Determination of optimal safety standard for flood defence system of coastal region in Giao Thuy - Nam Dinh

Abstract

     In implementation of new flood defences and upgrading of exisiting dike system, decision on how safe is safe enough is crucial. This can be done by determination of so-called optimal safety standard which not only depends on technical aspects but also on value to be protected of the protected area and pontential risks due to flood of the considered area. This paper present risk based approach in determination of optimal safety standard for a flood prone area which is protected by a single "dike ring". Application is made for a case of dike ring protecting a coastal region belongs to Giao thuyr district, Nam Dinh province. Risk based framework in this paper takes into account economic and individual risks. Findings show that the present socio-economic development of the research area required a higher safety standard, by factor of 2 to 5 compared to exisiting one.