The vulnerability of establishment receiving the public and the companies in flood-prone zone: an assessment method in the watershed of Orb (Hérault, France)

Abstract

As part of the implementation of the flood mitigation plan supported by French government, we have realized a study of the vulnerability of establishments receiving the public and the companies faced with the flooding risks of the Orb and its tributaries. Our study deals with the Orb High Valley area that is affected by damageable Mediterranean flash floods. The assessment of vulnerability is led in five communes for which the Prevention of Predictable Natural Hazards Plan (PPR), has been approved. The first aim was to set up a diagnosis method of the vulnerability of all establishments admitting public (school, shops...) as well as companies located in flood prone zone. This method, based on a semi quantitative analysis assesses for each establishment, the human and economic vulnerability as well as the existence of protection and mitigation measures. This can be seen as personalized shits included in a Geographic Information System which use is very easy and fast. The study has brought out many problems common to the five communes: an important deficiency of protection and prevention measures at most of those establishments and a global lack of awareness on the flooding risk and the ability of dealing with it. Various solutions are proposed to reduce vulnerability (cofferdam, information campaign).