Preface

Risk is a relatively new and not fully explored concept especially for different kinds of events and activities. There are many definitions of risk. And often, a scientific study or a scientific approach to the problem begins with a presentation of the author's position and the choice of the risk definition of natural, technogenic, medical, financial, and other events. This individualistic approach is difficult to avoid. Spores are carried out so far. For example, whether or not there is a risk without material damage to people.

If one of the main systematic approaches to research on hazards and disasters is their classi‐ fication, even now the concept of risk management can be considered as a new step of scien‐ tific development and a new basement for systematic investigations of danger, hazards, and disasters.

The development of the risk concept demands the promotion of the methods for risk assess‐ ment and calculation. It makes the risk theory a scientific discipline with good mathematical background. It is necessary to elaborate common approaches to risk calculation for different types of natural hazards and activities. The methods of seismic risk assessment as the most promoted ones must be spread to landslides, karst, suffusion, flooding, pollution, and other types of natural hazards and risks and also to complex and multirisk.

Arising from everyday life, gambling, finance, business, and building the risk concept be‐ came the subject for scientific research and the basement for systematic investigations of nat‐ ural and man-made hazards and disasters, medical and health problems, financial crisis, and environmental catastrophes.

In common sense, risk is the potential of gaining or losing something of value. Values, such as physical health, social status, emotional well-being, and financial wealth, can be gained or lost when taking risk resulting from a given action or inaction and foreseen or unforeseen. Risk can also be defined as the intentional interaction with uncertainty. Uncertainty is a po‐ tential, unpredictable, and uncontrollable outcome; risk is a consequence of action taken in spite of uncertainty.

In risk-analysis science, risk is considered as a measure of the probability and severity of an adverse effect to health, property, or the environment. Risk is often defined as the probabili‐ ty of the hazard event multiplied by the possible consequences. One of the most common approaches defines that risk is the expectation of the damage, or expected value of damage.

Risk analysis is the use of available information to calculate the risk to individuals, popula‐ tion, property, or the environment from hazards. Risk analyses generally contain the follow‐ ing steps: hazard identification and vulnerability evaluation.

Vulnerability is the degree of loss of a given element or a set of elements exposed to the occurrence of a natural or man-made hazard. It is expressed on a scale of 0 (no loss) to 1 (total loss).

Risk assessment is considered as the process of making a recommendation on whether exist‐ ing risks are acceptable and present risk control measures are adequate, and if they are not, whether alternative risk control measures are justified or will be implemented. Risk assess‐ ment incorporates the risk analysis and risk evaluation phases.

Sometimes, risk assessment is considered as risk calculation on the base of selected parame‐ ters and establishment of ranking risk criteria.

Acceptable risk refers to the level of human and property loss that can be tolerated by an individual, household, group, organization, community, region, state, or nation. For in‐ stance, the risk of flooding can be accepted once every 500 years, but it is not acceptable in every 10 years. In other words, it means those risks whose benefits are so great that individ‐ uals or groups in society are willing to take or be subjected to the risk. It is usually calculat‐ ed in actions taken to minimize the disaster risk. The probability of occurrence of an acceptable risk is small. The concept of acceptable risk evolved partly from the understand‐ ing that absolute safety is generally an unachievable goal and that even very low exposures to certain toxic substances may confer some level of risk.

Risk management is considered as the complete process of risk assessment and risk reduc‐ tion. Risk reduction implies some methods and measures, such as legislative, organizing, economic, engineering, information, and others. Sometimes, in a narrow sense, risk manage‐ ment is considered as measures for risk reduction. And, in this sense, the problem of risk management is seen as a series of events leading to risk reduction and avoiding. It includes modeling, monitoring, forecasting, prognosis, engineering works, insurance, and others.

Summarizing the systematic approaches to research on hazards and disasters based on the risk concept, it is possible to present the next steps and scheme to establish criteria for rank‐ ing risk posed by different types of natural or man-made hazards and disasters:

	- a) legislative;
	- b) organizational and administrative;
	- c) economic, including insurance;
	- d) engineering and technical;
	- e) modeling;
	- f) monitoring;
	- g) information.

It is the responsibility of the local governments to establish rules meant to reduce the effects of environmental hazards and disasters. Land-use regulations and policies are required in areas that are prone to natural hazards. The absence of such regulations and destructive hu‐ man activities is among the main factors that favor environmental risk.

Vulnerability is the degree of loss of a given element or a set of elements exposed to the occurrence of a natural or man-made hazard. It is expressed on a scale of 0 (no loss) to 1

Risk assessment is considered as the process of making a recommendation on whether exist‐ ing risks are acceptable and present risk control measures are adequate, and if they are not, whether alternative risk control measures are justified or will be implemented. Risk assess‐

Sometimes, risk assessment is considered as risk calculation on the base of selected parame‐

Acceptable risk refers to the level of human and property loss that can be tolerated by an individual, household, group, organization, community, region, state, or nation. For in‐ stance, the risk of flooding can be accepted once every 500 years, but it is not acceptable in every 10 years. In other words, it means those risks whose benefits are so great that individ‐ uals or groups in society are willing to take or be subjected to the risk. It is usually calculat‐ ed in actions taken to minimize the disaster risk. The probability of occurrence of an acceptable risk is small. The concept of acceptable risk evolved partly from the understand‐ ing that absolute safety is generally an unachievable goal and that even very low exposures

Risk management is considered as the complete process of risk assessment and risk reduc‐ tion. Risk reduction implies some methods and measures, such as legislative, organizing, economic, engineering, information, and others. Sometimes, in a narrow sense, risk manage‐ ment is considered as measures for risk reduction. And, in this sense, the problem of risk management is seen as a series of events leading to risk reduction and avoiding. It includes modeling, monitoring, forecasting, prognosis, engineering works, insurance, and others.

Summarizing the systematic approaches to research on hazards and disasters based on the risk concept, it is possible to present the next steps and scheme to establish criteria for rank‐

ing risk posed by different types of natural or man-made hazards and disasters:

ment incorporates the risk analysis and risk evaluation phases.

to certain toxic substances may confer some level of risk.

1. Hazard identification; 2. Vulnerability evaluation;

4. Concept of acceptable risk;

7. Measures for risk reduction:

b) organizational and administrative; c) economic, including insurance; d) engineering and technical;

3. Risk analysis;

5. Risk assessment; 6. Risk mapping;

a) legislative;

e) modeling; f) monitoring; g) information.

ters and establishment of ranking risk criteria.

(total loss).

X Preface

For example, whenever a landslide occurs, no matter if it is caused by slope saturation with water, seismic activity, or a volcanic eruption, the damages are disastrous. Thousands of households may be swept away or buried in mud and tens to hundreds of people could lose their lives.

This apocalyptic image should make local governments pay more attention to the preven‐ tion of such natural phenomena. It is important for a local government to know which areas are prone to landslides and take appropriate measures in order to reduce vulnerability to such hazards.

Vulnerability to landslides depends on location, frequency of landslide events, type of hu‐ man activity in the area, and other factors.

The effects on people and buildings can be lessened if hazardous areas are avoided or if activities in such areas are restricted or deployed under certain conditions. Local govern‐ ments are responsible for land-use policies and other regulations meant to reduce the risks for landslides to take place.

Exposure to hazards may be reduced if individuals educate themselves on the past history of these phenomena. Departments of local governments that are responsible with planning and engineering may help a lot with their advice.

People can also benefit from the professional services of engineering geologists, civil engi‐ neers, or geotechnical engineers, all qualified to evaluate the potential of a hazardous site.

Due to the huge losses that landslides imply, their prevention is of maximum importance for all the people living in the area of hazard. Preventing a landslide from causing material damage and human losses should be a main goal of local authorities.

Similar situation occurs in any kind of human activity and life.

The book reflects the state-of-the-art problem and addresses the risk assessment to establish the criteria for ranking risk posed by different types of natural or man-made hazards and disasters, medical and health problems, financial crisis, and environmental catastrophes; to quantify the impact that hazardous event or process has on person, population, environ‐ ment, and structures; and to enhance the strategies for risk reduction and avoiding.

