Author(s)

T. Viseu & A. B. de Almeida

Abstract

Part of the losses that occur in a flood prone area depend on the flood characteristics, especially on the flood level of danger which is directly linked to the values of water depth and flow velocity, as well as the time of the flood arrival. The other losses depend on the vulnerability of the flood prone area. However, in real situations the conditional objective probabilities related to losses and hydrodynamic characteristics are very difficult obtain. A nonprobabilistic methodology to estimate this operator, which affects human lives as well as economical and environmental losses in the downstream valley, is presented, through the development of a downstream valley vulnerability index. The calculation of the vulnerability index is performed by a simple computer application using MS Excel software from Microsoft. The determination of the index vulnerability of a Portuguese dam valley is also performed. Keywords: vulnerability, loss of life, damages, index, flood, flood prone area. 1 Introduction The ageing of dams, changes in hydrologic conditions and the increasing population in valleys justify there being greater attention paid to dam safety and valley management. Potential dam failures, as well as the public pressure for a safer environment in contemporary society, make the risk evaluation of downstream valleys mandatory. In the case of a dam failure, the downstream valley risk evaluation depends on the event probability of occurrence (P(Ei)) and on the conditioned probability

Keywords

vulnerability, loss of life, damages, index, flood, flood prone area.