Risk based approach for safety standard of coastal flood defences in Vietnam.

Abstract

This paper focuses on risk analysis and safety aspects of coastal flood defences in Vietnam. The sea dike system has been actually designed by a 20 to 25 years return period. From the current situation it seems that the dike system is not sufficient to withstand the actual sea boundary condition. As present situation the total annually economic damages of Vietnam due to floods and typhoons is about 1.0 to 1.2 % of its GDP. Accurate safety assessment of the existing coastal defence system is, therefore, of large importance. It can quantify the possible consequences after failure of the defensive system, the loss of life, economic, environmental, cultural losses and further intangibles. To determine if safe is safe enough, an investigation is carried out in this paper to determine other types of risks to which the local population is exposed, apart from the flood risk. The issues addressed in this paper may support decision-maker to find the optimal protection levels of the coastal regions and for a long term planning of rehabilitation of the coastal flood defences in Vietnam.