The 2023 Plinius Medal is awarded to Alberto Viglione for seminal contributions to understanding and assessing hydrological extremes.
Alberto Viglione is associate professor at the Politecnico di Torino, Italy. Before his current position, he worked at the Vienna University of Technology, Austria, and at the University of Illinois, USA. He presently serves as a Vice-President of the EGU Division on Hydrological Sciences, as a secretary of International Association of Hydrological Sciences International Commission on Water Resources System, and as a leader of the Panta Rhei International Association of Hydrological Sciences working group “Understanding flood changes”.
Viglione has dedicated most of his research to understanding and assessing the probabilities of hydrological extremes, advancing substantially the methods to quantify the interplay of climatic, hydrologic, and human processes in river basins. These advancements allowed him to assess the probabilities of hydrological extremes, to anticipate extreme, unexpected events, and to explain the space-time dynamics of extremes.
Viglione has achieved major breakthroughs when addressing two challenges of natural hazards research, namely, extrapolating from observed events to the more relevant extreme events, and deciphering the space-time dynamics of risk. He developed a framework for combining the various pieces of information that could assist in understanding and predicting rare floods, termed “Flood Frequency Hydrology”, which differs from previous approaches in its ability to combine local flood data with historic floods, floods in neighbouring catchments and with flood processes. He framed the idea in Bayesian terms and demonstrated that the additional information can significantly reduce the estimation uncertainty.
Viglione developed models that explicitly represent the human impact on the occurrence of unexpected floods, showing that the effect of feedback mechanisms between humans and flood occurrence heavily determines their co-evolution. He explored the role of community risk-coping culture (such as collective memory, risk-taking attitude and trust of the community in risk reduction measures) on future flood damage and economic growth. To understand how flood risk dynamics changes over time, Viglione developed a new method for identifying flood-rich periods. Applying this method to more than 100 historical flood series’ based on documentary evidence, he showed, for the first time, that the past three decades were among the most flood-rich periods in Europe over the past 500 years. Viglione pioneered the research on the question of whether changes equally apply to small and large floods, and succeeded in developing completely new approaches for attributing observed changes to their potential causes.
Viglione’s work has important implications for risk mitigation. His approaches have been included into the national flood risk assessments in Austria, Germany and the USA.
In closing, Viglone’s interdisciplinary approach, integrating hydrology, climatology, history and socio-hydrology, has significantly deepened our understanding of hydrological extremes with implications for the flood risk assessment and disaster risk reduction.