How to incorporate climate change projections in the probabilistic assessment of civil structures
I.E. Özer 1 a, N.E. Meinen 2 a, R.D.J.M. Steenbergen 1 3
1 TNO, Department of Structural Reliability, Delft, the Netherlands
2 Faculty of Engineering, University of Southern Denmark, Odense, Denmark
3 Ghent University, Faculty of Engineering and Architecture, Department of Structural Engineering, Ghent, Belgium
a These authors contributed equally.
Civil structures such as buildings, bridges, and flood defences, need to be designed to withstand extreme climatic actions during their entire design lifetime. Due to climate change, more extreme conditions are expected for those events that are relevant to civil structures (e.g. an increase in sea level or precipitation). Projecting the future climate is however an extremely challenging task which is highly subjected to uncertainties. This study investigates how these uncertainties can be included in the probabilistic design and assessment of civil structures. This is done by evaluating the uncertainties in global (IPCC, AR5) and regional (KNMI'14, the Netherlands) climate change projections. We identified that there is currently a discrepancy between the expectations of structural engineers with respect to uncertainty quantification on the one hand, and the limitations of climate science on the other hand. This leads to the following engineering challenges on (1) how to include or quantify uncertainties related to the climate change scenarios; (2) how to translate the available information about modelling uncertainties in climate models into the required quantitative information for traditional risk and reliability assessments; and (3) how to employ the provided climate change projections for the 30-year mean-values for the estimation of the required 50, 1000, or even 10.000 year extreme values. We discussed how these challenges lead to pragmatic modelling choices of engineers, and how this potentially leads to reduced structural safety. However, we believe that with a close collaboration between climate experts and engineers, many of these challenges can be addressed within the current limitations of science.
Key words: Climate change, structural reliability, modelling uncertainties, AR5, KNMI'14