Effectiveness of emergency measures for flood prevention

• Published in: Journal of flood risk management Vol. 9; no. 4; pp. 320 - 334
• Main Authors: Lendering, K.T., Jonkman, S.N., Kok, M.
• Format: Journal Article
• Language: English
• Published: London Blackwell Publishing Ltd 01-12-2016; John Wiley & Sons, Inc
• Subjects: Emergency measures; Flood control; Flood insurance; flood prevention; flood risk; risk and reliability analysis; risk reduction; Netherlands
• ISSN: 1753-318X; 1753-318X
• DOI: 10.1111/jfr3.12185

Emergency measures, such as sandbags, are often used during flood events to prevent breaches in flood defences. However, there is limited insight into their contribution to flood prevention. This paper describes a method to determine the reliability of a system of flood defences including emergency measures. The reliability of the emergency measure depends on the completion of three events: ‘Detection’, ‘placement’ and ‘construction’. Both detection and placement can fail due to human error or insufficient time; construction can fail due to structural failure. The method was applied to a case study in the Netherlands, in which the reliability of a flood defence system including emergency measures was determined. We found that emergency measures can increase the reliability with a factor 1.5–4, depending on the considered failure mode of the dike. Failure of detection and placement, and the underlying human reliability, had the highest contribution to the failure probability. Emergency measures proved to be cost effective, but are still less cost effective as traditional reinforcements. They could play a role as an interim solution to reduce flood risk.