What Is a Natural Hazard?

A natural hazard is a natural event, extreme in some way, which hurts society and human beings -- a point made forcefully by Gilbert F. White back in the 1930s and 1940s (a geographer who pioneered much of hazards studies)

• It requires that the event intersects human society in some way -- a volcanic eruption on the Jovian moon Io is not a natural hazard, despite being natural, because it does not impinge on humans or their assets and activities
• So, a natural event must impinge on humans who are themselves or have their assets arranged in space so as to be at risk to the event

That understood, there are a few fuzzy issues (or "plot complications"):

• First, we will see again and again that natural events are often actually triggered by human activities
  • A landslide set off by years of overgrazing
  • An earthquake set off by the loading of a dam (as happened with the loading of the Oroville Dam up in Northern California: There was a 5.9 earthquake on 1 August 1975 on a hitherto-believed inactive fault)
  • A series of earthquakes set off by "fracking" practices largely in the petroleum extraction industry (hydraulic fracturing induced by pumping slurries of water, various chemicals, gels, foams, and "proppants" into boreholes to bring about rock failure/cracking and prop open the new fractures to facilitate extraction): Oklahoma has had thousands of earthquakes ≥ 3.0 M_W (and a few up to 5.8) just since 2009!
  • A drought produced by human-induced changes in vegetative cover and, hence, regional climates
  • Global climate change and its many side effects, at least partly attributable to human activities increasing the standing stock of carbon dioxide, methane, CFCs, and other "greenhouse" gasses
• Second, humans often exacerbate their own risk to disaster through their very attempts to mitigate a hazardous situation
  • By suppressing chaparral fires in montane suburban California and then confidently building in it, we may set ourselves up for a much worse conflagration as the fuel relentlessly accumulates
  • Our river flood control mechanisms, such as levées and dams, give us a false sense of security, which encourages more intense occupation of flood-plains -- making us sitting ducks when the truly extreme and expectable floods come and destroy our mitigations
• Third, both greater numbers and greater proportions of the human population are living in high risk areas
  • The juggernaut expansion of the human population simply means more people to be affected by an event of a given magnitude
  • Also, there are great migration tides moving people to progressively more dangerous locales
    • Desperately poor people, largely but not exclusively in the Third World, expropriated of their land, move into very marginal lands to eke out a living or to overcrowded cities, where they form great slums in particularly unsafe locations (e.g., Haiti earthquake, Hurricane Haiyan in the Philippines, and Hurricane Katrina exposed a somewhat similar phenomenon in the social geography of New Orleans)
    • Wealthy people in the First World are increasingly using their resources to seek out pleasant amenity areas, which are often practically by definition hazard zones (e.g., California and its quakes, floods, droughts, fires, and even tornadoes and the "Hurricane Coast" of southern and eastern North America)
• Fourth, increasingly people are creating hazards of their own that in many ways are indistinguishable from the great natural hazards and require similar emergency management responses
  • Examples:
    • nuclear mishaps (e.g., Chernobyl in 1986)
    • toxic waste spills (e.g., the explosion on the BP oil rig off the Louisiana coast and the unprecedented "oil volcano" it caused in 2010)
    • toxic gas releases (e.g., Bhopal methyl isocyanate gas release in 1984)
    • terrorist incidents (e.g., 9/11)
    • major civil disturbances (e.g., the sustained protest, sometimes accompanied by rioting, following on the Rodney King beating in 1992 and then a long series of many other Black people killed disproportionately in interactions with police)
• Fifth, during a large natural (or sociogenic) disaster, there can be unpredictable cascades of interactions between and among natural and technological processes, which may trigger one another too fast for humans to cognize, let alone deal with
  • The March 2011 Tōhoku earthquake in Japan, which triggered a large series of tsunami, which exceeded the flood design capacity for the backup generators at the Fukushima Daiichi nuclear power plant, which led to a large radiation release, which will produce human deaths and illness for decades.
  • The North State floods of 1998, which caused agricultural and other chemical tanks to detach from their supports and float off and fail, allowing the unpredictable mix of chemicals to pervade the flood waters, which contaminated soils, and led to severe chemical burning of the legs of horses and other livestock when they were finally released into pastures and fields after the floodwaters receded.
  • Another example was happening just as I was preparing the F/20 class. Hurricane Isaias passed south of Puerto Rico (where its winds and torrential rain were unwelcome on the island so badly affected by Hurricane María in 2017 and coïncided with a couple of earthquakes, to boot) and then headed for Florida, which was (and again is) dealing with an accelerated growth in COVID-19 cases and deaths and trying to figure out hurricane evacuation and sheltering that maintains social distancing and masking. Optional background readings:
    • https://www.thestar.com/news/world/2020/07/30/storm-isaias-unleashes-flooding-landslides-in-puerto-rico.html
    • https://www.npr.org/2020/08/01/898124619/florida-braces-as-hurricane- isaias-heads-toward-east-coast
    • https://www.cnn.com/interactive/2020/health/coronavirus-us-maps-and-cases/
  • Another, even more recent example is provided by the 7.2 M_w earthquake that struck Haïti on 14 August 2021, eleven years after a 7.0 M_w struck Port-au-Prince and killed 300,000 people. Striking a less densely built-up and populated area, this quake has killed over 2,200 people. Complicating response to the Les Cayes quake was Tropical Storm Grace, which passed over the epicentral region two days later while people, forced out of more solid homes by the quake, faced the winds and rains in tents and under tarps. Response, restoration, and recovery are further complicated by COVID-19 and the political situation in Haïti, especially after the recent assassination of President Jovenal Moïe a week before, and bad memories of botched external aid after the 2010 quake (which among other things accidentally introduced cholera, which has since become endemic there). Optional background readings:
    • A succinct overview of these interacting disaster cascades is provided by the Center for Disaster Philanthropy: https://disasterphilanthropy.org/disaster//2021-haiti-earthquake-and-tropical-storm-grace/.
    • Time Magazine adds more detail on the concerns about post-quake and post- tropical storm disease outbreak possibilities: https://time.com/6091767/haiti-earthquake-hurricane-disease/

So, while natural hazard is conceptually easy to grasp, the concept is inherently fuzzy around the edges -- reality doesn't always line up with our tidy models.

• In this class, I will focus mainly but not exclusively on the classic "natural" hazards, with an occasional foray into technological or other social hazards. Of particular concern this semester will be pandemic hazard, due to the ongoing COVID-19 situation.
• In each case, I will present the physical geography and natural forces associated with the hazard
• Then, we'll examine the human side of the equation:
  • How do individuals perceive and cognize the risks involved?
  • Which social factors affect those perceptions?
  • How do people vary in their vulnerability to hazards?
  • What kinds of effects have great disasters had on society?
• Then, we'll look at those options that may be available to create a more sustainable resistance to hazard and a more efficient and equitable response to disaster

Here is the general plan of the course:

• The first section will familiarize you with all-hazard theoretical work on social vulnerability to hazard and disaster and we'll try to apply these ideas to the developing COVID-19 situation around us in real time
• The second part will run through several different types of hazard, including their physical mechanisms and social factors. One of these will be COVID-19.
• The last part will be devoted to your own individual and group projects

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Last revision: 08/25/21