Natural Hazards Analysis - Chapter 1 pptx

Contents Preface ...xv Acknowledgments ...xvii 1 Introduction to Hazards Analysis ...1 Objectives ...1 Key Terms...1 Issue ...2 Introduction ...2 Terminology of Hazards ...2 Views of Ex

Natural Hazards

Analysis

Reducing the Impact of Disasters

Auerbach Publications

Taylor & Francis Group

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Library of Congress Cataloging-in-Publication Data

1 Disasters Social aspects 2 Emergency management 3 Preparedness 4

Community organization 5 Disasters—Risk assessment 6 Risk management I

Contents

Preface xv

Acknowledgments xvii

1 Introduction to Hazards Analysis 1

Objectives 1

Key Terms 1

Issue 2

Introduction 2

Terminology of Hazards 2

Views of Extreme Natural Events as Primary Causes of Disasters 6

A Changing Hazard Paradigm 7

Hazards Analysis 9

Hazard Identification 10

Vulnerability Analysis 10

Risk Analysis 11

Linking Hazards Analysis to Risk and Comprehensive Emergency Management 12

Communicating Risk from a Hazards Analysis 15

Community Involvement in Hazards Analysis 17

Values in Community Engagement 18

Human Social and Cultural Heritage Elements 18

Protective Actions 18

Constructed and Physical Environment 18

Conclusion 19

Discussion Questions 22

Applications 23

Web Sites 23

References 24

2 Hazard Identification 29

Objectives 29

vi  Contents

Key Terms 29

Issue 30

Introduction 30

Hazard Identification Process 31

Organizing a Hazard Identification Team 33

Creating a Community Profile 33

Social, Physical, and Environmental Assets 34

Environmental or Natural Assets 35

Social Environment 37

Built Environment 37

Infrastructure 38

Critical Facilities 38

Economic Activities 38

Mapping Community Assets and Hazards 39

Interdependence of Communities 41

Identifying Community Problems 42

Problem-Solving Process 43

Problem Solving in an Ill-Structured Environment 46

Decision Traps 47

Conclusions 47

Discussion Questions 48

Applications 48

Hazard Web Sites 49

Maps 49

References 49

3 Modeling Natural Environmental Hazards 51

Objectives 51

Key Terms 51

Issue 52

Introduction 52

The Role of Hazard Modeling in Hazards Analysis 52

Linking GIS and Environmental Models 55

Nature and Types of Models 57

Dynamic 57

Combination 57

Deterministic 58

Probabilistic 58

Hazard Models 59

HAZUS-MH Model 59

HAZUS-MH Analysis 61

Case Study: Data Sources for Flood Modeling 62

Assessing Hazard Models 65

Contents  vii

Quality 65

Timeliness 68

Completeness 69

Data Accuracy, Resolution, and Availability 70

Advantages and Disadvantages of Hazard Models 71

Hazard Profiles 73

Type of Hazard 74

Sources of Hazard Information 74

Frequency of Occurrence 75

Magnitude 76

Location and Spatial Extent 76

Duration 76

Seasonal Pattern 76

Speed of Onset 77

Availability of Warnings 77

Hazard Profile Sample for a Tornado 78

Description of Hazard 78

Potential Magnitude 78

Frequency of Occurrence 78

Seasonal Pattern 78

Probable Duration 78

Potential Speed of Onset 79

Identify Existing Warning Mechanisms 79

Identify Location and Spatial Extent of Potential Event 79

Conclusions 79

Discussion Questions 80

Applications 80

Web Sites 81

Avalanches 81

Coastal Storms 81

Dam Safety 82

Drought 82

Earthquakes 82

Flooding 82

Heat 83

Landslides 83

Lightning 83

Snowstorms 83

Tornadoes 83

Tsunamis 84

Wildfires 84

References 85

viii  Contents

4 Spatial Analysis 87

Objectives 87

Key Terms 87

Issue 88

Introduction 88

Definition of Spatial Analysis 88

Geospatial Data Set 89

Spatial Data Quality 92

Types of Spatial Analysis 95

Queries 95

Measurements 96

Transformations 97

Buffering 98

Descriptive Summaries 99

Optimization Techniques 99

Hypothesis Testing 99

Spatial Data Visualization 100

Choropleth Maps 102

Conclusions 104

Discussion Questions 105

Applications 105

Web Sites 105

References 106

5 Risk Analysis: Assessing the Risks of Natural Hazards 107

Objectives 107

Key Terms 107

Introduction 108

