The evaluation of vulnerability to flooding Available to Purchase

From a systems perspective, vulnerability can be defined as the relationship between a purposive system and its environment, where that environment varies over time. Which environmental perturbations are significant therefore depends upon the objectives of the system as only those perturbations that can inhibit the achievement of these objectives are significant. That system must decide whether to adjust in advance to each potential perturbation or to rely upon a recovery path when that perturbation occurs. In each case, it must then decide upon the adjustment or recovery path to adopt. In particular, the basic resources available to a household are time and energy where the rates at which these can be directly or indirectly, through earning income, converted to consumption are crucial. Perturbations can reduce the energy available as well as reduce the efficiencies with which time and energy can be converted to income.