Flashcards in Lecture #4 Deck (60):
What are the 4 patterns of choice?
What does absorb mean in terms of patterns of choice?
View the risk as unproblematic/deny it
-probability deemed too low to worry
-Fate determined by capacity to absorb losses
--Ex: San andreas
What does accept mean in terms of patterns of choice?
Awareness of the hazard (no denial)
-Passive attitude: there is little that can be done
-Hazard are often view as an act of god
--Ex: Nigeria drought
What does reduce mean in terms of patterns of choice?
There is awareness of the hazard
-action is taken to reduce impacts
-reactive response and some prep
-usually people stay in place
--Ex: flooding events, snow+wind related hazards
What does change mean in terms of patterns of choice?
There is awareness of the hazard
-Radical action may be taken
-most active response
--Ex: Ausrtalian drought
What are Evocative Hazards?
Hazards that are not likely to be serious but typically evoke much public reaction
-Ex: Pesticides (increase in awareness of the potential impacts)
What are Banal Hazards?
Hazards that are known to be relatively more serious but typically evoke little public reaction
What is the amplification of risk?
Involves hazards that have a low probability as assessed by experts
-elicit strong public concern
What is the attenuation of risk?
Involves hazards that have have serious physical impact and a relatively higher probability
-elicit weak public concern
What are the 3 steps in both the amplification and attenuation of risk?
What does the Transmitter do?
Generates and sends the message about the risk
-aka media outlets
What does the Signal do?
It is the message itself
What does the Receiver do?
Its the target audience for mediate signals
-Original signal may be considerable modified by the time it is received
What is stigmatization in relation to hazards?
Negative images/thought are ascribed to places, technology or people
-Ex: Love canal chemical spill
Are impacts of hazards felt in just one place?
No, impacts can spread like ripples and often eaten well beyond the local area
What are secondary impacts?
Property values and insurance rates may change in response
What are the 5 theories that attempt to explain why some people feel that some technologies are a major concern while others are not?
What is the hypothesis for the Knowledge theory?
Greater knowledge of fatality data leads to a greater perceived threat from the technology
-Tested by education and self reported knowledge
What is the hypothesis for the Personality theory?
there is consistency between the personality type and the perceived threat from technological hazards
-Tested by questionnaires
What is the hypothesis for the Economic theory?
The healthy are more willing to take risks with technology because they may benefit more or have better access
-Tested based on annual income
What is the hypothesis of the Political theory?
Personal views toward risk are related to the political party (and policies) the people support.
-Tested by determining the political ideology of the subjects
What is the hypothesis of the Cultural theory?
The world view is correlated to how the person perceives risk
-Tested by the persons world views
What are the 3 types of world views?
What is the Hierarchal worldview?
Defines boundaries between superiors and subordinates
-Older people think this way
What is the Egalitarian worldview?
Centres on political solutions to inequality
-conflict can be alleviated with a more equal distribution of resources
What is the Individualism worldview?
Emphasizes personal freedom and choice
-Continued economic growth and private profit are keys to quality of life
Which of the 5 theories proved to have some significance?
The cultural theory was found t be the best explanation for how people perceived the risk
What is one conflict between worldview and social conflict?
-environmentalist believe in it
-economic growth advocates doubt GW
Downslope movements of rock or sediment as a result of gravity
What are the 4 classifications of landslides?
-mechanism of movement
-Type of material
-amount of water present
-speed of movement
What are the 3 mechanisms of movement?
Fall: Rock or sediment dropping off the face of a cliff
Slide: downslope movement along a discrete failure plane
Flow: Movement of particles semi-independently of one another
Rock fall definition
Mass movement is caused by a fall mechanism
-involves rock rolling down a steep slope or falling through the air
Slump fall definition
Mass movement is caused by a slide mechanism
- the failure plane is curved upward
Creep fall definition
Mass movement is caused by a flow mechanism
-Speed of movement ranges from a few millimetre to a metre annually
What are the 2 forces that affect the stability of a slop?
Driving force and Resisting force
Driving force definition
These move material downslope they are based on the weight of material from vegetation and water
Resisting force definition
These oppose downslope movement, they are based on the shear strength of the material
Whats the ratio between the resisting and the driving force
When the ratio is over 1, the slope is stable
When the ratio is under one 1 the slope is unstable
What is the equation for the factor safety?
What factors in terms of material type increase the risk of landslides?
The degree of consilidation
Presence of weakness planes
Where are slumps most common?
In unconsolidated sediment
-they are rational slides
When do transnational slides occur?
Where sediment overlays bedrock
-failure plane is at the boundary between soil and the bedrock
What happens to the driving ors when you have a steep slope?
The driving force increases
What are steep slopes associated with?
What are Moderate slopes associated with??
What are gentle slopes associated with?
What is the topographic relief?
Height of a hill or mountain above the land around it
-difference between height and base of the object
What climates are rock falls more common in?
What climate are flows and creeps more likely?
How can dense vegetation slow surface erosion?
-Roots add strength and cohesion to the slope
-Hold soil in place
-therefore deforestation can increase the frequency of landslides
How does water influence the likelihood of flows?
water can cause slumps to occur
-can erode the base of a slope and decreasing the resisting force
Which regions are at risk of rock falls, creeps and flows?
Any region with a variation of topography
-urban development, deforestation dn climate change increase the risk
What is Canada's best known landslide?
The Frank Slide
-Killed 76 people
-Created a lake
-Blocked highways and railroads
How many people per year in NA are killed by landslides?
What are the natural service functions of landslides?
-Development of new habitats in forests and aquatic ecosystems
-Increase in biodiversity
-Transport sediment with valuable minerals
What are the 2 leading human causes for the increase in landslides?
What is timer harvesting ?
clear cutting and the construction of logging roads can cause landslide in geologically unstable areas
-lack of surface vegetation can increase erosion
What are some features of unstable slopes?
- cracks in hillside
-large boulders or talus at cliff base
What are 3 methods to prevent landslides?
1. Drainage control
2. Levelling the slope
3. Slope Support