Module 1 Flashcards
Earths processes and energy sources are driven by:4
- Earth processes driven by Earth’s internal heat: portions of the Rock Cycle, plate tectonics, earthquakes, volcanic eruptions, tsunamis
- Earth processes driven by insolation: portions of the Rock Cycle, hydrologic cycle, atmospheric and oceanic circulation, severe storms, river floods, coastal erosion
- Earth processes driven by gravity: landslides, snow avalanches, river flow
How to classify Natural Hazards?5
- Geologic – earthquakes, volcanic eruptions, tsunamis, landslides; links to Rock and Tectonic Cycles (see Fig. 1.8, p. 11)
- Atmospheric – tornadoes, hurricanes, heat waves; droughts, blizzards; links to the Hydrologic Cycle (see Fig. 1.9, p. 12)
- Hydrologic – river floods, sea-level rise, coastal flooding; links to the Hydrologic Cycle
- Biologic – epidemics of plant, animal, and human diseases, wildfires, mass extinctions; links to Biogeochemical Cycles (see p. 12) and food webs
• Technological/ social hazards and disasters: are directly generated by humans without the interaction of natural processes
- examples include automobile and train wrecks, airplane crashes, human induced explosions (e.g. Halifax explosion, 1917)
• Hazards are commonly linked to each other as well as the environment in which they occur (e.g. earthquakes and tsunamis, or volcanic eruptions and lahars
Define:
Hazard
Risk
Exposure
Vulnerability
Coping Capacity
• Hazard – probability that a specific damaging event will happen within a particular period of time
• Risk – derives from a combination of hazards, exposure, vulnerability, coping capacity (see Fig. 1.4, p.7)
• Exposure – overlap of a hazardous process with human populations and/or infrastructure
• Vulnerability – susceptibility of human populations to a hazardous event
-damage to infrastructure; loss of life -loss of livelihoods; physical displacement; psychological impacts
• Coping capacity – ability of populations to respond to and/or reduce negative impacts of a hazardous event (i.e., mitigation)
4 parts to ‘Disaster Risk’
Hazard
-probability and severity
Exposure
-structures, population, economy
Vunerability
-physical, social, economic, environmental
coping Capacity and Measures
-physical planning, social capacity, economic capacity, management
Estimating risk:
Risk=(equation)
Likelihood x Cost
If the likelihood or cost are very low, the risk will likely be low. Similarly, if the likelihood or cost is very high, the risk will also be high.
Likelihood defined
Cost defined
.Likelihood: An estimate, based on previous events, referring to the chance of a hazard happening in a specific amount of time
• Cost: Refers to the impact of a particular hazard • damages to property and infrastructure ($)
• # persons seriously injuries and fatalities (difficult to quantify)
If the likelihood or cost are very low, the risk will likely be low. Similarly, if the likelihood or cost is very high, the risk will also be high.
What 5 factors can individually make something be defined as a disaster in canada?
- 10 or more people killed
- 100 or more people affected/injured/infected/evacuated or homeless
- an appeal for national/international assistance
- historical significance
- significant damage/interruption of normal processes such that the community affected cannot recover on its own
What is the overarching structure for natural distaters in Canada? The name
Canada’s Emergency Management Framework
Define natural catastrophy
Catastrophes are associated with greater numbers of casualties (injuries and deaths) and destruction of infrastructure
• the event has consequences well beyond the area/region directly affected by the event
• recovery will demand large and long-term expenditures of time, human effort, and money
Rank Natural disasters in terms of caused deaths per year in Canada and US
Permafrost thaw River floods Snow avalanches Landslides Coastal Erosion Earthquakes
River floods 100(deaths/year) High(catastrophe potential) Earthquakes >50 High Landslides 30 Low Snow avalanches 20 Low Permafrost thaw 0 High Coastal Erosion 0 Low
-Landslides/avalanche low because people tend to not live in areas/avoid areas most effected
-permafrost thaw is possibly based on potential, growing issue only found in less populated climates
-rivers tend to have high populations in the general area
Rivers:
-significant displacement of people while housing and other is being rebuilt
-mortality
-need for outside help
-damaged infrastructure because we love to put a lot of economically important areas in floodplains
-potential for diseases rises significantly(cholera)
Permafrost:
-permafrost has been degrading from 1970s
-degassing of permafrost and its long-term effect on climate(tertiary)
-terrain instability because as permafrost melts its strength to hold soil is depleted
-spatial scale of change: rivers are isolated to a watershed, yet permafrost is circumpolar in nature
• Naturally occurring Earth processes become ____________ when they threaten human populations
hazourdous
NATURAL DISASTER OR CATASTROPHE? EXPLAIN WHY
Assiniboine and Red River floods, 2011
the Manitoba government declared a province-wide state of emergency, issuing evacuation notices for several municipalities along the Assiniboine River
2011 flood featured the highest water levels and flows in modern history across parts of Manitoba and Saskatchewan
7,100 Manitobans were displaced from their homes, with 2,700 still evacuated at the end of the year
Flooding affected three million hectares of farmland and forced the closure of 850 roads, including parts of the Trans-Canada Highway; > $1 billion dollars to fight flood and for compensation
1 reported fatality
. Has historic significance: highest water levels and spread ever
. significant number of people displaced going on 6 months
. economic base of area(agricultural land) lost to flooding, possibly for multiple years
. low fatalities
. Only national aid, no need for international recovery aid
= Natural Disaster
Why is there an overall increase in natural disasters?
