Adaptation to flood risk: Results of international paired flood event studies

Abstract

As flood impacts are increasing in large parts of the world, understanding the primary drivers of changes in risk is essential for effective adaptation. To gain more knowledge on the basis of empirical case studies, we analyze eight paired floods, that is, consecutive flood events that occurred in the same region, with the second flood causing significantly lower damage. These success stories of risk reduction were selected across different socioeconomic and hydro‐climatic contexts. The potential of societies to adapt is uncovered by describing triggered societal changes, as well as formal measures and spontaneous processes that reduced flood risk. This novel approach has the potential to build the basis for an international data collection and analysis effort to better understand and attribute changes in risk due to hydrological extremes in the framework of the IAHSs Panta Rhei initiative. Across all case studies, we find that lower damage caused by the second event was mainly due to significant reductions in vulnerability, for example, via raised risk awareness, preparedness, and improvements of organizational emergency management. Thus, vulnerability reduction plays an essential role for successful adaptation. Our work shows that there is a high potential to adapt, but there remains the challenge to stimulate measures that reduce vulnerability and risk in periods in which extreme events do not occur.

Drought Analysis in Europe and in the Mediterranean Basin Using the Standardized Precipitation Index

“…In this work, dry periods were evaluated using the SPI at different time scales (3,6,12, and 24 months). While the 3-and 6-month SPI describe droughts that affect plant life and farming, the 12-and 24-month SPI influence the way water supplies and reserves are managed [50,51].…”

“…Since the beginning of the 20th century, the highest concentration of anthropogenic greenhouse gases since the pre-industrial era and an increase in mean global temperatures of about 0.9 • C have been detected [1]. As a consequence, anthropic systems and terrestrial ecosystems are becoming more vulnerable to environmental phenomena and an increase in floods, heat waves, forest fires, and droughts can be expected [2,3]. In particular, the Intergovernmental Panel on Climate Change (IPCC) warned about the possible intensification of droughts in this century, especially in some areas such as the Mediterranean basin [1].…”

Integrating human behaviour dynamics into flood disaster risk assessment

“…More broadly, the results of recent ABM studies show that societal water-climate systems all have the characteristics of complex systems, marked by time periods of both stability and large dynamics; 81,82 historical data regarding investments in flood protection show little change in the behavior of governments and households after floods that had a small impact, and large investment dynamics in adaptation following large disasters. 83 For instance, recent research into flood-risk trends in the Netherlands shows that, without considering behavioral aspects, future risk is overestimated by a factor of 2. 77 This is confirmed by Wind et al, 84 who observed a 35% decrease in losses for a large flood on the River Meuse in 1995 compared to a similar flood in 1993, which was primarily caused by the adaptive behavior of households.…”

An Operational Method for Flood Directive Implementation in Ungauged Urban Areas

“…Floods are among the most destructive water-related hazards and are mainly responsible for the loss of human lives, infrastructure damages and economic losses [1]. Nowadays, there is a rising global awareness of flood damage mitigation due to the increase in frequency, magnitude, and intensity of flood events [2,3]. In the Mediterranean region, there are many small-medium sized watersheds, which have significant elevation changes (from mountainous areas to plains and even coastal areas).…”