The Process of Risk Analysis 108

What Is Risk? 109

Quantitative Analysis of Risk 110

Qualitative Representation of Consequence 111

Views of Risk 111

Using Historical Data in Determining Risk 114

The Need for Complete Accurate Data for Decision Making 115

Using Technical Data in Decision Making 116

Indicators of Direct and Indirect Losses 117

Issues in Risk Analysis 119

Changes in Disaster Frequency 119

Availability of Essential Data 119

Depth of Analysis 121

Dealing with Uncertainty 123

Relative Ranking of Risks 123

Contents  ix

Priority Rating 126

Acceptable Risk 127

Risk Benefits 127

Determining Risk Acceptability 128

Personal 128

Political/Social 128

Economic 129

Risk Strategies 129

Accept the Risk 129

Extremely Low Likelihood of Risk 129

Mandatory Risk Level 130

Discussion Questions 130

Applications 131

Web Sites 131

References 131

6 Social, Economic, and Ecological Vulnerability 135

Objectives 135

Key Terms 135

Introduction 136

Approaches to Vulnerability 136

Dimensions of Vulnerability 139

Social and Human Vulnerability 140

Economic Vulnerability 141

Environmental Vulnerability 142

Measuring Vulnerability 144

Indicators of Social Conditions 144

Indicators of Economic Conditions 147

Indicators of Environmental Conditions 148

Methodological Issues 150

Weighting, Data Availability, and Accuracy 151

Multiyear Analysis 152

Interdependence of Social, Economic, and Ecological Capital 153

Discussion Questions 154

Applications 154

Web Sites 154

References 155

7 Risk Communication 159

Objectives 159

Key Terms 159

Issue 160

Introduction 160

x  Contents

Risk Communication 161

The Risk Communication Process 162

Barriers in Risk Communication 163

Target Audience of Risk Communication 166

Risk Communication Tools 167

Communicating Risks with Maps 167

Figures 169

Community Engagement 172

Risk Communication Myths 173

Managing Risks 175

Decision Making 176

Community Engagement in Hazards Analysis 177

Stakeholder Involvement 180

Ethics and Decision Making 182

Legal Issues in Decision Making 184

Indemnification 186

Acknowledging Risk as a Part of Risk Communication 186

Learning as a Part of Risk Communication 187

Discussion Questions 188

Applications 189

Web Sites 189

References 189

8 The Hazards Risk Management Process 193

GREG SHAw Objectives 193

Key Terms 193

Issue 194

Introduction 194

Terminology 195

Risk Management 197

Hazards Risk Management Framing Questions 200

Framework for Hazards Risk Management 201

Components of the Hazards Risk Management Process 202

Communicate and Consult (A Continual Component of the HRM Process) 202

Monitor and Review (A Continual Component of the HRM Process) 203

Step 1: Establish the Context 203

Organizational/Community Context 203

Stakeholder Involvement 204

Objectives 204

Step 2: Identify the Hazards 205

Contents  xi

Comprehensive Hazard Identification 205

Hazard Identification Strategy—Organization/ Community Resources 205

Hazard Identification Strategy—Web Resources 205

Categorizing Hazards 206

Step 3: Assess the Hazard Risk 206

Hazard Risk Assessment Strategy 206

Step 4: Sort the Hazards by Risk Magnitude 207

Sorting Strategies 207

The Use of Expert Judgment 208

Step 5: Analyze the Risks from Each Hazard 208

Hazards Risk Analysis Strategy 208

Categorizing the Hazard Risk 209

Step 6: Group and Prioritize the Hazard Risks and Consider Risk Management Interventions 209

Grouping and Prioritizing Strategy 209

Consider Hazard Risk Element Interventions 210

Application of the Hazards Risk Management Process 211

Overview 211

Step 1: Establish the Context 212

Organizational/Community Context 212

Stakeholder Involvement 212

Objectives 213

Step 2: Identify the Hazards 213

Step 3: Assess the Hazard Risk 213

Hazard Risk Assessment Strategy 213

Step 4: Sort the Hazards by Risk Magnitude 214

Step 5: Analyze the Risks from Each Hazard 214

Step 6: Group and Prioritize the Hazard Risks and Consider Risk Management Interventions 215

