Natural Hazards and Risks in a Changing World (NatRiskChange)

NatRiskChange improved methods for analysing and predicting natural hazards - such as floods, earthquakes and landslides - especially in the context of changing environmental condi-tions. Scientists from Potsdam and Berlin with expertise from environmental and geosciences, meteorology, hydrology, risk research and mathematics teamed up to better understand natu-ral hazards and their societal impacts. Firstly, it was investigated how changes in natural sys-tems such as river catchments can be identified and what data is required for this. Secondly, it analysed how natural fluctuations can be distinguished from long-term changes in order to de-termine whether increasing risks (e.g., financial losses) are due to natural hazard processes themselves or to increased exposure or vulnerability. Thirdly, it was explored how this knowledge can be used to improve predictions. To answer these questions, the team adapted existing mathematical methods and developed new approaches for analysing large data sets. In particular, methods for describing and predicting earthquakes, including aftershocks, were improved: AI models and fibre optic sensors optimised early warning systems. Research on geomorphological hazards expanded the understanding of subglacial floods, sediment transport, glacial lake outburst floods (GLOFs) and landslides, leading to new insights into hazards and improved forecasting methods. Non-stationary methods for estimating extreme precipitation and flash floods were developed for heavy rainfall and flooding. Innovative models for estimating economic and infrastructural damage were created for flood vulnerability. Re-search on winter storms identified anomalies in the jet stream and cyclonic growth factors as key indicators of severe European winter storms. Dynamic vulnerability models now take into account previous storm damage, which improves damage estimates. With regard to droughts, forest fires and land degradation, an increase in hot and dry extreme events leading to crop failure and ecological vulnerability was identified. Improved fire models also offer new ap-proaches to managing land degradation and wildfires. The results of Nat-RiskChange have been published in numerous scientific publications. In addition, many findings provide valuable insights for policy makers, civil protection or the public to better prepare for disasters and build a more resilient future in the face of changing environmental conditions.