**Dr. Valentina Svalova**

Sergeev Institute of Environmental Geoscience Russian Academy of Sciences Moscow, Russia

## **Natural Risk Assessment**

Provisional chapter

### **Landslides: Methodology to Select Stabilizing Construction Works** Landslides: Methodology to Select Stabilizing

DOI: 10.5772/intechopen.70797

Oscar Andrés Cuanalo Campos

Construction Works

Additional information is available at the end of the chapter Oscar Andrés Cuanalo Campos

http://dx.doi.org/10.5772/intechopen.70797 Additional information is available at the end of the chapter

#### Abstract

In landslide areas, after assessing the risk level, the obligatory questions from government authorities, communities, civil protection managers, and researchers are: What can we do? What should we do? What must we do? There are different strategies to reduce the vulnerability and risk: (a) increasing the knowledge of the population, (b) establishing an early warning system, and (c) selecting and constructing structures. The aim of this chapter is to present the methodology to select stabilizing construction works to avoid a landslide, through the "valuation factors," which are parameters to assess the intrinsic and trigger instability factors (morphology, geology, hydrogeology, vegetation, rainfall, earthquake, erosion, human activity, etc.). The valuation factors are presented in graphs, equations, and tables; based upon them, the different construction works are selected, including (a) geometric adjusting for reducing destabilizing forces; (b) reinforcement elements, anchors, and pile barriers to increase the resistive forces; (c) drainage for eliminating surface runoff water or lowering the hydrostatic pressure; (d) retaining walls to support the horizontal pressure; and (e) surface protection to prevent rock falls and reduce erosion and infiltration. The methodology has been used successfully in several mountainous regions: Puebla, Hidalgo, Chiapas, Baja California in México, and Ocaña in Colombia.

Keywords: landslides, construction works, valuation factors

### 1. Introduction

The landslides often cause disasters and damage to people and their properties at the mountainous areas around the world; these disasters cause casualties and economic losses, such as housing, infrastructure, public services, roads, bridges, hospitals, etc., and the interruption of the normal activities of the region, such as agriculture, livestock, commerce,

© 2018 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.

tourism, financial transactions, etc. A fundamental problem to solve is to make the investments for reconstructing and rehabilitating the destroyed places, which must be obtained from other social investment programs, donations from other countries, and/or sources of external financing that lead to indebtedness and impoverishment of communities, regions, or countries [1].

The first step to establish adequate strategies for prevention, reduction, management, and risk mitigation is to assess landslide hazard, vulnerability, and risk, the latter in terms of casualties and economic losses. The rational solution to landslide problem is to relocate exposed and vulnerable people to secure sites, but acquiring land in mountainous regions is very difficult; besides the majority of population is rooted to its origin place, and it cannot be relocated so easily.

### 1.1. The landslide problem

Landslide is a failure through a surface in which shear resistance has been exceeded; it is featured by the movement of slope materials that slide downhill.

Landslides can occur due to natural and human factors (intrinsic and trigger factors); although many landslides are triggered by natural phenomena (heavy rains, earthquakes, volcanism, freezing and thawing, erosion and scouring, etc.), it can be estimated that many of those that have caused deaths and injuries can be attributed to human activity impact.

The landslide material may include from a simple rock that falls to a great slide of several hundreds or thousands of cubic meters of material dragged in an avalanche or in a debris flow. They also range in extent some affect only a very small area while others entire regions. The distance that the material travels during movement can also differ significantly, with displacements ranging from a few cm to many km in length, depending on the volume of material, its water content, and the slope inclination. The velocity of a landslide may range from a slow, almost undetectable, gradual movement that remains active for a long period of time (displacements of a few cm per year), to sudden rapid collapse.

#### 1.2. The landslide disasters

Landslides are increasingly affecting our planet, like earthquakes, volcanic eruptions, hurricanes, floods, avalanches, etc., amplifying their intensity by different human activities that modify the delicate balance in nature.

In some mountainous regions at Central and South America, there are many communities belonging to ethnic groups that inhabit areas classified as high and very high poverty, whose features, among others, include localities of less than 2500 inhabitants, illiterate population in a large percentage, very low income, precarious social infrastructure, and houses built with fragile materials such as plastic, cardboard, and/or wood. In other places, there also are displaced populations due to social conflict, forcing them to move and take refuge in very vulnerable areas. In all these places, usually natural phenomena cause real disasters to impact on highly vulnerable communities [2].

### 2. Landslide instability factors

Landslide instability factors can be divided into two large groups—intrinsic and triggers—the first ones depend on the internal properties of slopes material and have a close relation with the type of failure and the susceptibility of the slope to a specific movement. The second ones, known also as external factors, are directly influenced by the climatic conditions, by extreme events such as earthquakes and volcanism, and the impact by human activities [3, 4].

### 3. Risk analysis

In order to assess the risk, a detailed analysis of the landslide hazard and the vulnerability of exposed people is required. Figure 1 shows a sequential scheme that summarizes the different steps to be taken into account; a brief description is given below [5].

#### 3.1. Hazard

tourism, financial transactions, etc. A fundamental problem to solve is to make the investments for reconstructing and rehabilitating the destroyed places, which must be obtained from other social investment programs, donations from other countries, and/or sources of external financing that lead to indebtedness and impoverishment of communities, regions,

The first step to establish adequate strategies for prevention, reduction, management, and risk mitigation is to assess landslide hazard, vulnerability, and risk, the latter in terms of casualties and economic losses. The rational solution to landslide problem is to relocate exposed and vulnerable people to secure sites, but acquiring land in mountainous regions is very difficult; besides the majority of population is rooted to its origin place, and it cannot be relocated so

Landslide is a failure through a surface in which shear resistance has been exceeded; it is

Landslides can occur due to natural and human factors (intrinsic and trigger factors); although many landslides are triggered by natural phenomena (heavy rains, earthquakes, volcanism, freezing and thawing, erosion and scouring, etc.), it can be estimated that many of those that

The landslide material may include from a simple rock that falls to a great slide of several hundreds or thousands of cubic meters of material dragged in an avalanche or in a debris flow. They also range in extent some affect only a very small area while others entire regions. The distance that the material travels during movement can also differ significantly, with displacements ranging from a few cm to many km in length, depending on the volume of material, its water content, and the slope inclination. The velocity of a landslide may range from a slow, almost undetectable, gradual movement that remains active for a long period of time (dis-

Landslides are increasingly affecting our planet, like earthquakes, volcanic eruptions, hurricanes, floods, avalanches, etc., amplifying their intensity by different human activities that

In some mountainous regions at Central and South America, there are many communities belonging to ethnic groups that inhabit areas classified as high and very high poverty, whose features, among others, include localities of less than 2500 inhabitants, illiterate population in a large percentage, very low income, precarious social infrastructure, and houses built with fragile materials such as plastic, cardboard, and/or wood. In other places, there also are displaced populations due to social conflict, forcing them to move and take refuge in very vulnerable areas. In all these places, usually natural phenomena cause real disasters to impact

featured by the movement of slope materials that slide downhill.

placements of a few cm per year), to sudden rapid collapse.

have caused deaths and injuries can be attributed to human activity impact.

or countries [1].

4 Risk Assessment

1.1. The landslide problem

1.2. The landslide disasters

modify the delicate balance in nature.

on highly vulnerable communities [2].

easily.

Historical records of landslides in the study area, including their geographical location, magnitude, intensity, degree of affectation or damage, and their frequency, must be investigated. From these data, a catalog or inventory of landslides that includes the type of movement and the intrinsic and trigger factors of the instability is elaborated [6].

#### 3.2. Vulnerability

The authors of this chapter propose to evaluate the population vulnerability from the exposure level (EL) and the expected damage degree (EDD): the first value according to the height of the slope and the safety factor obtained from the geotechnical stability analysis and the second based on the type of structures constructed (degree of fragility) and velocity of landslide [7, 8].

#### 3.3. Risk

The risk assessment should result in the number of people affected and the cost of damages caused by the occurrence of the phenomenon under study [9].

### 4. Slope stability analysis

The landslides and slope instability are among the most common failure of earth masses or rocks. The weight of the land mass and their water content is the main force that produces the failure, while the shear strength of the terrain, diminished by the water pressure, is the main strength. Analysis of the slope stability is a problem of plastic equilibrium; when the mass is about to fail, the forces that produce the movement have become equal to the resistance that opposes the mass to be moved. A slight increase in forces is sufficient to produce a continuous deformation that can end in the general failure.

Figure 1. Sequential scheme to assess landslide hazard, vulnerability, and risk [5].

#### 4.1. Quantitative stability assessment

The classical quantitative analysis of slope stability gives the safety factor and the location and geometry of the failure surface, using the parameters related to the intrinsic characteristics of the hill that depend mainly on its origin and geological formation, including topography, geology, soil mechanics, and groundwater.