Grouping and Prioritizing Strategy 215

Consider Hazard Risk Element Interventions 215

Hazards Risk Management and Comprehensive Risk Management 217

Discussion Questions 217

Applications 218

Web Sites 219

References 219

9 Planning for Sustainable and Disaster Resilient Communities 221

GAVIN SMItH Objectives 221

Key Terms 221

Introduction 223

xii  Contents

Sustainability, Disaster Resilience, and Hazard Mitigation Planning 223

The Hazard Mitigation Planning Policy Framework 229

The Hazard Mitigation Plan 230

The Power of Plan Making: Tools and Process 235

The Planning Process: Building Stakeholder Capacity to Confront Hazards 236

Discussion Questions 243

Applications 244

You Be the Planner 244

Web Sites 244

References 244

10 Disaster-Resilient Communities: A New Hazards Risk Management Framework 249

Objectives 249

Key Terms 249

Introduction 250

Current Hazard Mitigation Policies 250

A New Hazards Risk Management Policy Framework 253

Expand Hazards Analysis to Include Sustainable Development and Disaster-Resilient Themes 254

Use Risk Assessment Findings to Guide Land-Use Planning and Action: Assessing Current and Future Vulnerability 255

Assess Hazard Risk Management Policies, Programs, Plans, and Projects: Building Local Capacity and Self-Reliance 255

Balancing Incentives and Penalties Affecting Human Settlement Pattern Adjustments: A Critical Look at Existing Hazard Mitigation Programs 256

Policy Evaluation and Modification: Assess Losses Avoided and Build Disaster-Resilient Communities 259

Recommendations for Action 260

Conduct National Assessment of Local Hazard Mitigation Plans 260

Place a Greater Emphasis on Land-Use Decisions and Human Settlement Patterns 261

Establish a Robust Training and Capacity-Building Approach 261

Provide Benefits to Communities that Develop Comprehensive Plans 262

Comprehensive Hazards Risk Management Benefits from the Involvement of Professional Land-Use Planners 262

Facilitate the Use of Planners as Agents of Social Change and Policy Learning 263

Include Hazards Analysis in Planning for Climate Change 264

Discussion Questions 265

Contents  xiii

Application 265You Be the Policy Analyst 265References 265

Preface

Damage and economic impacts of natural and man-made disasters have been ing at exponential rates over the past few decades The magnitude of these disasters and our global interconnectedness have grown to the point where disasters may have regional, national, and even global economic consequences We have attempted to reduce risks to human, economic, and environmental infrastructure, but at the same time continue to develop vulnerable geographic coastline areas of the world Our communities are more vulnerable today than ever before to natural and human-caused disasters Communities that are subject to such high degrees of risk can only achieve sustainable social and economic development through appropriately informed planning, protection, mitigation, and recovery strategies that are based on research that integrates our complex social, economic, and environmental systems

grow-Natural Hazards Analysis: Reducing the Impacts of Disasters examines the

haz-ards analysis process but also provides a broad view of how we use the outcomes

in preparedness, response, recovery, and mitigation activities of the emergency management process Specifically, this book demonstrates how we utilize a hazards analysis for developing hazard mitigation strategies and the broader hazards risk management process Further, the roles of problem solving, decision making, and risk communication are stressed in this text as a means of ensuring that we accu-rately identify problems associated with hazards and the risks that they present and make quality decisions associated with these risks The risk communication process

is also addressed, and the importance of engaging stakeholders in ensuring that risks are understood is stressed The key is that hazards analysis is not an isolated process, but one that involves public officials and employees, the public, and the media, and that care is taken to ensure that all appreciate the risks that confront our organizations and communities

Social and natural scientists currently apply various technological tools to acterize hazards, but we still have a limited understanding of the social, economic, cultural, and environmental impacts of hurricanes, floods, earthquakes, chemical spills, or terrorist incidents The fundamental processes that the natural, social, and engineering sciences have to consider include a very dynamic landscape, which requires policies that promote adaptation and resiliency rather than a philosophy of

char-xvi  Preface

control Policies and decisions associated with rebuilding after Hurricanes Katrina and Rita demonstrate the difficulty in understanding risk and vulnerability in changing natural, social, and built environments

The key to understanding the dynamics of risk and vulnerability to disasters is through a comprehensive hazards analysis A cross-disciplinary approach is recom-mended in this text to clarify how to deal with uncertainty in ever-changing social, economic, and natural landscapes in disasters The intent of this text is to dem-onstrate how we use outputs from environmental models, the tools of geographic information systems (GIS), spatial analysis, and remote sensing to clarify the rela-tionships between human, economic, and natural systems