Why in Canada is there A decrease in lives lost, but an increase in economic losses…why
Canada’s vulnerability to disasters is increasing. There is a focus on recovery and some mitigation efforts in Canada.
Why is there an overall increase in natural disasters?
Why in Canada is there A decrease in lives lost, but an increase in economic losses…why
because of growing population living in dangerous areas
Canada’s vulnerability to disasters is increasing. There is a focus on recovery and some mitigation efforts in Canada.
- takes considerable economic resources to bring ourselves back to the pre-event state
- could also be higher use of emergency services and healthcare
From 1990-2010, the most common natural disasters in Saskatchewan were ______ (42%), _____(23%), and _______(8%).
droughts, floods, wildfire
Magnitude
Frequency
Reccurence Interval
refers to the strength and sometimes the intensity of the hazard.
Frequency: refers to how often the event is likely to occur
• Recurrence interval: estimate of the interval of time between events of a certain intensity or size
There are several different quantitative scales used to compare the magnitude of events:
- Richter scale vs. moment magnitude vs. Mercalli intensity scale for earthquakes
- Volcanic explosivity index (VEI)
Mercalli intensity scale: measures…
how much the ground shakes during earthquakes
Describe the magnitude-frequency relationship
There is generally an inverse relationship between magnitude and frequency, the larger the magnitude, the less frequent the event.
.Small magnitude has high frequency
.high magnitude has low frequency
Define:
Duration=
Extent=
Spatial Predictibility=
Duration: refers to the length of time the event lasts
hours, days, weeks, months
Extent: refers to the size of region affected by the event (e.g. local, regional, national, global)
• hurricanes and tornadoes occur at different spatial scales
Spatial Predictability: refers to where hazards are located or centered (spatial) and to some extent, whether or not the hazard can be predicted
ex:.hurricanes never form between 10 degrees North and South
-move east to west and then up north because of wind patterns
.we know the special circumstances that need to be present to trigger a tornado
-then can be communicated to people in area
Describe “speed of onset” and the three speeds:
Speed of onset: refers to the speed at which the peak of the hazard arises; may be rapid, moderate, or slow
1• rapid onset: develop with little warning and strike rapidly(e.g. earthquakes, flash floods)
2• moderate onset: develop with some warning (e.g. volcanic eruptions, floods)
3• slow onset: take years to develop (e.g. drought, disease epidemics)
• The speed of onset affects the time available to predict the event and to evaluate those at risk accordingly (e.g. Mount Pinatubo, 1991); predictions at the onset of the climactic eruption led to the evacuation of tens of thousands of people from the surrounding areas
Natural Hazards are reccurent events
Natural hazards are recurrent events
• To evaluate risk, we need to understand the geologic history of a region, often extending back hundreds or thousands of years
• We can look to maps, aerial photographs, and satellite images for recent changes in the landscape
• We often need to examine the geologic record for further evidence of past events (e.g. tsunami, landslides, lava flows)
Describe an Event Profile
Event profiles are a common way of comparing different natural hazards and the physical processes or attributes that they share:
- speed of onset, duration, magnitude, areal extent, spatial predictability, frequency
- good for comparing hazards
ex: Tsunami vs. Volcanic Eruption
- enourmous vs. small
- rapid vs. slow
- short vs. long
- widespread vs. limited
- predicatable vs. predictable
- rare vs. frequent
Short and Long Term Impact: 3 types of effects
Natural hazards can have primary, secondary, and tertiary effects:
• Primary effects - occur as a result of the natural process itself (e.g. building collapse due to an earthquake)
• Secondary effects - occur only because a primary effect has caused them (e.g. fires ignited because of earthquake)
• Tertiary effects - long-term effects caused by the event (e.g. cholera epidemic after an earthquake)