#### 4.1.1. Limit equilibrium methods

They rely exclusively on the laws of static to determine the state of equilibrium of a potentially unstable slope. They do not take into account the deformations of the land and assume that the shear strength is fully and simultaneously mobilized along the failure surface. The most commonly used limit equilibrium methods by computer programs are the following: Fellenius, Bishop, Janbu, Bell, Sarma, Spencer, and Morgenstern and Price [10].

#### 4.1.2. Failure surface

The failure surface is the interface zones between the potentially unstable or moving ground or rock mass and the stable or static ground mass of the slope. These surfaces have very variable geometric shapes, but in the particular case of landslides, two main groups can be considered: the curvilinear and concave surfaces characteristic of the rotational landslides and flat or undulating surfaces, typical of translational landslides.

#### 4.1.3. Safety factor

Vulnerability Map

Hazard Map

The safety factor (SF) is used to evaluate if a slope is stable under conditions at a given site. The acceptable value of safety factor is selected taking into account the consequences or damages that could cause the slide. In geotechnical slope stability, the values range from 1.2 to 1.5 or higher, depending on the confidence in the geotechnical data (exploration, soil sampling, and laboratory testing), as well as the available information on the intrinsic and trigger factors of instability. Overall the safety factor can be defined as the ratio of natural shear strength to destabilizing forces.

#### 4.2. Qualitative stability assessment

The calculation methods described in Section 4.1.1 allow us to take into account the influence of some of instability factors, and there are powerful calculation programs to stability analysis. In order to take into account most instability factors, a qualitative analysis is necessary through the valuation factors that will be described below.

#### 4.2.1. Valuation factors

Trade

Trade

Infrastructure

Environmental and natural resources

Economy & finance

Hazard H) Scale 0 - 1

6 Risk Assessment

Landslides

Vulnerability

(V) Scale 0 - 1

Cost

Scale . Lives Historical records

. Geographic location . Magnitude & intensity . Damage degree scale

Functional

Social

. \$ Economical assets

Figure 1. Sequential scheme to assess landslide hazard, vulnerability, and risk [5].

Lives

Physical

. Frequency

Exposure level

Risk Map

Risk Assessment (R)

Expected damage degree

Strategies

Measures

Organization

Population density

Landslides inventory

Heigh of slope

Geotechnical safety factor

Type of structures (degree of fragility)

Landslide velocity

Intrinsic factors

Trigger factors

The valuation factors are a set of parameters that allow to evaluate the influence of intrinsic and trigger factors (Table 1). The characteristics of each factor should be adequately analyzed to involve its effect on the behavior; one way of doing this is by assigning them a range of weighted values indicating their effect on the slope stability.

Table 1. Summary of valuation factors proposed by author.

The author proposes valuation factor values between 0 and 1 (arbitrarily selected but with common and logical sense); the first corresponds to a null or minimal effect on stability (not influenced or very little) and the second the one with the greatest impact on it (influences significantly). Non-extreme effects are evaluated with intermediate values [11].

#### <IP_ADDRESS>. Morphology and topography valuation factor (Fmt)

The "Fmt" takes into account the morphology and maximum inclination of the slope; its height, although importantly influences stability, is considered in the soil mechanics valuation factors described later. The gravitational effect of a unit weight of the ground (W = 1) is divided into two forces, normal and parallel components to slope inclination (β). The latter component represents the weight of soils or rocks that slide and whose value is proposed as a valuation factor (Eq. (1)):

$$Fmt = \operatorname{sen} \beta. \tag{1}$$

#### <IP_ADDRESS>. Geology valuation factor (Fg)

The rock geological structure defined by its folding and discontinuities is taken into account because it causes an anisotropic behavior that affects the type of failure and its magnitude. Another important aspect is the material weathering caused by the climatic conditions (temperature, humidity, rain, wind, solar radiation, etc.) that produce physical and chemical alterations of rocks and their minerals, causing a wide range of variation in the geotechnical properties that origin a mixed behavior between soil and rock.

The geology valuation factor (Fg) is presented in Tables 2 and 3 and Figures 2 and 3, in which values include (a) the fold inclination "α" determined from Eq. (2), (b) the fracture of the rock from the rock quality designation (RQD), (c) the chemical and physical weathering from the adequacy of data between weather and weathering processes proposed by Emblenton and Thurner [12], and (d) the physical and mechanical properties of the rock:

$$F \mathbf{g}\_{\text{flds}} = \text{sen}\,\alpha \tag{2}$$

The final valuation factor is obtained as an average of the aforementioned.

\* Adaptation of graphs between climate and the weathering processes proposed by Emblenton and Thurner [12]. RQD: rock quality designation.

Ds: rock properties from laboratory test (volumetric weight for physical properties and simple compression strength for mechanical properties).

De: reference value considering massive rock (Table 3).

Table 2. Geology valuation factor (Fg).

The author proposes valuation factor values between 0 and 1 (arbitrarily selected but with common and logical sense); the first corresponds to a null or minimal effect on stability (not influenced or very little) and the second the one with the greatest impact on it (influences

The "Fmt" takes into account the morphology and maximum inclination of the slope; its height, although importantly influences stability, is considered in the soil mechanics valuation factors described later. The gravitational effect of a unit weight of the ground (W = 1) is divided

significantly). Non-extreme effects are evaluated with intermediate values [11].

Valuation factor Concept Function of

Intrinsic features Morphology and topography Shape and inclination of slope

Trigger factors Rain Average annual precipitation

Geology\* Folding

Fracture Weather

Soil thickness

Basin area

Overloads Deforestation

Drainage grid features

Density of foliage Covered area Root type

Soil mechanics Coarse soils Slope inclination, friction angle "φ"

Hydrogeology\* Slope inclination, saturation degree

Vegetation\* Types of vegetation

Earthquake Seismic coefficient Volcanism Volcanic activity

Human activities\* Cuts and excavations

Safety factor Quantitative value

Erosion and scouring\* Superficial soil characteristics

Physical and mechanical properties

Fine soils Inclination of slope, height, volumetric weight, and undrained strength

<IP_ADDRESS>. Morphology and topography valuation factor (Fmt)

Table 1. Summary of valuation factors proposed by author.

Geotechnical slope stability Failure surface Depth

\*

Average value.

8 Risk Assessment

Table 3. Physical and mechanical properties of sound rocks.

#### <IP_ADDRESS>. Soil mechanics valuation factor (Fsm)

Soil mechanics valuation factors (Fsm) take into account the type of soil, coarse and fine, according to the Unified Soil Classification System. For coarse soils, their relative compactness defined by internal friction angle φ is the main factor governing their behavior, while for fine soils, the height, the slope inclination, the volumetric weight, and the cohesion as a function of water content are the factors that control their behavior.

#### <IP_ADDRESS>.1. Coarse soils

The stability of a slope formed by coarse soils depends fundamentally on its strength (internal friction angle "φ") and the slope inclination "β." The geotechnical safety factor "SF" is determined by the Eq. (3):

$$\text{SF} = \frac{\tan \phi}{\tan \beta} \tag{3}$$

Critical stability occurs when the slope angle (β) is equal to the internal friction angle (ϕ); in this case the safety factor SF = 1 and the slope will be in a critical equilibrium condition, so that the soil mechanics valuation factor "Fsm" will also be unitary. When the safety factor (SF) is equal to 1.5 (proposed value as the lower limit), the behavior will be stable, and then the valuation factor is equal to zero (Fsm = 0) (Table 4).

Figure 2. Geology valuation factor by chemical weathering (Fg).

<IP_ADDRESS>. Soil mechanics valuation factor (Fsm)

Table 3. Physical and mechanical properties of sound rocks.

<IP_ADDRESS>.1. Coarse soils

10 Risk Assessment

mined by the Eq. (3):

water content are the factors that control their behavior.