We stress that a better understanding of our vulnerabilities will facilitate munity planning, hazard mitigation, and our ongoing rebuilding, restoration, and recovery efforts Few books take the broad-based approach, as recommended

com-in Natural Hazards Analysis: Reduccom-ing the Impacts of Disasters, com-in examcom-incom-ing the

impacts of disasters on our natural, social, cultural, and economic environments This broader view will help us to build sustainable communities

The goals of the book are:

1 To provide a framework for understanding the nature and consequences of ral and human-caused hazards on the natural, built, and human environments

2 To examine strategies that may be taken at the individual, organizational, community, or regional levels to reduce the adverse consequences of disasters and foster sustainability

Primary Learning Objectives

To be able to explain the role and uses of hazards analysis in organizational N

decision making and public policy

To be able to characterize the nature of hazards and the factors that affect themN

To be able to explain the nature and types of models used to characterize N

natural and technological hazards

To be able to explain how we measure potential and actual direct and indirect N

social, economic, and environmental impacts of disasters on families, nesses, and communities

busi-To be able to describe the role and uses of spatial analysis and geographic N

information systems in hazards analysis

To be able to clarify how individuals perceive risk and how risk perception N

influences decision making at the individual, business, and community level

To be able to explain how risk management and hazard mitigation strategies N

could reduce or minimize losses from disasters

To be able to explain the role of hazards analysis in building and fostering N

sustainable communities and business organizations

Acknowledgments

This text is an outgrowth of my teaching and research efforts over the past ten years

at Louisiana State University (LSU) I began teaching Environmental Hazards Analysis for both graduate and undergraduate students at LSU in 1996 and used in this class my experiences from conducting hazards analysis projects for local, state, and federal agencies as well as private-sector chemical processing operations To say the least, I would not have been able to initiate this text without the support from the Federal Emergency Management Agency (FEMA), the U.S Environmental Protection Agency (EPA), the National Oceanographic Atmospheric Administration (NOAA), the National Science Foundation, the Organization of American States, Louisiana Office of Emergency Management (LA OEP), the Louisiana State Police, the Louisiana Department of Environmental Quality (DEQ), and numerous state and local government agencies throughout the United States I want to thank Ms Mary Lee Eggart, who is the graphic artist in the Department of Geography and Anthropology at LSU for her creative contribution to the graphics in this text

I especially want to acknowledge and thank my colleagues Gavin Smith at the University of North Carolina and Greg Shaw at George Washington University (GWU) for their contributions in Chapters 8 through 10 Gavin saw first hand how a quality hazards analysis is critical in community planning during recovery efforts following Hurricane Katrina His ability to clearly articulate hazard mitiga-tion initiatives is based on a sound understanding of hazards and decision making Greg has taught classes at GWU and developed several courses for FEMA’s Higher Education Project associated with hazards risk management His insights into the nature of organizational risk are seen throughout this text, as well as his view that hazards risk management must fit within an organization’s short- and long-term strategies We thus see that hazards analysis is part of community and organiza-tional decision making as it relates to understanding risk, especially from hazards, and that organizational and community policies are critical in reducing our vulner-abilities to the adverse impacts from disasters

I would like to also acknowledge my social science colleagues at LSU, the University of New Orleans (UNO), and throughout the United States in reori-enting my view of the interactions between social, economic, and environmental

xviii  Acknowledgments

systems For many years, I examined how human actions impacted our physical landscapes As a result of my work with Shirley Laska and Kristina Peterson at UNO, and Breda Phillips at Oklahoma State University, and families in the Grand Bayou community located twenty-five miles south of the City of New Orleans, I became more aware of how hazards associated with natural systems and the envi-ronment impact on individuals, families, and communities Community mem-bers were engaged in our hazards analysis process from day one and participated jointly with us in expanding our understanding of vulnerability and communicat-ing our findings at numerous professional meetings throughout the United States Community engagement and open risk communication are stressed in this text and included as a vital part of the hazards analysis process

John C Pine

Director, Disaster Science & Management

Louisiana State University

1 Chapter

Introduction to

Hazards Analysis

Objectives

The study of this chapter will enable you to:

1 Clarify why hazards analysis is so important in reducing losses from disasters

2 Compare and contrast hazards terminology

3 Explore the view of extreme hazard events as a primary cause of disasters

4 Explain alternative hazard paradigms that include social, political, economic, and environmental systems

5 Define the hazards analysis process and its links to hazards risk management and comprehensive emergency management

6 Explain why communicating risk is so critical in a hazards analysis

2  Natural Hazards Analysis: Reducing the Impact of Disasters

Over the past twenty-five years, we have seen escalating costs associated with the direct economic impacts of natural disasters Although the number of injuries and causalities has been dropping in recent years, property damage has increased dramatically (Abramovitz 2001; Mileti 1999) Mileti notes that disaster losses have been increasing and will likely continue in the future (1999) He sees that damages will grow to an average of $50 billion annually—about $1 billion per week Some experts believe that this is a relatively conservative estimate of losses, since there is little inclusion of indirect losses (i.e., loss of jobs, market share, productivity, etc.).The rising cost of disasters has also paralleled the movements of our popula-tion to coastal regions, thus increasing their vulnerability to hazards In addition,

we have seen widespread adverse impacts of disasters in the form of massive placement, economic losses, and suffering from all parts of our society Hurricane Katrina clearly demonstrated that many members of our community suffered from the flooding and storm surge Poststorm after action reports have consistently noted that governments at all levels were ill prepared to deal with such a massive disaster.This book challenges us to first examine the nature of our community and the hazards that could impact our social, economic, and ecological systems We go further to also identify an approach to develop a broad-based hazard risk manage-ment strategy to reduce risk and mitigate losses This book provides a roadmap for clearly identifying hazards, our vulnerabilities, and both risk management and community-wide strategies for building sustainable communities

dis-Terminology of Hazards

Individuals interested in hazards and risks are exposed to multiple definitions of key terms such as “hazards,” “disaster,” “risk assessment,” and “hazards analysis.” Often,

Introduction to Hazards Analysis  3

many of the terms are used interchangeably and, arguably, correctly or incorrectly Many experts in the risk field have addressed the “terms” problem For example, Kaplan describes two theorems of communication, which explain the confusion resulting from the different and often conflicting definitions of terms used in risk analysis and assessment (1997) The theorems state the following: Theorem (1), 50% of the problems in the world result from people using the same words with different meanings; Theorem (2), the other 50% comes from people using different words with the same meaning This confusion has led organizations such as the Federal Emergency Management Agency (FEMA), the International Association of Emergency Managers (IAEM), the U.S Environmental Protection Agency (EPA), and other federal agencies to increase the professionalism in the field by recognizing the need for a common set of definitions

Hazards refers to a potential harm which threatens our social, economic, and natural capital on a community, region, or country scale Hazards may refer to many types of natural (flood, hurricane, earthquake, wildfire, etc.), technological (hazard-

ous materials spill, nuclear accident, power outage, etc.), or human-induced events

(biochemical, bombing, weapons, mass destruction, terrorism, etc.) Compounded hazards are those that result from a combination of the above hazard types, such

as urban fires resulting from earthquakes, failures of dams or levees resulting from flooding, or landslides resulting from wildfires and heavy rains

FEMA describes hazards as “events or physical conditions that have the tial to cause fatalities, injuries, property damage, infrastructure damage, agricul-tural losses, damage to the environment, interruption of business, or other types

poten-of harm or loss” (1997) A hazard may be measured by its physical characteristics, likelihood, or consequences For example, many coastal communities experience flooding Water from heavy rains, levee breach, or dam break would be the source

of the hazard The likelihood could be considered a low risk or not likely; it could

be a medium risk or one that has a high likelihood of occurring A hazard has the potential to cause fatalities, injuries, property damage, infrastructure or agricultural loss, damage to the environment, interruption of business, or other types of harm.Cutter notes that hazards evolve from interactions between natural, human, and technological systems (2001) but are also characterized by the areas of their origin For example, the hazard may arise from a hurricane, but flooding may be magnified not only from excessive rainfall but also by long term nonsustainable agricultural or forest practices Since a disaster could evolve from the interactions between social, natural, and technological systems, the classification of a complex hazard could be difficult As a further illustration of the difficulty in classifying disasters, a hurricane or flood occurring in a community might also lead to an acci-dental release of a hazardous chemical from a container in flood waters In this case,

we have the potential of two disasters–one natural and the second human-caused

or technological in nature Cutter suggests that we view hazards within a broader social, political, historic, economic, and environmental context to fully appreciate how hazards can cause damage to community resources

4  Natural Hazards Analysis: Reducing the Impact of Disasters

The United Nations defines a disaster as, “a serious disruption of the ing of society, causing widespread human, material, or environmental losses which exceed the ability of affected society to cope using only its own resources” (United Nations 1992)

function-All disasters, small or large, are the result of a hazard being realized There is a caveat to this definition, however, in that the realized hazard must overwhelm the response capability of a community to be considered disastrous (FEMA 1997).Pearce (2000) suggests that any definition of disaster must reflect a given local-ity’s capacity to respond She goes on to state that the hazard event must be unusual and that the social, economic, political, and ecological impacts must be significant She defines disasters:

A disaster is a non-routine event that exceeds the capacity of the affected area to respond to it in such a way as to save lives; to preserve property; and to maintain the social, ecological, economic, and political stability

of the affected region (p 87)

Disasters are measured in terms of lives lost, injuries sustained, or property damaged and must be distinguished from routine emergency events that can result

in property damage or fatalities For instance, a house fire may require a response

by a jurisdiction’s fire department and result in loss of life or property However, as fires are common emergency occurrences, they are managed by local response agen-cies and are normally not considered a disaster For a fire to be considered a disaster,

it must overwhelm the capacity of the local responders

Common breakdown of hazards include atmospheric climatic hazards such as rain, lightning, wind and dust storms, hailstorms, snow avalanches, heat waves, snowstorms, and fog (Bryant 2005; FEMA 1997; Hewitt and Burton 1971) They also include geologic and seismic hazards such as landslides, avalanches, land subsidence, erosion, earthquakes, tsunamis, volcanic activity, and shifting sands Hydrologic hazards make up the third type of natural hazard and include flood-ing, storm surges, coastal erosion, waves, sea ice, and sea level rise Hewitt explains that compounded hazards include tropical cyclones, thunderstorms, whiteouts, tor-nadoes, rain and windstorms, blizzards, drought, freezing rains and wildfires; all combine several natural hazards and are not just the result of a single hazard.Not all hazards result in disasters, for a hazard event could decrease potential damaging impacts so as to minimize losses (Gruntfest et al 1978; Hewitt and Burton 1971; Lindell and Meier 1994) The rate or speed of onset of the event could give communities notice needed to minimize deaths and injuries by order-ing an evacuation for a flooded area Availability of perceptual cues (such as wind, rain, or ground movement) provide notice of a pending disaster The intensity of a disaster could vary spatially so as to have damage impacts in areas with no social

or economic impacts Technology such as weather radar allows us to see where a heavy storm is moving so as to provide warning to the local area The areal extent

Introduction to Hazards Analysis  5

of the damage zone or its size (geographic area influenced) and its duration could influence any damaging impacts and the community’s capacity to deal with the hazard event Wind damage from a tornado could be limited to nonpopulated areas and not cause injuries or property damage Finally, the predictability of the event or notice of occurrence is also critical in allowing those affected by the event

to seek safety

Despite our efforts to reduce our vulnerability to disasters, we see that erty losses, deaths, and injuries continue to increase Numerous studies have docu-mented that increased losses are growing because (Abramovitz 2001; Mileti 1999):

1 Population growth occurs in high hazard areas

2 Marginalized land is being developed, making us more susceptible to ard impacts

3 Larger concentrated populations in urbanized areas increase the potential for human and property loss; people are less familiar with hazards in their sur-roundings; growth may not be ecologically sustainable; more buildings and infrastructure may be damaged if an event occurs

4 People are not impacted by hazards equally; economic disparities cause large numbers of impoverished people to be at risk

5 Immense potential for loss as sea levels rise; weather and climate patterns will change

6 Political unrest can directly cause loss (e.g., civil war) and/or make a region more susceptible to hazard impact due to lack of preparedness and/or inabil-ity to cope

7 More property is at risk to hazards, but preparedness and mitigation sures minimize loss of human life

mea-The terms “risk” and “hazard”’ are often used interchangeably and tently Different interpretations come from the fact that among emergency man-agers, risk managers, urban and regional planners, insurance specialists, and lay people, the meanings of the words have evolved independently and are used many different ways These definitions can even be in conflict with each other For exam-ple, it is not uncommon for the word risk to be used informally in a way that means

inconsis-“venture” or “opportunity,” whereas in the field of risk management the tion is always negative (Jardine and Hrudley 1997) However, even among risk managers, the exact definition of risk varies considerably (Kedar 1970)

connota-The risk of disaster is typically described in terms of the probabilities of events occurring within a specified period of time, e.g., five, ten, or twenty years, a spe-cific magnitude or intensity (or higher), or a range such as low, medium, or high risk For example, the risk of floods is commonly described by FEMA in terms

of 100- and 500-year floods, indicating the average frequency of major flooding over those periods of time and the maximum area that has been inundated each time Risk has the common meaning of danger (involuntary exposure to harm),