The concept of vulnerability implies a measure of risk associated with the physical,
social and economic aspects and implications resulting from the system’s ability to
cope with the resulting event. Resilience implies the ability of an infrastructure
system to perform properly even when placed under pressure or the ability of the
infrastructure systems to absorb and recover from the impact of disruptive events
without fundamental changes in function or structure. Based on what is required to
face disasters, features should be inbuilt in the infrastructure (design, normal operation, etc) so as to offer better, if not complete, resilience to the system. As resilience
increases, the degree of damage for a given intensity hazard decreases. Measuring
resilience is not easy as this depends on the infrastructure system under study. It is
important to look at the ways resilience is being considered and use these as a
method to measure resilience, either qualitatively and quantitatively. Several
approaches have been proposed in this chapter to measure or compare resilience of
two infrastructure systems.
11.1 Vulnerability and Resilience
11.1.1 Vulnerability
A water supply network must ensure that the consumer obtains water when she
needs it. By extension, Fig. 11.1 shows what a customer expects from an infrastructure system or service.
The concept of vulnerability implies some risk combined with the level of social
and economic liability, and the ability to cope with the resulting event. Vulnerability
has been defined as the degree to which a system, or part of a system, may react
adversely during the occurrence of a hazardous event.
Thus people become “vulnerable” if access to resources either at a household, or
at an individual level is the most critical factor in achieving a secure livelihood or
recovering effectively from a disaster. The households with direct access to capital,
tools and equipment, and able-bodied members are the ones which can recover most
quickly when a disaster strikes. As such, the most vulnerable people are the poorest,
who have little choice but to locate themselves in unsafe settings.
11.1.2 Resilience of Systems
When a car is moving on an uneven road surface, the car will transmit, to the
passengers, the respective shocks sustained whenever the car goes over a hump or
into a pothole. But, if the shock absorber (car damping system) is excellent
(or should we say efficient), the shocks might only be slightly noticeable. Sometimes, these passages over humps or potholes are even enjoyed by children as they
slowly return to a more stable position. This is possible because the car springs are
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11 Infrastructure Resilience
social and economic aspects and implications resulting from the system’s ability to
cope with the resulting event. Resilience implies the ability of an infrastructure
system to perform properly even when placed under pressure or the ability of the
infrastructure systems to absorb and recover from the impact of disruptive events
without fundamental changes in function or structure. Based on what is required to
face disasters, features should be inbuilt in the infrastructure (design, normal operation, etc) so as to offer better, if not complete, resilience to the system. As resilience
increases, the degree of damage for a given intensity hazard decreases. Measuring
resilience is not easy as this depends on the infrastructure system under study. It is
important to look at the ways resilience is being considered and use these as a
method to measure resilience, either qualitatively and quantitatively. Several
approaches have been proposed in this chapter to measure or compare resilience of
two infrastructure systems.
11.1 Vulnerability and Resilience
11.1.1 Vulnerability
A water supply network must ensure that the consumer obtains water when she
needs it. By extension, Fig. 11.1 shows what a customer expects from an infrastructure system or service.
The concept of vulnerability implies some risk combined with the level of social
and economic liability, and the ability to cope with the resulting event. Vulnerability
has been defined as the degree to which a system, or part of a system, may react
adversely during the occurrence of a hazardous event.
Thus people become “vulnerable” if access to resources either at a household, or
at an individual level is the most critical factor in achieving a secure livelihood or
recovering effectively from a disaster. The households with direct access to capital,
tools and equipment, and able-bodied members are the ones which can recover most
quickly when a disaster strikes. As such, the most vulnerable people are the poorest,
who have little choice but to locate themselves in unsafe settings.
11.1.2 Resilience of Systems
When a car is moving on an uneven road surface, the car will transmit, to the
passengers, the respective shocks sustained whenever the car goes over a hump or
into a pothole. But, if the shock absorber (car damping system) is excellent
(or should we say efficient), the shocks might only be slightly noticeable. Sometimes, these passages over humps or potholes are even enjoyed by children as they
slowly return to a more stable position. This is possible because the car springs are
306
11 Infrastructure Resilience