Rock origin Type Classification Volumetric weight (KN/m<sup>3</sup>

Igneous Extrusive volcanic Andesite 21.6–23.0 206–314

Sedimentary Detritical Quartzite 25.5–26.5 196–314

Metamorphic Massive Quartzite 25.5–26.5 196–314

Intrusive volcanic Diorite 26.5–27.9 177–240

Chemical Dolomite 24.5–25.5 88–245 Organic Limestone 22.5–25.5 78–137

Foliated Phyllite 24.5–26.5 98–177

Basalt 26.5–28.4 147–211 Rhyolite 23.5–25.5 – Tuff 18.6–22.5 10–45

Gabbro 29.4–30.4 206–275 Granite 25.5–26.5 167–226

Sandstone 22.5–25.5 54–137 Shale 21.6–25.5 29–69 Siltstone – – Conglomerate – –

Choral 22.5–25.5 78–137

Marble 25.5–27.5 118–196

Schist 24.5–27.5 49–59 Gneiss 26.5–29.4 157–196

Soil mechanics valuation factors (Fsm) take into account the type of soil, coarse and fine, according to the Unified Soil Classification System. For coarse soils, their relative compactness defined by internal friction angle φ is the main factor governing their behavior, while for fine soils, the height, the slope inclination, the volumetric weight, and the cohesion as a function of

The stability of a slope formed by coarse soils depends fundamentally on its strength (internal friction angle "φ") and the slope inclination "β." The geotechnical safety factor "SF" is deter-

SF <sup>¼</sup> tan <sup>φ</sup>

Critical stability occurs when the slope angle (β) is equal to the internal friction angle (ϕ); in this case the safety factor SF = 1 and the slope will be in a critical equilibrium condition, so that

tan <sup>β</sup> (3)

) Compression resistant (MN/m<sup>2</sup>

)

Figure 3. Geology valuation factor by physical weathering (Fg).

Table 4. Soil mechanics valuation factor for coarse soil (Fsm).

#### <IP_ADDRESS>.2. Cohesive and friction-cohesive soils

For a slope of cohesive or friction-cohesive soils, both of them homogeneous, the stability depends on its height, inclination, and resistant properties. All these variables are presented in a simple way in equations by the Taylor method for slope stability analysis (Eqs. (4) and (5)):

$$\text{SF} = \frac{Hc}{H} \tag{4}$$

$$\text{Hc} = \frac{\text{Ns}^\* \text{ } \text{C}}{\text{y}} \tag{5}$$

where SF = safety factor, Hc = critical height, H = slope height, Ns = stability number (as a function of internal friction angle "φ" and slope inclination "β") (Figure 4), C = soil cohesion, and γ = natural volumetric weight.

For a stratified soil profile, authors recommend to use only the properties of the poor quality stratum.

From the above equations, the soil mechanics valuation factors for cohesive and frictioncohesive soils were obtained taking into account the following:

• Therefore, safety factor values between 1 and 1.5 correspond to intermediate values between 1 and 0, respectively, for the valuation factor Fsm.

The soil mechanics valuation factor proposed for cohesive and friction-cohesive soils are presented in Figure 5.

Figure 4. Stability number "Ns."

<IP_ADDRESS>.2. Cohesive and friction-cohesive soils

Table 4. Soil mechanics valuation factor for coarse soil (Fsm).

SF: safety factor from Eq. (3).

12 Risk Assessment

and γ = natural volumetric weight.

represents a potential risk condition.

stratum.

For a slope of cohesive or friction-cohesive soils, both of them homogeneous, the stability depends on its height, inclination, and resistant properties. All these variables are presented in a simple way in equations by the Taylor method for slope stability analysis (Eqs. (4) and (5)):

Internal friction angle "φ" SF = 1.5 SF = 1.4 SF = 1.3 SF = 1.2 SF = 1.1 SF = 1

26o 18o 19.3o 26.7<sup>o</sup> 22.2o 24o 26o 28o 19.5<sup>o</sup> 20.8o 22.2<sup>o</sup> 23.9o 25.8o 28o 30o 21o 22.4o 23.9<sup>o</sup> 25.7o 27.7o 30o 36o 25.8<sup>o</sup> 27.4o 29.2<sup>o</sup> 31.2o 33.5o 36o 41o 30o 31.8o 33.8<sup>o</sup> 35.9o 38.3o 41o 46o 34.6<sup>o</sup> 36.5o 38.5<sup>o</sup> 40.8o 43.3o 46o

Slope inclination "β"

Fsm = 0 Fsm = 0.2 Fsm = 0.4 Fsm = 0.6 Fsm = 0.8 Fsm = 1

SF <sup>¼</sup> Hc

Hc <sup>¼</sup> Ns<sup>∗</sup> <sup>C</sup>

where SF = safety factor, Hc = critical height, H = slope height, Ns = stability number (as a function of internal friction angle "φ" and slope inclination "β") (Figure 4), C = soil cohesion,

For a stratified soil profile, authors recommend to use only the properties of the poor quality

From the above equations, the soil mechanics valuation factors for cohesive and friction-

• When SF = 1, there is a limit equilibrium, and therefore the height of the slope "H" is equal to the critical height "Hc." In this case, you will have a valuation factor Fsm = 1 which

• As the safety factor increases, stability improves and the Fsm decreases. When SF = 1.5, which is the minimum acceptable value, there will be a null valuation factor (Fsm = 0).

cohesive soils were obtained taking into account the following:

<sup>H</sup> (4)

<sup>γ</sup> (5)

Figure 5. Soil mechanics valuation factor for cohesive and friction-cohesive soils (Fms).

### <IP_ADDRESS>. Hydrogeological valuation factor (Fh)

The water content has a significant influence on slope stability due to [13] (a) reduction of shear strength of the ground by decreasing the effective tension, (b) increased pressure on traction cracks with corresponding increase of destabilizing forces, (c) increased volumetric weight by saturation, (d) internal erosion by underground flow, (e) weathering and changes in the mineralogical composition of the material, and (f) opening of discontinuities by frozen water.

The hydrogeological valuation factor proposed (Fh) is obtained as a function of the soil saturation degree (Gw), the slope angle (β), and the soil stratum thickness (e), as explained below.

### <IP_ADDRESS>.1. Soil saturation degree and slope angle

Figure 6 shows "Fh" as a function of saturation degree "Gw" and slope angle "β."

### <IP_ADDRESS>.2. Soil stratum thickness

Authors consider that when the soil thickness is small, it is anchored to the deepest strata by the trees roots. Conversely, for greater soil thicknesses, the sliding surface will be deeper, increasing the risk of failure. Table 5 gives "Fh" as a function of the soil stratum thickness "e."

#### <IP_ADDRESS>. Vegetation valuation factor (Fv)

There is evidence of the positive effect on vegetation on slope stability. The vegetation valuation factors (Fv) depend on the type of vegetation, the density of foliage which dampens the impact of raindrops, the covered vegetation area, and the depth of the roots that absorb subsoil

Figure 6. Hydrogeological valuation factor by saturation degree (Fh).

Table 5. Hydrogeology valuation factor for soil thickness (Fh).

<IP_ADDRESS>. Hydrogeological valuation factor (Fh)

14 Risk Assessment

<IP_ADDRESS>.1. Soil saturation degree and slope angle

<IP_ADDRESS>.2. Soil stratum thickness

<IP_ADDRESS>. Vegetation valuation factor (Fv)

0

10

20

30

40

50

Saturation degree Gw (%)

60

70

80

90

100

The water content has a significant influence on slope stability due to [13] (a) reduction of shear strength of the ground by decreasing the effective tension, (b) increased pressure on traction cracks with corresponding increase of destabilizing forces, (c) increased volumetric weight by saturation, (d) internal erosion by underground flow, (e) weathering and changes in the mineralogical composition of the material, and (f) opening of discontinuities by frozen water. The hydrogeological valuation factor proposed (Fh) is obtained as a function of the soil saturation degree (Gw), the slope angle (β), and the soil stratum thickness (e), as explained below.

Figure 6 shows "Fh" as a function of saturation degree "Gw" and slope angle "β."

Authors consider that when the soil thickness is small, it is anchored to the deepest strata by the trees roots. Conversely, for greater soil thicknesses, the sliding surface will be deeper, increasing the risk of failure. Table 5 gives "Fh" as a function of the soil stratum thickness "e."

There is evidence of the positive effect on vegetation on slope stability. The vegetation valuation factors (Fv) depend on the type of vegetation, the density of foliage which dampens the impact of raindrops, the covered vegetation area, and the depth of the roots that absorb subsoil

0.75

1.0

0 10 20 30 40 50 60 70 80 90

0.50

0.25

0.125

0.065

Figure 6. Hydrogeological valuation factor by saturation degree (Fh).

Slope angle (o)

\* The density of foliage is evaluated as the percentage of sun that passes through the leaves in the area that projects the tree in summer.

