

**Step 6: **[Not described in the provided information]

Key Findings: What the Public Values Most

The research showed a clear public preference for investing in flood adaptation—especially when it protects homes.

Estimated Flood Exposure by 2090–2099

Under the worst-case climate scenario, flooded areas could reach:

• Residential areas: up to 16% in mountains
• Agricultural land: up to 25% in mountains
• Roads: up to 21%

Figure 3. Average individual economic valuation for total flood impact by land use category.

What People Are Willing to Pay

The Choice Experiment revealed that people are willing to pay annually to avoid a 1% increase in flooded land:

The highest concern is for residential areas, highlighting the importance of personal safety and home protection in public preferences. Productive areas and roads follow closely, underlining the economic and mobility risks tied to floods.

What’s Next?

Building on these findings, ongoing collaboration with the climate services community— including presentations at events like ICEM 2025—aims to strengthen ties between researchers and decision-makers. This engagement will help translate integrated flood risk valuations into effective climate adaptation policies that promote resilience and sustainability across Europe.

CSA#4 on Floods is part of the broader CROSSEU project, which delivers cross-sectoral climate risk assessments across European regions and hazards. The project supports policymakers in prioritizing adaptation investments by combining scientific evidence with public values.

To learn more about CROSSEU’s work on climate risk, energy, and social resilience, visit

the CROSSEU project website.