|Uncertainty on coastal flood risk calculations, and how to deal with it in coastal management: case of the Belgian coastal zone|
Verwaest, T.; Vanneuville, W.; Peeters, P.; Mertens, T.; De Wolf, P. (2007). Uncertainty on coastal flood risk calculations, and how to deal with it in coastal management: case of the Belgian coastal zone, in: Flood Risk Assessment II: proceedings of a conference held by the Institute of Mathematics and its Applications, September 2007. pp. 151-157
In: (2007). Flood Risk Assessment II: proceedings of a conference held by the Institute of Mathematics and its Applications, September 2007. Institute of Mathematics and its Applications: Essex. ISBN 978-0-905091-20-4. 220 pp., more
Coastal zone management; Flooding; Risks; ANE, Belgium, Belgian Coast [Marine Regions]; Marine
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A coastal flood risk calculation estimates the damage by coastal flooding for a certain time horizon. Fivedifferent sources of uncertainty can be distinguished: unpredictability of the weather; uncertainty on theextreme value probability distribution of storm surges; unknown future values of economic growth rate,population growth rate, sea level rise rate and discount rate; limited knowledge of the behaviour of thecoastal system; limited amount of measurements about the state of the coastal system. From a preliminaryanalysis for the Belgian coastal zone it is clear that the combined effect of these different sources ofuncertainty results in a very large uncertainty on the calculated risk, namely a sigma of a factor more than10. Some important sources of uncertainty are impossible to decrease substantially by doing research ormeasurements. Therefore the only option for coastal management is to deal with these large uncertainties.It is suggested to use calculation results relatively, namely to compare scenarios of coastal management inorder to determine which scenario can best use an available budget for investment. Also it is concludedthat risk calculation results would best be compared as ratios between scenarios (in %), not as differences(in euro/year).