Table 6. Vegetation valuation factor (Fv).

water and anchorage the superficial soil to the rock; all of them were obtained from a linear interpolation considering zero value for minimum effect on stability and one for significant effect (Table 6). The final valuation factor is obtained as an average of the aforementioned.

#### <IP_ADDRESS>. Rainfall valuation factor (Fr)

Rain is one of the main factors affecting the slope stability; many landslides occur during or after rainy periods, and areas with higher annual rainfall present more stability problems, due to the groundwater with higher flow and more weathered materials. The shallow landslides due to torrential rainfall depend on the combined effect of infiltration and loss of apparent cohesion, which are influenced by the amount of rainfall and the duration of the storm [14]. Rainfall valuation factors (Fr) are determined by linear interpolation from the average annual rainfall data (Table 7).

#### <IP_ADDRESS>. Earthquake valuation factor (Fe)

Earthquakes are trigger agents that cause deformations and cracks on slopes. Seismic shaking can lead to landslides, flows, and avalanches depending on the intrinsic characteristics of the

Table 7. Rainfall valuation factor (Fr).

ground and the magnitude and distance to the epicenter [15]. The earthquake valuation factors (Fe) are determined from a linear correlation with the seismic design coefficients (Cs); these latter are obtained from municipal building codes as a function of the terrain type (hard, medium, or soft), the frequency which the event occurs, and the ground acceleration, the latter depending on the magnitude and intensity of the movement (Table 8).

#### <IP_ADDRESS>. Erosion and scouring valuation factor (Fes)

The erosion and scouring valuation factor (Fes) is obtained from the basin geometric characteristics (length and width), because the basin shape influences the stream hydrograph and the flow rate. The characteristics of the drainage density (Dd = sum of the tributary flows length between the total basin area) were also taken into account, considering that the higher drainage density will have higher flows in the stream [16]. Finally, the characteristics of the ground evaluated according to their infiltration capacity "If" are included. Eqs. (6)–(8) present the "Fes" as a function of the aforementioned:

Zone A: very low seismicity; no earthquake in the last 80 years, ground acceleration <10% gravity acceleration. Zone B: low seismicity; earthquakes not so frequents, ground acceleration <70% gravity acceleration. Zone C: medium seismicity; earthquakes not so frequents, ground acceleration <70% gravity acceleration. Zone D: high seismicity; very frequent earthquakes, ground acceleration >70% gravity acceleration.

Table 8. Earthquake valuation factor (Fe).

$$Fes\_{\text{basis\\_charactersics}} = 0.0625^\* \left(\frac{L}{W}\right) \tag{6}$$

$$F \text{es}\_{druinage\ density} = 0.1^\* \, Dd\tag{7}$$

$$Fes\_{inflration} = 1 - 0.033^\* \, lf \tag{8}$$

where L = basin length (km), W = basin width (km), Dd = drainage density (km/km<sup>2</sup> ), and If = infiltration rate (mm/h).

#### <IP_ADDRESS>. Human activity valuation factor (Fha)

ground and the magnitude and distance to the epicenter [15]. The earthquake valuation factors (Fe) are determined from a linear correlation with the seismic design coefficients (Cs); these latter are obtained from municipal building codes as a function of the terrain type (hard, medium, or soft), the frequency which the event occurs, and the ground acceleration, the latter

Average annual rainfall <400 mm 400–800 mm 800–1500 mm 1500–3000 mm 3000–4500 mm Classification Very low Low Medium High Very high Valuation factor (Fr) <0.09 0.09–0.18 0.18–0.33 0.33–0.67 0.67–1

The erosion and scouring valuation factor (Fes) is obtained from the basin geometric characteristics (length and width), because the basin shape influences the stream hydrograph and the flow rate. The characteristics of the drainage density (Dd = sum of the tributary flows length between the total basin area) were also taken into account, considering that the higher drainage density will have higher flows in the stream [16]. Finally, the characteristics of the ground evaluated according to their infiltration capacity "If" are included. Eqs. (6)–(8) present the

Seismic zone Soil type Seismic coefficient (Cs) Valuation factor Fe

Medium 0.16 0.19 Soft 0.2 0.23

Medium 0.3 0.35 Soft 0.36 0.42

Medium 0.64 0.74 Soft 0.64 0.74

Medium 0.86 1 Soft 0.86 1

Zone A: very low seismicity; no earthquake in the last 80 years, ground acceleration <10% gravity acceleration. Zone B: low seismicity; earthquakes not so frequents, ground acceleration <70% gravity acceleration. Zone C: medium seismicity; earthquakes not so frequents, ground acceleration <70% gravity acceleration. Zone D: high seismicity; very frequent earthquakes, ground acceleration >70% gravity acceleration.

A Hard 0.08 0.09

B Hard 0.14 0.16

C Hard 0.36 0.42

D Hard 0.5 0.58

depending on the magnitude and intensity of the movement (Table 8).

<IP_ADDRESS>. Erosion and scouring valuation factor (Fes)

Characteristics Rainfall valuation factor (Fr)

Table 7. Rainfall valuation factor (Fr).

16 Risk Assessment

"Fes" as a function of the aforementioned:

Table 8. Earthquake valuation factor (Fe).

The relationship between landslides and velocity of urbanization on slopes has been demonstrated; the worst cases have been registered in geotechnical susceptible areas with rapid and disordered urban development. Since human actions directly influence nature, this human activity valuation factor (Fha) is assessed by taking into account cuts or excavations, landfills, building overloads, and deforestation (Table 9).

The human activity valuation factor by overloads was obtained from the average loads or stresses transmitted by the building to the soil foundation and the population density, which both directly impact on the behavior and slope stability (Figure 7).

The final valuation factor is obtained as an average of the aforementioned.

#### <IP_ADDRESS>. Geotechnical slope stability valuation factor (Fgss)

The results of geotechnical slope stability analysis are the safety factor (SF) and the location of failure surface; these data are important to know a potential failure; furthermore we suggest taking them into account to obtain geotechnical slope stability factor (Fgss), as a function of the depth of failure surface (superficial, shallow, deep, and very deep) and the value of the safety factor (Table 10).

W = overload.

Table 9. Human activity valuation factor (Fha).

Figure 7. Human activity evaluation factor by overloads (Fha).

Table 10. Geotechnical slope stability valuation factor (Fgss).

### 5. Methodology to select stabilizing construction works

Most techniques and construction works to stabilize unstable slopes or active landslides can be included in the following classification groups: (a) geometric adjusting, (b) drainage, (c) reinforcing structural elements, (d) retaining walls, (e) surface protection, and (f) soil improvement.

The most effective and economical solution is a combination of two or more stabilization techniques [17]. At first glance it could be thought that the quantitative evaluation of stability by geotechnical analysis of equilibrium-limited methods (safety factor and the failure surface) is sufficient to propose and decide the types of construction works to be used. However, it must be taken in mind that many factors influencing stability and construction stabilization works are difficult to model and include in the analysis using the calculation methods and should be evaluated in a qualitative way.

### 5.1. Methodology description

The methodology uses both quantitative and qualitative analyses, organized in stages as described below:

#### 5.1.1. Data collection from engineering: geological studies

In this stage, the following data are obtained: topography (height and slope inclination), geology (folding, fracturing, and weathering of rocks), soil mechanics (classification and physical-mechanical properties of soils and rocks, thickness of the soil strata, and saturation degree), seismology (classification and seismic coefficient according to local building codes), climatology (annual temperature and average annual rainfall), hydrology (drainage grid and its basin), studies of human activity impact (cuts or excavations, population density, overloads, type of constructions, number of floors of houses, and degree of deforestation), vegetation characteristics (type, foliage density, area covered, and depth of root), and volcanic activity.

### 5.1.2. Stability analysis before the construction of stabilization works

#### <IP_ADDRESS>. Quantitative analysis: safety factor (SF) and critical failure surface

Slope modeling and geotechnical stability analysis using some of the limit equilibrium methods: Fellenius, Bishop, Janbu, Bell, Sarma, Spencer, or Morgenstern and Price.

### <IP_ADDRESS>. Qualitative analysis: valuation factors

5. Methodology to select stabilizing construction works

Slope stability analysis Geotechnical slope stability valuation factor (Fgss)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Very low

Figure 7. Human activity evaluation factor by overloads (Fha).

Table 10. Geotechnical slope stability valuation factor (Fgss).

