Global-scale river flood vulnerability in the last 50 years

Abstract

The impacts of flooding are expected to rise due to population increases, economic growth and climate change. Hence, understanding the physical and spatiotemporal characteristics of risk drivers (hazard, exposure and vulnerability) is required to develop effective flood mitigation measures. Here, the long-term trend in flood vulnerability was analysed globally, calculated from the ratio of the reported flood loss or damage to the modelled flood exposure using a global river and inundation model. A previous study showed decreasing global flood vulnerability over a shorter period using different disaster data. The long-term analysis demonstrated for the first time that flood vulnerability to economic losses in upper-middle, lower-middle and low-income countries shows an inverted U-shape, as a result of the balance between economic growth and various historical socioeconomic efforts to reduce damage, leading to non-significant upward or downward trends. We also show that the flood-exposed population is affected by historical changes in population distribution, with changes in flood vulnerability of up to 48.9%. Both increasing and decreasing trends in flood vulnerability were observed in different countries, implying that population growth scenarios considering spatial distribution changes could affect flood risk projections.

An operational procedure for rapid flood risk assessment in Europe

“…de Bruijn et al, 2014) and the use of mortality rates calculated from previous flood events (e.g. Jongman et al, 2015;Tanoue et al, 2016) are more feasible for integration, and these could be tested for the next releases of the risk forecasting procedure.…”

Human–water interface in hydrological modelling: current status and future directions

“…Among different land use changes, urbanization is of specific interest in recent impact studies, e.g. with the focus on flood risks, hazards, and vulnerability Muis et al, 2015;Sampson et al, 2015;Tanoue et al, 2016;Winsemius et al, 2013). At present, more than half of the world's population lives in urban areas and rapid urbanization is taking place in many developed and developing regions of the world (Klein Goldewijk et al, 2011).…”

Improving accuracy and quantifying uncertainty in flood loss estimations through the use of multi-model ensembles

“…However, data required to perform such assessments are usually not available, as scarcity of data is still a major problem in the field of flood risk (Merz et al, 2010). Moreover, exposure and vulnerability tend to change over time, which is likely to affect loss estimates (Tanoue et al, 2016). Another issue of a more practical nature is that collecting, implementing and comparing flood loss models is laborious and time consuming.…”

“…The lack of an established procedure to select suitable flood loss models from the many available in the literature means that model selection is often done rather arbitrarily (Scorzini and Frank, 2015), which can negatively impact the quality of flood loss estimations and lead to suboptimal investment decisions based on model outcomes (Wagenaar et al, 2016). 25 A critical issue in flood loss modelling is uncertainty (Merz et al, 2004), which is usually high and can significantly contribute to overall uncertainty in flood risk analyses (de Moel and Aerts, 2011). Model uncertainty is mainly related with parameter representation, whereby fewer parameter than those theoretically needed to describe physical damage processes are used, and with insufficient data and/or knowledge about damage processes (Wagenaar et al, 2016).…”