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45:211: Environmental Geography Module 11 Hazard and Risk.

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Presentation on theme: "45:211: Environmental Geography Module 11 Hazard and Risk."— Presentation transcript:

1 45:211: Environmental Geography Module 11 Hazard and Risk

2 45:211: Environmental Geography Learning Objectives Hazardous and Toxic materials –Toxic waste What is Hazard? –Natural and Anthropogenic –Hazardous places –Spatial and Time aspects

3 45:211: Environmental Geography Learning Objectives What is Risk? –Assessment, Estimation, Evaluation and Management Magnitude and Frequency analysis Geography of Risk

4 45:211: Environmental Geography Hazardous Materials Materials having one or more of the following characteristics: –Ignitability (fire hazard), Corrosiveness, Reactivity (unstable), Toxicity Each year, roughly 1,000 new chemicals are produced and distributed. –Chemical products and by-products of industry are often handled and disposed of improperly.

5 45:211: Environmental Geography Hazardous versus Toxic Toxic - refers to substances that cause acute human injury or death. Hazardous - a broader term, referring to all dangerous materials that pose a human health or environmental problem. Effects depend on level of exposure and tolerance thresholds –Thus we have quality standards/objectives

6 45:211: Environmental Geography Toxic Wastes... Cause or significantly contribute to an increase in mortality or an increase in serious irreversible, or incapacitating illness; and Pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed.

7 45:211: Environmental Geography Setting Regulations Identification of Hazardous &Toxic Materials –List often limited to current known offenders –New materials appearing all the time Setting Exposure Limits –Nearly all substances are toxic in sufficient quantities –There are species-specific thresholds –Science of detection (limits of detection)

8 45:211: Environmental Geography Hazardous Waste Dumps: The Legacy Prior to mid 1970s, hazardous waste was essentially unregulated. –Most common disposal solution was to bury or dump the wastes without explicit concern for environmental or health risks. –When sites became full or unnecessary, they were simply abandoned. In North America, there are over 25,000 sites containing hazardous wastes. –Where are they?

9 45:211: Environmental Geography What is Hazard? An event or condition with the potential for causing harm, injury or damage Severe flooding in the Red River Valley, Manitoba, 1997

10 45:211: Environmental Geography Nature of Hazards Anthropogenic - created by humans, such as: –toxic chemicals, oils spills, air pollution, etc. Natural - extreme events such as: –tornadoes, hurricanes, floods, droughts, volcanoes, landslides, avalanches, etc.

11 45:211: Environmental Geography Consequences of Hazards Health and safety (public and individual) – acute and chronic Environmental impact –damage to ecosystems –bioaccumulation –keystone species Economic losses –property damage –loss of livelihood

12 45:211: Environmental Geography What is Risk? Definition: the probability of occurrence of a hazardous event. –A measure of the likelihood of an adverse effect to health, property or the environment. In other words, exposure to the chance of loss/harm, within the context of some expected net benefit. Risk = Hazard x Exposure

13 45:211: Environmental Geography Risk Assessment What can go wrong? –Hazard identification How likely is it? –Risk estimation What are the consequences? –Risk evaluation - who or what suffers harm or injury

14 45:211: Environmental Geography Hazard Identification Those hazards which generate risk of harm or injury in a particular place or situation –Based on experience and historical records –Based on medical evidence –Event Tree Analysis –Environmental Assessment

15 45:211: Environmental Geography Risk Estimation The use of available information to estimate the probability of occurrence of a harmful event or condition –the harm to human health or the environment that may result from exposure to pollutants, toxins, or extreme “natural” events. E.g. How likely are: –Toxic spills, oil spills, chemical releases, earthquakes, tornadoes, flooding, etc

16 45:211: Environmental Geography Risk Estimation Involves... Determining likelihood of occurrence: e.g. –as based on frequency analysis of historical data

17 45:211: Environmental Geography Flood Level Data

18 45:211: Environmental Geography Return Interval Analysis Large events are increasing in frequency - a result of climate change? Large events are less frequent

19 45:211: Environmental Geography Practical Application Estimates of the magnitude and frequency of floods are used by engineers in the design of bridges, culverts, dams, and embankments, and by land-use managers to assess the hazards related to the use and development of flood plains. –This is known as the design event –But there will always be an event that’s bigger than the design event  Consequences?

20 45:211: Environmental Geography Return interval: the spatial aspects of risk

21 45:211: Environmental Geography Risk Evaluation A process that identifies the consequences associated with a hazard. –Provides a basis for decisions concerning acceptable risk, by comparing the results of risk analysis with harm criteria. E.g. air quality objectives Frozen Orange Juice!

22 45:211: Environmental Geography Risk Evaluation Do the consequences matter? –What is an acceptable level of harm? –What is judicious risk-taking? –What is the proper allocation of responsibility for risky activity? Who suffers harm from what? –Socio-economic factors –Geographical factors

23 45:211: Environmental Geography Perception of risk Everyone engages in some form of risky behaviour: –Examples? –But the perception of risk is heightened by the fear of falling victim unfairly to uncompensated loss. (A random act or occurrence)

24 45:211: Environmental Geography Risk Management Can we avoid risk? –No. Can we expose ourselves to greater risk? –Yes. By using or modifying the environment without thought, by settling on marginal lands. How can we reduce risk? –Zoning, planning, regulation, building codes, safety standards, clean up of hazardous materials

25 45:211: Environmental Geography Risk Distribution Spatially - earthquake zones, flood plains, toxic waste dumps, etc. Through time - extreme event probability Socio-economically- who suffers damage, harm and death? –Who lives near dumps and industrial plants? –Who can protect themselves from risk?

26 45:211: Environmental Geography Hazardous Places Are all places equally vulnerable? No. –Hazards are spatially distributed (they are geographical) What makes a place hazardous? –What kinds of hazards are there? Including secondary hazards (e.g. landslides triggered by earthquakes or heavy rains) –What hazards do we have here in our region?

27 45:211: Environmental Geography So, where you live matters There are different types of hazards Different levels of occurrence Do you have choices? –Socio-economic factors Environmental justice –Perception of risk The fear of falling victim unfairly to uncompensated loss.

28 45:211: Environmental Geography Hazard of Place

29 45:211: Environmental Geography Hazard of Space

30 45:211: Environmental Geography We can make matters worse... Events that are typically classed as natural may be caused or worsened by human actions. For example: –The severity (and frequency) of flooding may be exacerbated by channelisation, floodplain reclamation (infilling wetlands), deforestation and other land use changes. The Saguenay floods. Other examples?

31 45:211: Environmental Geography “Natural” disasters represent the intersection of two sets: nature and population. As the population continues to grow, so does the area of intersection, leading to costlier and perhaps deadlier disasters.

32 45:211: Environmental Geography Summary Risk assessment uses facts and assumptions to estimate probability of harm from hazardous events and conditions –Hazards are natural and human-made Risk management depends on socio- economic and political factors as well as the adequacy of scientific evidence Hazard and Risk have geographical (spatial) aspects.

33 45:211: Environmental Geography Geography of Risk: Scale Factor May 1999 Tornado, Oklahoma City


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