Medium

Low

Human activity valuation factor (Fha)

18 Risk Assessment

Most techniques and construction works to stabilize unstable slopes or active landslides can be included in the following classification groups: (a) geometric adjusting, (b) drainage, (c) reinforcing

0 100 200 300 400 500 600 700

W = 10 kN/m2

W = 20 kN/m<sup>2</sup>

W = 30 kN/m2

W = 40 kN/m<sup>2</sup>

Very

high

Population density (people/km2)

Failure surface Superficial Shallow Deep Very deep

Safety factor (SF) Unstable Critical stability Stable

<1.5 m 1.5–5 m 5–12.5 m 12.5–20 m

0.25 0.50 0.75 1

<1 1–1.5 >1.5 1 0.75 0

High

The most effective and economical solution is a combination of two or more stabilization techniques [17]. At first glance it could be thought that the quantitative evaluation of stability by geotechnical analysis of equilibrium-limited methods (safety factor and the failure surface) is sufficient to propose and decide the types of construction works to be used. However, it must be taken in mind that many factors influencing stability and construction stabilization

structural elements, (d) retaining walls, (e) surface protection, and (f) soil improvement.

If the safety factor (SF) obtained from geotechnical stability is lower than the minimum value required as an acceptable limit, it is necessary to use construction works to improve stability. The selection of these stabilizing construction works is made into qualitative way, through the valuation factors that consider the influence of intrinsic and trigger factors.

Once the valuation factors are obtained, it is necessary to establish the influence intervals to assess the level of care required as follows: (a) if valuation factor is <0.5, there will be no stability problems; (b) if the value is between 0.5 and 0.75, it requires attention; and (c) if the value is >0.75, it requires urgent solution.

#### 5.1.3. Selection of construction works and stabilization proposals

In landslide problems, it is common to combine several factors that give rise to a critical behavior, so it is very likely that a combination of construction works is also required to address the problem and avoid a risk condition. Table 11 summarizes the type of problem to be solved, the suitable construction work, and the aims of them.

Table 11. Instability factors and suitable construction works.

#### 5.1.4. Checking over slope stability with the proposed construction works

The selected construction works should ensure that safety factor (SF) is equal to or greater than the required minimum factor, so it is necessary to check that condition, including the works selected in the quantitative stability analysis, which is performed with the same methods that are used to assess geotechnical stability in a quantitative way, but now including these construction works (or their influence) in the modeling stage.

### 6. Results

The equations, figures, and tables of valuation factors presented in this chapter to evaluate the influence of the intrinsic and trigger factors, as data previously needed to select the construction structures to avoid landslides, are important tools to help different specialists who face the phenomenon. In addition to the above, the following is also required:

#### 6.1. Technical and economic assessment of stabilization proposals

Set up the necessary activities to carry out the stabilizing construction works: resources and their yields [18]. This is essential for the economic assessment of stabilization proposals where it is also important to include the direct costs of materials, labor, and equipment and indirect costs resulting from the expenses technical-administrative necessary for the correct execution of any construction work [19].

#### 6.2. Selection of the stabilizing construction proposal

As shown in Table 11, it is very common that the most effective and even economic stabilization method corresponds to the simultaneous application of two or more stabilization construction works, and sometimes, in addition to the cost factor, esthetic and environmental factors have to be taken into account. It should be noted that the final decision on the construction works to a potentially unstable slope or an active landslide must be in the hands of experienced specialists with broad knowledge of the intrinsic properties of the slope and the specific conditions of the region where it is located.

### Nomenclature

5.1.4. Checking over slope stability with the proposed construction works

Problem type Applicable construction works Specific objectives Morphologic Geometric adjustment Decreasing acting forces Geological Reinforcement, wire mesh Increasing resisting forces

Hydrological Drainage and surface protection Reducing soil saturation and weathering

Rain Drainage Decreasing pore pressure, avoid saturation and

Earthquake Reinforcement and retaining walls Increasing resistance and retaining potentially

Erosion Drainage, retaining walls and surface protection Avoid erosion and protect the hillside foot

Vulcanism Geometric adjustment and retaining walls Remove unstable materials and contain soil masses

Vegetation Surface protection Avoid erosion and reinforce soil

Soil mechanics Drainage, reinforcement, and superficial

Human activity Reinforcement, retaining walls, and surface

Failure surface Geometric adjustment, reinforcement, and retaining walls

Safety factor Geometric adjustment, reinforcement, and retaining walls

Table 11. Instability factors and suitable construction works.

protection

protection

20 Risk Assessment

phenomenon. In addition to the above, the following is also required:

6.1. Technical and economic assessment of stabilization proposals

struction works (or their influence) in the modeling stage.

6. Results

of any construction work [19].

The selected construction works should ensure that safety factor (SF) is equal to or greater than the required minimum factor, so it is necessary to check that condition, including the works selected in the quantitative stability analysis, which is performed with the same methods that are used to assess geotechnical stability in a quantitative way, but now including these con-

Decreasing pore pressure, increase resistance, and

Increasing resistance, contain potentially unstable

prevent erosion

unstable material

material, and reforest

Changing location

Increasing the value

erosion

The equations, figures, and tables of valuation factors presented in this chapter to evaluate the influence of the intrinsic and trigger factors, as data previously needed to select the construction structures to avoid landslides, are important tools to help different specialists who face the

Set up the necessary activities to carry out the stabilizing construction works: resources and their yields [18]. This is essential for the economic assessment of stabilization proposals where it is also important to include the direct costs of materials, labor, and equipment and indirect costs resulting from the expenses technical-administrative necessary for the correct execution

#### Author details

Oscar Andrés Cuanalo Campos

Address all correspondence to<EMAIL_ADDRESS>
Benemerita Autonomous University of Puebla, México

#### References

[7] Cuanalo O, Gallardo R. Fenómenos de Remoción en Masa. Acciones para Reducir la Vulnerabilidad y el Riesgo.162016. p. 30-38, http://vector.ucaldas.edu.co/downloads/Vector11\_5.pdf

H slope height

22 Risk Assessment

L basin length

W basin width SF safety factor

Author details

References

If infiltration rate

Ns stability number

RQD rock quality designation

Oscar Andrés Cuanalo Campos

[Accessed: 2017-07-07]

Belgium. pp 09-13

Address all correspondence to<EMAIL_ADDRESS>
[1] Benson Ch, Clay E. Understanding the Economic and Financial Impacts of Natural Disasters [Internet]. 2004. Available from: https://openknowledge.worldbank.org/bitstream/ handle/10986/15025/284060PAPER0Disaster0Risk0no.04.pdf?sequence=1&isAllowed=y

[2] Bitran D. Características del impacto socioeconómico de los principales desastres ocurridos en México en el periodo 1980–99 [Internet]. 2001. Available from: http://www.cenapred. unam.mx/es/DocumentosPublicos/PDF/SerieImpacto/Impacto1.pdf [Accessed: 2017-07-07] [3] Cuanalo O, Quezada P, Aguilar A, Olivan A, Barona E. Sismos y lluvias, factores detonantes de deslizamientos de laderas en las regiones montañosas de Puebla, México [Internet]. 2006. Available from: http://www.redalyc.org/pdf/730/73000413.pdf [Accessed: 8 July 2017] [4] Cuanalo O, Oliva A. Inestabilidad de la laderas. Factores desencadenantes de deslizam-

[5] Cuanalo O, Bernal E, Polanco G. Geotechnical stability analysis, fragility of structures and velocity of movement to assess landslides vulnerability. Natural Hazards and Earth

[6] Glade T. Quantitative landslide risk analysis: Between local field monitoring and spatial modeling. In: XIth International Mathematical Geology Congress; 3–8 September 2006;

System Sciences Discussions. 2014;2:5689-5720. DOI: 10.5194/nhessd-2-5689-2014

ientos. Editorial Académica Española, Germany. 2011; 156 p

Benemerita Autonomous University of Puebla, México

### **Chapter 2**

**Provisional chapter**

### **Natural Risk Management to Protect Critical Infrastructures: A Model for Active Learning Infrastructures: A Model for Active Learning**

**Natural Risk Management to Protect Critical**

DOI: 10.5772/intechopen.70606

Catalin Cioaca, Vasile Prisacariu and Mircea Boscoianu Mircea Boscoianu Additional information is available at the end of the chapter

Catalin Cioaca, Vasile Prisacariu and

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70606

#### **Abstract**

This scientific approach has been initiated in the context of the rapid and unpredictable developments of climatic factors that generate a major challenge for military critical infrastructure protection systems. The proposed methodology integrates on a specially designed decision-making platform the two approaches specific to risk management: adaptive-preventive (risk assessments at the local area based on the connection between climate change vectors–the asset of infrastructure–the potential impact on medium and long term) and adaptive-reactive (real-time event monitoring using emerging technologies: integration of sensors on a robotic aerial platform). The architecture of the research model was designed to meet both user requirements (modular, flexible, scalable) and the needs to overlap the stages of the risk management process. Model testing on simulated scenarios under laboratory conditions demonstrated the functionality and highlighted the expected performance.

