Probabilistic design of water defense systems in The Netherlands

After the disaster in 1953, a statistical approach to the storm surge level s was chosen and an extrapolated storm surge level would be the basis for d ike design. In recent decades, the development of reliability theory made i t possible to assess the flooding risks taking into account the multiple fa ilure mechanisms of a dike section and the length effect. It is pointed out that economic activity in the protected areas has grown considerably since the 1950s and that even more ambitious private and public investments, par ticularly in infrastructure, are planned. Moreover, the safety of a growing population is at stake. These considerations justify a fundamental reasses sment of the acceptability of the flood risks. (C) 2001 Elsevier Science Lt d. All rights reserved.