Epistemic uncertainties and natural hazard risk assessment – Part 1: A review of the issues
K. J. Beven1,2, W. P. Aspinall4, P. D. Bates5, E. Borgomeo7, K. Goda3, J. W. Hall7, T. Page1, J. C. Phillips4, J. T. Rougier6, M. Simpson7, D. B. Stephenson8, P. J. Smith1, T. Wagener3,9, and M. Watson41Lancaster Environment Centre, Lancaster University, Lancaster, UK 2Department of Earth Sciences, Uppsala University, Uppsala, Sweden 3Department of Civil Engineering, Bristol University, Bristol, UK 4School of Earth Sciences, Bristol University, Bristol, UK 5School of Geographical Sciences, Bristol University, Bristol, UK 6School of Mathematics, Bristol University, Bristol, UK 7Environmental Change Institute, Oxford University, Oxford , UK 8Department of Mathematics and Computer Science, Exeter University, Exeter, UK 9Cabot Institute, University of Bristol, Bristol, UK
Received: 21 Oct 2015 – Accepted for review: 26 Nov 2015 – Discussion started: 07 Dec 2015
Abstract. Uncertainties in natural hazard risk assessment are generally dominated by the sources arising from lack of knowledge or understanding of the processes involved. There is a lack of knowledge about frequencies, process representations, parameters, present and future boundary conditions, consequences and impacts, and the meaning of observations in evaluating simulation models. These are the epistemic uncertainties that can be difficult to constrain, especially in terms of event or scenario probabilities, even as elicited probabilities rationalized on the basis of expert judgements. This paper reviews the issues raised by trying to quantify the effects of epistemic uncertainties. Such scientific uncertainties might have significant influence on decisions that are made for risk management, so it is important to communicate the meaning of an uncertainty estimate and to provide an audit trail of the assumptions on which it is based. Some suggestions for good practice in doing so are made.
Beven, K. J., Aspinall, W. P., Bates, P. D., Borgomeo, E., Goda, K., Hall, J. W., Page, T., Phillips, J. C., Rougier, J. T., Simpson, M., Stephenson, D. B., Smith, P. J., Wagener, T., and Watson, M.: Epistemic uncertainties and natural hazard risk assessment – Part 1: A review of the issues, Nat. Hazards Earth Syst. Sci. Discuss., 3, 7333-7377, doi:10.5194/nhessd-3-7333-2015, 2015.