**Keywords:** risk management methodology, climate vector, military critical infrastructure, aerial monitoring, decision support platform

### **1. Introduction**

Regarding regulatory framework, the *National Strategy on Critical Infrastructure Protection*, developed in 2011, is the framework document for the adoption and implementation of specific measures and actions to reduce the negative impacts of specific risk factors on critical infrastructure at a national and regional level [1]. The strategy has been completed in order to identify national critical infrastructures [2]. In order to achieve the directions of action proposed in the strategy, the following coordinates are considered: prevention, mitigation,

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons

and limitation of effects; response/intervention efficiency; and sustainability (risk analysis, correlation of resources with needs).

*Romania's National Climate Change Strategy 2013*–*2020* addresses the issue of natural risks in two distinct areas: the process of reducing greenhouse gas emissions in order to achieve the assumed national targets and the adaptation to the effects of climate change. The Ministry of Environment and Climate Change is monitoring the process of adaptation to the effects of climate change. There is no defense sector among the 13 sectors vulnerable to the negative impacts of climate change [3].

*The unitary risk assessment methodology and the integration of the sectorial risk assessments* aim to provide a common framework for analysis for the sectorial risk assessments. It provides information on the types of risks present on the territory of Romania. The methodology defines the stages for the identification of scenarios, the construction of risk scenarios as well as the criteria for their prioritization and selection in order to establish the representative scenarios to be subjected to the evaluation process [4].

At a community level, the European Commission has initiated starting with 2010 a process of creating a unitary methodological framework for risk assessment to improve the capacity of member states to respond by means of prevention, preparedness, and intervention measures to identified risks. This approach also aims to better manage and distribute resources for the effective and efficient management of disastrous events in the European Union (EU).

The guidelines formulated at the level of the European Commission are mainly [5]:

These directions are embodied in the security plans in the form of structured procedures on the following stages: identification of important elements; performing a risk analysis based on major threat scenarios, on vulnerabilities and potential impact; and identifying, selecting, and implementing technical and organizational solutions. Critical military infrastructures can be assessed against the level of preparedness to the threats posed by climate change based on the following indicators:

Climate assessment at national and international levels indicates that the impact of weather on human activities is inevitable and growing. Climate change related to extreme weather events will increase infrastructure damage in the future [6]. However, the normative and procedural framework for assessing climate risks on critical infrastructures in general and military in particular is not developed in a way that will effectively address this particularly complex issue.

To build the database regarding extreme natural events in Romania, we have used the International Disaster Database, a product of the Disaster Epidemiology Research Centre (CRED). Thus, during the period 1915–2015, 90 natural events with disastrous consequences were identified: drought (2); earthquake (10); epidemic (3); extreme temperatures (19); floods (49); landslides (1); and storms (6).

The most significant of these (according to the number of victims) are shown in **Table 1**.

For the period 2000–2015, Romania recorded 55 extreme natural events, the consequences of which sums 697 deaths and over 3 billion USD of material damage.

At European level, the temperature has risen by almost 1°C in the last century, faster than the global average. Rainfall has grown considerably in Northern Europe, whereas in the southern continent, droughts have become increasingly frequent. Recent extreme temperatures, such as the 2003 summer heat wave in Central and Western Europe and the summer of 2007 in Southeast Europe, which have exceeded any record, are a direct consequence of human climate change. Although single meteorological phenomena cannot be attributed to a single cause, statistical analysis has shown that the risk of such phenomena has already increased considerably due to climate change [7].

The forecasting of changes in the climate regime at a national level was performed for the period 2001–2030 (compared to the period 1961–1990) for the parameters: air temperature and precipitation level [7].

**Table 1.** Top 10 extreme natural events.

and limitation of effects; response/intervention efficiency; and sustainability (risk analysis,

*Romania's National Climate Change Strategy 2013*–*2020* addresses the issue of natural risks in two distinct areas: the process of reducing greenhouse gas emissions in order to achieve the assumed national targets and the adaptation to the effects of climate change. The Ministry of Environment and Climate Change is monitoring the process of adaptation to the effects of climate change. There is no defense sector among the 13 sectors vulnerable to the negative

*The unitary risk assessment methodology and the integration of the sectorial risk assessments* aim to provide a common framework for analysis for the sectorial risk assessments. It provides information on the types of risks present on the territory of Romania. The methodology defines the stages for the identification of scenarios, the construction of risk scenarios as well as the criteria for their prioritization and selection in order to establish the representative scenarios

At a community level, the European Commission has initiated starting with 2010 a process of creating a unitary methodological framework for risk assessment to improve the capacity of member states to respond by means of prevention, preparedness, and intervention measures to identified risks. This approach also aims to better manage and distribute resources for the effective and efficient management of disastrous events in the European Union (EU).

• Using best practices of international standards in the EU and developing a common risk

• Creating a risk assessment tool for institutions/organizations with disaster management

• Developing knowledge on disaster prevention policies at different administrative levels.

• Increasing the awareness of the population about disaster prevention measures.

• Providing information to establish a European disaster-assistance capacity database.

• Providing resource information on how to prioritize and allocate investments to prevent,

These directions are embodied in the security plans in the form of structured procedures on the following stages: identification of important elements; performing a risk analysis based on major threat scenarios, on vulnerabilities and potential impact; and identifying, selecting, and implementing technical and organizational solutions. Critical military infrastructures can be assessed against the level of preparedness to the threats posed by climate change based on

The guidelines formulated at the level of the European Commission are mainly [5]:

correlation of resources with needs).

26 Risk Assessment

impacts of climate change [3].

assessment approach.

responsibilities.

the following indicators:

• The way they perceive the threat.

to be subjected to the evaluation process [4].

prepare, and establish rehabilitation measures.

• The adaptive-preventive capacity against threats.

• The adaptive-reactive capacity in case of threat manifestation.

#### *Air temperature:*

### *Rainfall:*

### **2. The natural risk assessment and analysis process**

#### **2.1. The risk of natural events**

Natural hazards are extreme manifestations of natural phenomena with direct implications on each person's life, society, and the environment as a whole [8]. Between natural phenomena, climatic conditions are the subject of this analysis (e.g., storms, floods, tornadoes, extreme temperatures, drought, frost).

The natural risk, in terms of the possibility of occurrence of unwanted natural events, is defined as a function of assets, threats, and vulnerabilities. Asset, in the military organization, represents those values that the organization needs to fulfill its mission. If these values (e.g., people, information, facilities, activities, operations) have a significant weight in the accomplishment of the mission, and their total or partial loss would have serious consequences for the organization as a whole, then they are considered critical. Vulnerability is defined as an asset breach that can be exploited with negative effects on the organization's interests. Threat is the situation that can exploit a vulnerability [9].

Individual risks are related to the likelihood that a natural initiator event develops to a scenario with credible consequences. Thus, the notion of climatic vector is introduced to describe some aspects of the climate that are known to have significant destructive potential and disruptive potential over military infrastructure and operations.

Vectors, such as heavy snow, ice, strong winds, heavy rain, extreme temperatures, or electrical discharges, can cause material damage, military technique damage, and disruption of the communications system. They can also quickly have a cascading effect on the military system as a whole, with an effect on the infrastructure of interest. Climatic vectors were identified based on the destructive potential of infrastructures and the disruptive potential of intervention actions (**Table 2**). These climatic vectors are described to provide an overview of climate change in the central area of Romania.

The value scales included in the description are in line with the specific climate regime of Romania, according to the National Meteorological Administration (NMA), and the uncertainty level was estimated based on the climate change risks included in the National Climate Change Strategy 2013–2020 [10].

