Introduction to Environmental Geology. What is Environmental Geology? the application of geological data and information for people's needs and the.

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

• Population growth• Sustainability• The earth system• Uniformitarianism• Hazardous earth

processes

• Geology as a basic environmental science

Fundamental Concepts-Population Growth

• Population Growth is the #1 environmental problem

• Why?• www.prb.org

Fundamental Concepts-Population 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 bomb1) Pessimistic: the earth will take care of itself through

disease and catastrophes2) Optimistic: find better ways to control population

growth within the limits of our available resources

Fundamental Concepts-Sustainability

• 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?• 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

• 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 changeConduct 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 systemExample of threshold event

Lake turnover

Fundamental Concepts-The earth system

Input-output analysesInput = output

Steady state: no net change

Input < outputInput > output

Fundamental Concepts- Uniformitarianism 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 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: 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 Plants, animals, biologic conditions, spatial analysis of

biologic information

Human interest/useLand 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 assessmentLikelihood and scale of a potential release of

hazardous material

2. Exposure assessmentWhat will reach whom

RISK ASSESSMENT

3. Dose-response assessmentTo estimate the impact of exposure on human

health

4. Risk characterizationTo 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

• 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

• Phase 1: emergency

• Phase 2: restoration

• Phase 3: restoration I

• Phase 4; restoration II

Phase 1: Emergency(days)

• 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

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. occurrenceinfluenced byhumans?

Catastrophicpotential

flood 86 yes H

earthquake 50+ yes H

landslide 25 yes M

volcano 1 no H

coastalerosion

0 yes L

expansivesoils

0 no L

Effects of Selected Hazards in the U.S. (Table 4.1, p. 91)

Hazard Deaths/yr. occurrenceinfluenced byhumans?

Catastrophicpotential

hurricane 55 no H

tornado 218 no H

lightning 120 ? L

drought 0 ? M

freeze 0 no L