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Introduction to
Environmental Geology
What is Environmental
Geology?
 the
application of geological data and
information for people's needs and the
improvement of our environment
How to avoid/minimize impacts from geologic
hazards
 How to find and use resources wisely: water,
minerals, etc.
 How to dispose of waste wisely: solid, water,
etc.

Fundamental Concepts of
Environmental Geology
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Population growth
Sustainability
The earth system
Uniformitarianism
Hazardous earth
processes
•
Geology as a basic
environmental
science
Fundamental ConceptsPopulation Growth
•
Population Growth is the #1
environmental problem
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•
Why?
www.prb.org
Fundamental ConceptsPopulation Growth
•
It is impossible to support exponential
population growth with a finite resource
base
1)
Primary goal of environmental work is to
defuse the population bomb
1)
2)
Pessimistic: the earth will take care of itself through
disease and catastrophes
Optimistic: find better ways to control population
growth within the limits of our available resources
Fundamental ConceptsSustainability
•
Sustainability is the environmental objective


We are currently using most living environmental
resources faster than they can be naturally replenished
What would we need for a sustainable global
economy?
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Populations of humans in natural harmony with air, water,
and land
Energy policies that do not pollute or cause climatic
perturbations
Utilization plans for renewable resources (Recycling)
Utilization plans for nonrenewable resources
Fundamental Concepts-The
earth system
The earth system

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Understanding the earth’s systems and
their changes is critical to solving
environmental problems.
The earth itself is


an open system with respect to energy
a closed system with respect to material
How do we predict the
consequences of earth system
changes?
Understand the nature of the
system
Understand rates of change
Conduct input-output analysis
Fundamental Concepts-The
earth system
•
Feedback
•
A system response where: System
output (something happening) is a
new system input
•
Positive and negative feedback
•
Input-output analysis
Fundamental Concepts-The
earth system
1. Positive feedback-- "vicious cycle"
a. one action intensifies the next (example: erosion)
2. Negative feedback-- "self-regulating"
enables the system to reach a steady state or
equilibrium (example: stream morphology).
3. Threshold events -- No apparent changes
until threshold levels are reached (Lake
Turnover).
Fundamental Concepts-The
earth system
 Negative

Feedback
Stream
 A. Increase gradient
 B. Increases the river's velocity, which
 C. Increases the rate of erosion, which
 D. Widens and deepens channel, which
 E. Slows rivers velocity
 F. promotes deposition
 G. reduces gradient
Fundamental Concepts-The
earth system
 Example
 Lake
of threshold event
turnover
Fundamental Concepts-The
earth system
Input-output
Input

analyses
= output
Steady state: no net change
Input
< output
Input > output
Fundamental ConceptsUniformitarianism

James Hutton, 1785

“the present is the key to the past”

Geologic processes modifying our landscape
have operated in the past
 Human activity is a new geological force
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Affects the magnitude and frequency of geologic
processes
“the present is the key to the future”
Fundamental Concepts-
Hazardous Earth Processes

Some geologic hazards are inevitable
 Planning is important
 The impacts of hazardous earth processes
are enhanced by spatial concentration of
population and resources
 Should be considered in cost-benefit analysis
Fundamental Concepts-Geology as a
basic environmental science
 Geology
is a factor in every person’s
life:
 “Civilization exists by geological
consent…subject to change without
notice”--Will Durant
Fundamental Concepts-Geology as a
basic environmental science

Branches of Environmental Geology:
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Geomorphology (Geologic Landforms and
Processes)
Hydrogeology (Water and soil / rock interactions)
Pedology (Soils)
Economic geology
Engineering geology
Classical geology
Fundamental Concepts-Geology as a
basic environmental science

Environmental problems are interdisciplinary

Physical
Geography, geologic processes, hydrology, rock types, soil
types, climate

Biological
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Plants, animals, biologic conditions, spatial analysis of
biologic information
Human interest/use
Land use, economics, aesthetics, environmental law,
hazards, historical/archaeological value
Hazards & Risks
“To
know one’s ignorance is
the best part of knowledge.”
Lao Tzu, The Tau, #71
Types of hazards
• Natural
• Technological
• Mixed (natural influenced by
humans)
Types of hazards
• Condition
• Process
• Event
To predict a hazardous event
1. Historical knowledge
2. Monitoring and data gathering
3. Understanding of hazardous
process
4. Must have rules to determine
success
Risk: how safe is safe?
What is risk?
What is acceptable risk?
Depends on your VALUES
“What is our society willing to pay for our
quality of life and life style?”
Paradox of risk reduction
RISK ASSESSMENT
An attempt to assess objectively a public
health or other environmental risk
1. Source/release assessment
Likelihood and scale of a potential release of
hazardous material
2. Exposure assessment
What will reach whom
RISK ASSESSMENT
3. Dose-response assessment
To estimate the impact of exposure on human
health
4. Risk characterization
To collate all of the information in a useful way
Involves great UNCERTAINTY
Human response to hazards:
Risk and Policy
1. Modify the hazards through human
intervention
2. Redistribute the losses caused by a
hazard
3. Decrease the vulnerability (Planning)
Magnitude vs. frequency
• Usually inversely related
• Affects “hazard perception”
Disaster prediction and warning
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Location
Probability occurrence
Forecasting
Warning
– Go public
– Problems?
Catastrophe
• When a natural disaster results in damages
(people or property) that require a long
involved process of recovery
Model of recovery
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Phase 1: emergency
Phase 2: restoration
Phase 3: restoration I
Phase 4; restoration II
Phase 1: Emergency
(days)
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Normal activities stop
Search and rescue
Emergency shelter/feeding
Capital damaged or destroyed
Phase 2: Restoration
(weeks-months)
• Normal activities return but at minimal
levels
• Restoration of urban services
• Return of refugees
• Capital patched
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Phases 3 & 4:
Reconstruction I & II
(months-years)
Normal activities return to predisaster levels
Capital rebuilt (replaced)
Activities improved and developed
Capital improved beyond predisaster levels
Disaster preparedness & response improved
Effects of Selected Hazards in the U.S.
(as of 2002)
Hazard
Deaths/yr.
flood
86
occurrence
Catastrophic
influenced by potential
humans?
yes
H
earthquake
50+
yes
H
landslide
25
yes
M
volcano
1
no
H
coastal
erosion
expansive
soils
0
yes
L
0
no
L
Effects of Selected Hazards in the U.S.
(Table 4.1, p. 91)
Hazard
Deaths/yr.
hurricane
55
occurrence
Catastrophic
influenced by potential
humans?
no
H
tornado
218
no
H
lightning
120
?
L
drought
0
?
M
freeze
0
no
L