Landslide Risk Assessment – Second Edition

Contents Preface to the first edition ix
Preface to the second edition xi
Scientific notation xiii
1 Background to landslide risk assessment 1
1.1 Introduction 1
1.2 What is risk? 1
1.3 A view of risk 4
1.4 Black Swans and Perfect Storms 6
1.5 What is landslide risk? 7
1.6 Hazard and vulnerability 8
1.7 From hazard to risk 12
1.8 Categories of risk 13
1.9 Why do landslide risk assessment? 14
References 17
2 The basic elements of landslide risk assessment 21
2.1 Introduction: the risk assessment process 21
2.2 Description of intention 23
2.3 Hazard assessment 23
2.4 Consequence assessment 27
2.5 Risk estimation 31
2.6 Risk assessment and its relationship to risk evaluation and risk
management 33
2.7 Risk perception and risk communication 35
2.8 Landslide risk assessment procedures 40
2.9 Risk assessment as a decision-making tool 41
2.10 Structure of the book 42
References 44
3 Landslide hazard 47
3.1 Introduction 47
3.2 Landslide mechanisms and type 49
3.3 Landslide behaviour 52
3.4 Potential for landsliding 56
3.5 Landslide velocity 58
3.6 Landslide travel distance 60
3.7 Nature of landslide hazards 63
3.8 Landslide intensity 74
3.9 Landslide susceptibility and hazard zoning 79
3.10 Hazard models 83
3.11 Uncertainty, assurance and defensibility 84
References 88
4 Qualitative and semi-quantitative risk assessment 97
4.1 Introduction 97
4.2 Risk registers 100
4.3 Relative risk scoring 102
4.4 Risk ranking matrices 109
4.5 The FMECA approach 115
4.6 Qualitative risk assessment: an easy option? 124
References 126
5 Introduction to probability and quantitative assessment 129
5.1 Uncertainty and probability 129
5.2 Probability distributions 143
5.3 Judgement and the use of experts 171
5.4 Probability assessment and reliability methods 181
References 197
6 Estimating the probability of landsliding 205
6.1 Introduction 205
6.2 Approaches to estimating landslide probability 207
6.3 Statistical methods: the use of incident databases 209
6.4 Statistical methods: historical frequency assessment 212
6.5 Statistical methods: the use of landslide magnitude-frequency
curves 216
6.6 Statistical methods: estimating landslide exceedence probability 225
6.7 Statistical methods: estimating probability of cliff recession
through simulation models 229
6.8 Conceptual models: normalisation of base-rate frequency 236
6.9 Conceptual models: estimating probability from
landslide -triggering events 243
6.10 Conceptual models: estimating probability through expert
judgement 252
6.11 Reliability methods: estimating probability through use of
probabilistic stability analysis 267
6.12 Estimating probability: precision of pragmatism? 272
References 273
7 Exposure 281
7.1 Introduction 281
7.2 Spatial probability: stationary assets 282
7.3 Spatial and temporal probability: non-stationary assets 286
7.4 Occupancy and population models 292
7.5 Reducing exposure through landslide detection 294
References 296
8 Vulnerability 297
8.1 Introduction: multiple meanings of vulnerability 297
8.2 Physical vulnerability 299
8.3 Physical vulnerability of buildings and infrastructure 300
8.4 Human vulnerability 307
8.5 Societal and social vulnerability 311
References 316
9 Estimating the consequences 321
9.1 Introduction 321
9.2 Elements at risk 324
9.3 Using the historical record 324
9.4 Categories of adverse consequences 329
9.5 Loss of life and injury 330
9.6 Direct impact on buildings, structures and infra-structure (direct
economic costs/losses) 334
9.7 Other economic costs that may be estimated in advance 336
9.8 Intangible losses 337
9.9 Uncertain consequences 339
9.10 Consequence models 339
9.11 Multiple-outcome consequence models 359
9.12 Complex outcomes and uncertain futures 367
References 369
10 Quantifying risk 375
10.1 Introduction 375
10.2 Current annual risk 376
10.3 Cliff recession risk 381
10.4 Comparing the risks associated with different management
options 388
10.5 Individual risk 396
10.6 Societal risk 409
10.7 Statistics are signs from God? 416
References 418
11 From risk estimation to landslide management strategy 421
11.1 Introduction to landslide risk management 421
11.2 Assessment criteria 425
11.3 Risk acceptance criteria: legal frameworks 426
11.4 Acceptable or tolerable risks: the ALARP principle in the UK 427
11.5 Individual risk criteria 429
11.6 Societal risk criteria 431
11.7 Corporate risk management: major accident risk criteria 435
11.8 Applying the ALARP principle: loss of life 437
11.9 Applying the ALARP principle: economic risk 439
11.10 Environmental protection 443
11.11 Environmental acceptability 447
11.12 Corporate risk management: the risk matrix approach 447
11.13 Future uncertainty: implications for landslide management 449
11.14 Risk assessment, decision-making and consultation 452
References 453
12 Future challenges 459
12.1 Introduction 459
12.2 Quantitative risk zonation: lessons from Ventnor, Isle of Wight 459
12.3 Landslide risks and major project schedules: lessons from the
Camisea pipeline, Peru 461
12.4 Risk assessment and management of extreme events: lessons
from Fukushima, Japan 464
12.5 Landslide management and the environment: lessons from
Easton Bavents 466
12.6 Future uncertainty: valuation of environmental resources 468
12.7 Future uncertainty: global change 470
12.8 Evidence for climate change 471
12.9 Future uncertainty: climate model predictions 472
12.10 Increased rainfall 474
12.11 Sea-level change 476
12.12 Uncertainty and risk assessment 484
References 485
13 Glossary of terms 491
Index 201