Flood Vulnerability Factors

Water resource systems are vulnerable to floods due to three main factors; exposure, susceptibility and resilience.

Understanding each concept and considering certain indicators may help to characterize the vulnerability of different systems, by which certain actions can be identified to decrease it.

Exposure: Exposure can be understood as the values that are present at the location where floods can occur. These values can be goods, infrastructure, cultural heritage, agricultural fields or mostly people. The indicators for this component can be separated in two categories; the first one covers the exposure of different elements at risk and the second one give details on the general characteristics of the flood.

Exposure is defined as the predisposition of a system to be disrupted by a flooding event due to its location in the same area of influence.

Susceptibility: Susceptibility relates to system characteristics, including the social context of flood damage formation. Especially the awareness and preparedness of affected people regarding the risk they live with (before the flood), the institutions that are involved in mitigating and reducing the effects of the hazards and the existence of possible measures, like evacuation routes to be used during the floods.

Susceptibility is defined as the elements exposed within the system, which influence the probabilities of being harmed at times of hazardous floods.

Resilience: Resilience to flood damages can be considered only in places with past events, since the main focus is on the experiences encountered during and after the floods.

In this study resilience is defined as the capacity of a system to endure any perturbation, like floods, maintaining significant levels of efficiency in its social, economical, environmental and physical components.

The vulnerability of a system to flood events can be expressed with the following general equation:

Factors of Vulnerability