Private Flood Mitigation Measures in a Changing Risk Environment
Despite the considerable efforts to reduce the risk of natural disasters, floods remain the most frequent and devastating natural hazard worldwide. In the future, flood risk is projected to further increase in many regions as a result of an increased concentration of people and economic assets in flood-prone areas and the effects of global warming.
Just as flood risk is continuously changing, flood risk management is also constantly in a state of flux and needs to be adapted to a changing environment. Flood management in Europe and on a global level has increasingly shifted to integrated risk management approaches, including measures that reduce damage and exposure. Nowadays, the contribution of private households to damage reduction by means of flood mitigation measures, such as mobile flood barriers or flood-adapted building use has become an important component of integrated flood-risk management strategies in many countries.
However, despite the growing importance of private flood mitigation measures in contemporary integrated flood risk management, knowledge on them remains scarce. Amongst other things, information on the long-term development and current level of the implementation of private flood mitigation measures among flood-prone households is hardly available. And, only a few studies have examined the damage-reducing effect of flood mitigation measures on the basis of empirical damage data collected at the household level. Moreover, better knowledge of the factors that influence individual’s decisions to protect themselves against flood impacts is essential, in order to successfully manage the current transition from traditional flood control approaches to integrated flood-risk management.
Data from flood-prone households along the Rhine show that households’ direct disaster experience is an important trigger for the implementation of flood mitigation measures (Figure 1). Moreover, the household data also demonstrate the damage-reducing effect of flood mitigation measures implemented by private households. A comparison of the precautionary behaviour of households and the damage suffered during two severe flood events in 1993 and 1995 demonstrated that the damage reduction of more than 50 per cent in 1995 compared with 1993 can indeed be attributed to an improved preparedness of the flood-prone population.
As far as the factors that influence individual’s decisions to protect themselves against flood impacts are concerned, a review of 16 peer-reviewed studies indicates that high risk perceptions do not necessarily result in improved mitigation behaviour, as is often suggested. This is confirmed by own analyses of survey data along the Rhine and from central Vietnam. Instead, it is found that flood-coping appraisals and the social environment are important variables of influence on different types of flood mitigation behaviour.
Overall, it can be concluded that increasing the level of flood mitigation measures at the household level can be viable strategy in a changing risk and risk management environment. This is especially the case for areas that are prone to frequent floods.
Philip Bubeck has performed research on this subject for his PhD thesis. His public defence is scheduled for April 8th at 11:45.
Publications on which thesis is based:
Bubeck, P., Botzen, W.J.W., Kreibich, H. & Aerts, J.C.J.H. 2013. Detailed insights into the influence of flood-coping appraisals on mitigation behaviour. Global Environmental Change – Human and Policy Dimensions, in review.
Bubeck, P., Botzen, W.J.W., Kreibich, H. & Aerts, J.C.J.H. 2012. Long-term development and effectiveness of private flood mitigation measures: An analysis for the German part of the Rhine. Natural Hazards and Earth System Sciences, 12, 3507-3518.
Bubeck, P., Botzen, W.J.W. & Aerts, J.C.J.H. 2012. A review of risk perceptions and other factors that influence flood mitigation behavior. Risk Analysis, 32(9), 1481–1495.
Bubeck, P., Botzen, W.J.W., SUU, L.T.T. & Aerts, J.C.J.H. 2012. Do flood risk perceptions provide useful insights for flood risk management? Findings from central Vietnam. Journal of Flood Risk Management, 5(4), 295-302.
Bubeck, P., De Moel, H., Bouwer, L. M. & Aerts, J.C.J.H. 2011. How reliable are projections of future flood damage? Natural Hazards and Earth System Sciences, 11(12), 3293-3306.
Te Linde, A. H., Bubeck, P., Dekkers, J. E. C., De Moel, H. & Aerts, J. C. J. H. 2011. Future flood risk estimates along the river Rhine. Natural Hazards and Earth System Sciences, 11(2), 459-473.
Bubeck, P., Kreibich, H., Penning-Rowsell, E., Klijn, F. & De Moel, H. 2012. Explaining differences in flood management approaches in Europe and the USA – A comparative analysis. In: Klijn, F & T. Schweckendiek (eds.). Comprehensive flood risk management. Research for policy and practice. Proceedings of the FLOODrisk2012 conference, November 2012, Rotterdam. CRC press, Balkema.