Articles | Volume 10, issue 3
Nat. Hazards Earth Syst. Sci., 10, 509–527, 2010

Special issue: Risk management of extreme flood events

Nat. Hazards Earth Syst. Sci., 10, 509–527, 2010

  16 Mar 2010

16 Mar 2010

Fluvial flood risk management in a changing world

B. Merz1, J. Hall2, M. Disse3, and A. Schumann4 B. Merz et al.
  • 1Helmholtz Centre Potsdam, German Research Centre for Geosciences (GFZ), Section Hydrology, Telegrafenberg, 14473 Potsdam, Germany
  • 2Tyndall Centre for Climate Change Research, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK
  • 3Universität der Bundeswehr, Institute for Hydro Sciences (IfW), Water Management and Resources Engineering, Werner-Heisenberg-Weg 39, 85579 Neubiberg, Germany
  • 4Ruhr-University Bochum, Institute of Hydrology, Water Resources Management and Environmental Engineering, Universitätsstraße 150, 44801 Bochum, Germany

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.