No Such Thing as a Natural Disaster
Since we are in the midst of hurricane season and Hurricane Bill got our attention, I thought it would be a good time to discuss urban sustainability challenges with respect to natural hazards.
This entry is inspired by an iRevolution blog entitled Disaster for Techies, which does an excellent job teasing out subtle attributes of a disaster by separating the concept from its cousin—the natural hazard.
“There is a subtle but fundamental difference between disasters (processes) and hazards (events); a distinction that Jean-Jacques Rousseau first articulated in 1755 when Portugal was shaken by an earthquake. In a letter to Voltaire one year later, Rousseau notes that, “nature had not built [process] the houses which collapsed and suggested that Lisbon’s high population density [process] contributed to the toll (1)”
A short summary of definitions: A disaster is measured by the extent to which society is impacted by a hazard event (or indirectly by a changed environment), which depends on the vulnerability and resilience of a population, and supporting systems. Vulnerability describes how exposed social and natural systems are to hazards while resilience is a measure of how well systems can absorb hazard impacts and rebound.
The above quote points out that there is really no such thing as a natural disaster, so to speak about disasters in terms of phases, e.g., pre-and post-disaster phases with respect to a natural hazard event can be deceiving. The extent to which a hazard can potentially cause a disaster is governed by a complex product of past social, economic, and political processes that has ordered current social and physical infrastructure regimes, and consequently, global, regional, and local vulnerability distributions. When referring to a disaster only in relation to a specific hazard event, it becomes all too easy to focus on the event and the condition of a place at the time and not emphasize the processes that allowed the event to result in a disaster. That is, the tendency to drown-out the causes of vulnerability by focusing on the strength of a given storm (or any other natural hazard) or the geography of an impacted place (as a static phenomenon), etc. Since disasters are ongoing processes that do not depend on the actual occurrence of a hazard event, describing the phases of a situation as post- or pre-disaster obscures the social processes that are the underlying causes of disasters. To drive this point home—as a society rebuilds during a “post-disaster phase,” another disaster may be being constructed (in the processes), resulting in another pre-disaster condition.
Focusing on a specific hazard event and the static geographical situation as the causes of a disaster obscures complex issues that are deep-seated in past social processes.
To properly assess a disaster, we need to look at the processes that have resulted in a geographical situation and assess it in light of best estimates of hazard risk. For example, the industrial revolution brought people to the coastal area of the Gulf of Mexico to take advantage of an advantageous location to bring oil into the United States. The oil industry, in turn, attracted workers, increasing the population along the coast as people flocked to earn a living. (Of course there are many other processes that have caused the the population in the Gulf of Mexico—this is just an example.)
The Gulf of Mexico is subject to hurricanes and land subsidence, which makes populations in this region vulnerable. The processes above increase vulnerability as population grows and economic activity increases rates of land subsidence (fluid extraction—water/oil; build environment—buildings, homes, bridges, and levees that prevent sediment replenishment from the Mississippi River that would offset land subsidence rates), as relative sea rise further exposes the region to natural hazard risk.
When using the word “disaster,” these are the kinds of processes that we are referring to. Of course the risk of a hazard event is part of the assessment of vulnerability, which describes the potential for a disaster, but a specific hazard event itself is not a disaster.
City designs that do not view disasters as ongoing processes will not address to true underlying causes, making inhabitants vulnerable to natural hazards.