Fluvial flood risk management in a changing world

Abstract

Abstract. Flood risk emerges from the interaction of hazard and vulnerability. Over recent decades the notion of risk being the basis for flood management decisions has become widely accepted and operationalised through the use of models and quantified risk analysis providing the evidence for risk-informed decision making. However, it is now abundantly apparent that changes in time, at a range of scales, of pertinent variables that determine risk are not a second order consideration but, instead, fundamentally challenge the conventional approach to flood risk management. The nature of some of these changes, particularly those that operate on extended timescales, are highly uncertain, yet decisions that may have implications for several decades still have to be taken. In this paper we explore how flood risk management may be adapted to address processes of uncertain future change. We identify a range of levels at which change may be incorporated in decision making: in the representation of uncertain non-stationary quantities; in the rules that are used to identify preferred options; in the variety of options that may be contemplated for flood risk management; in the scope of problem definition, which increasingly extends to address multiple hazards and multiple functions of river basins; and in the social and organizational characteristics that promote adaptive capacity. Integrated responses to changing flood risk need to attend to each of these levels of decision making, from the technicalities of non-stationarity, to the promotion of resilient societies.

Flood risk, climate change and settlement development: a micro-scale assessment of Austrian municipalities

“…As both aspects of risk-hazard and vulnerability-are nonstationary, flood risk is a ''dynamic entity'' (Merz et al 2010). This changeable characteristic of flood risk is emphasized in the EU Floods Directive (2007/60/EC), which specifies that ''…human activities (such as increasing human settlements and economic assets in floodplains…) and climate change contribute to an increase in the likelihood and adverse impacts of flood events '' (EU 2007).…”

Holistic approach to flood risk assessment in areas with cultural heritage: a practical application in Ayutthaya, Thailand

“…An understanding of flood vulnerability typically requires knowledge of the possible impacts of flooding. There is an extensive literature on flood damage or impact assessment (Messner et al 2007;Merz et al 2010;Hammond et al 2015). Flooding has the potential to cause harm in many different ways, and these impacts can be considered as consisting of physical, social, institutional, economic, and environmental dimensions.…”

“…Flood risk assessed with this approach typically relies on the quantification of risk through computational flood modelling (see, for example, Vojinovic and Tutulic 2009), and the enumeration of assets at risk and their value. To obtain the most complete understanding of flood risk, all the dimensions of impacts or damage should be included (Merz et al 2010). However, FRAs commonly focus on those impacts that can be quantified in financial terms, such as the cost of damage to property and business disruption.…”

Uncertainty and sensitivity analysis of flood risk management decisions based on stationary and nonstationary model choices

“…There has been a call to identify nonstationary probabilistic models instead of relying upon the stationary assumption in practical flood risk management problems [6]. Yet abandoning stationary probabilistic model and identifying approaches of nonstationary for practical use in flood risk management raises challenges to flood risk analysts and the research community [7,8].…”