Climate change, highlighted by both the effects of immediate catastrophic events as well as a part of a slower process, stimulates proactive decisions to reduce existing vulnerabilities and avoid future damage. Critical military infrastructures can be evaluated in relation to the level of preparedness to climate change threats based on the following indicators: how to perceive the threat; the ability to deal with the threat; and the ability to respond and adapt to threats.

**Table 2.** Identification of climatic vectors.

*Air temperature:*

28 Risk Assessment

*Rainfall:*

season, the heating does not exceed 1°C.

of the length of the Romanian hydrographic network.

**2. The natural risk assessment and analysis process**

in the mountain range.

**2.1. The risk of natural events**

temperatures, drought, frost).

is the situation that can exploit a vulnerability [9].

ruptive potential over military infrastructure and operations.

• An increase in the average monthly air temperature is projected in November and December and in the hot period of the year (May–September), about 1°C, somewhat higher values (up to 1.4–1.5 1°C) in the mountains, in the south and west of the country; during the cold

• The average annual heating in the country is between 0.7 and 1.1°C, with the highest values

• A decrease in monthly precipitation volumes is projected for the period 1961–1990, especially in the winter months (December, February), an increase in October, and in June a slight increase in the mountains and declines are projected in the hills and plains areas. • 3.5% of Romania's surface area and 6% of the population would be affected by floods in a scenario with a probability of production once every 100 years; the 375 floodplains are located on 330 rivers and contain 16,000 km of flowing water, which represent about 20%

Natural hazards are extreme manifestations of natural phenomena with direct implications on each person's life, society, and the environment as a whole [8]. Between natural phenomena, climatic conditions are the subject of this analysis (e.g., storms, floods, tornadoes, extreme

The natural risk, in terms of the possibility of occurrence of unwanted natural events, is defined as a function of assets, threats, and vulnerabilities. Asset, in the military organization, represents those values that the organization needs to fulfill its mission. If these values (e.g., people, information, facilities, activities, operations) have a significant weight in the accomplishment of the mission, and their total or partial loss would have serious consequences for the organization as a whole, then they are considered critical. Vulnerability is defined as an asset breach that can be exploited with negative effects on the organization's interests. Threat

Individual risks are related to the likelihood that a natural initiator event develops to a scenario with credible consequences. Thus, the notion of climatic vector is introduced to describe some aspects of the climate that are known to have significant destructive potential and dis-

Vectors, such as heavy snow, ice, strong winds, heavy rain, extreme temperatures, or electrical discharges, can cause material damage, military technique damage, and disruption of the

#### **2.2. Natural risk assessment model**

Risk assessment is the process of evaluating: what can happen, caused by what, and which can be the maximum impact. The outcome of the process may take the form of a qualitative measure of the potential of losses resulting from the occurrence of uncertain events in a specific period of time [11].

Standard or nonstandardized methods or techniques may be used to assess the level of risk, but these must include: name/type of method; initial assumptions; and approximations. The natural risk assessment process includes a preliminary step (quantitative analysis) and a detailed step (quantitative analysis). For the developed natural risk assessment model, we used the risk matrix method (in order to make possible the hierarchy of events based on the level of risk) and the checklist (to identify the vulnerabilities of the infrastructure) at the preliminary stage. In the detailed step, we used analysis of barriers protection (in terms of occurrence frequency of initiator event and multiplication factor of consequences).

The proposed model is based on the assumption that the risk has two characteristics: the uncertainty (the probability of occurrence of the event) and the negative effect (the seriousness of the consequences) [12]. Thus, the level of risk can be interpreted in terms of deviation from the desired final state, and the maximum deviation is the most unfavorable possible condition.

In order to increase the level of protection against the climate change of critical infrastructure in general and critical military infrastructures in particular, we have designed the following milestones: the definition of zonal climatic conditions; the identification of the infrastructure assets and critical activities; and the assessment of the natural risks (based on the coefficient of the asset's importance, the vulnerability level and the multiplier factors, risk prioritization, identification of adaptation strategies, monitoring, and reassessing risks).

At this step, the list of infrastructure assets and specific critical activities/operations is drawn up. Thus, a specific list of military aviation units has been pre-defined, with the possibility to be customized for any other type of objective (**Table 3**).

The risk assessment model is based on the assignment of relative risk scores (*Rs*) for each infrastructure asset or specific activity/operation that may be affected by the selected climatic vectors. The level of importance (*Li*), vulnerability (*Vu*), and multiplier factor (*Mf*) are estimated to be between 1 and 3. The risk estimation formula is a simple multiplication, and it is expressed in Eq. (1).

$$Rs = Li \times Vu \times Mf \tag{1}$$

The importance factor of the specific infrastructure/operation asset is defined according to the role within the system, based on the following indicators: interconnectivity with other subsystems, recovery costs, security and safety, legislative requirements. Thus, three levels of importance are defined in **Table 4**.

Vulnerability is defined in terms of the sensitivity of an infrastructure asset specific to a climatic vector. Thus, vulnerability is dependent on the strength of the infrastructure, the Natural Risk Management to Protect Critical Infrastructures: A Model for Active Learning http://dx.doi.org/10.5772/intechopen.70606 31

**Table 3.** List of critical infrastructure assets and activities.

**1** Loss of assets/disruption would have a negligible impact on the fulfillment of the mission

**2** Loss of assets/discontinuation of operations would significantly impede the fulfillment of the mission

**3** Loss of assets/discontinuation of operations would hinder the fulfillment of the mission

**Table 4.** Defining levels of importance.

**2.2. Natural risk assessment model**

cific period of time [11].

30 Risk Assessment

condition.

expressed in Eq. (1).

importance are defined in **Table 4**.

Risk assessment is the process of evaluating: what can happen, caused by what, and which can be the maximum impact. The outcome of the process may take the form of a qualitative measure of the potential of losses resulting from the occurrence of uncertain events in a spe-

Standard or nonstandardized methods or techniques may be used to assess the level of risk, but these must include: name/type of method; initial assumptions; and approximations. The natural risk assessment process includes a preliminary step (quantitative analysis) and a detailed step (quantitative analysis). For the developed natural risk assessment model, we used the risk matrix method (in order to make possible the hierarchy of events based on the level of risk) and the checklist (to identify the vulnerabilities of the infrastructure) at the preliminary stage. In the detailed step, we used analysis of barriers protection (in terms of occur-

The proposed model is based on the assumption that the risk has two characteristics: the uncertainty (the probability of occurrence of the event) and the negative effect (the seriousness of the consequences) [12]. Thus, the level of risk can be interpreted in terms of deviation from the desired final state, and the maximum deviation is the most unfavorable possible

In order to increase the level of protection against the climate change of critical infrastructure in general and critical military infrastructures in particular, we have designed the following milestones: the definition of zonal climatic conditions; the identification of the infrastructure assets and critical activities; and the assessment of the natural risks (based on the coefficient of the asset's importance, the vulnerability level and the multiplier factors, risk prioritization,

At this step, the list of infrastructure assets and specific critical activities/operations is drawn up. Thus, a specific list of military aviation units has been pre-defined, with the possibility to

The risk assessment model is based on the assignment of relative risk scores (*Rs*) for each infrastructure asset or specific activity/operation that may be affected by the selected climatic vectors. The level of importance (*Li*), vulnerability (*Vu*), and multiplier factor (*Mf*) are estimated to be between 1 and 3. The risk estimation formula is a simple multiplication, and it is

The importance factor of the specific infrastructure/operation asset is defined according to the role within the system, based on the following indicators: interconnectivity with other subsystems, recovery costs, security and safety, legislative requirements. Thus, three levels of

Vulnerability is defined in terms of the sensitivity of an infrastructure asset specific to a climatic vector. Thus, vulnerability is dependent on the strength of the infrastructure, the

*Rs = Li × Vu × Mf* (1)

rence frequency of initiator event and multiplication factor of consequences).

identification of adaptation strategies, monitoring, and reassessing risks).

be customized for any other type of objective (**Table 3**).

adaptability to a specific vector, and the expected changes. Prospects from which vulnerability can be addressed include: age, physical condition, location of repairs and maintenance (for infrastructure assets), personnel training, the existence and updating of procedures, and the time elapsed since the last update (for specific activities/operations). Vulnerability is calculated by multiplying the consequences of a climatic vector with the probability of producing consequences on an infrastructure asset or specific activity/operation. Vulnerability levels are detailed in **Table 5**.

The multiplication factor is defined in terms of the negative weather evolution of climatic conditions, being expressed by the time variation of the climatic vectors. To define the variation of the selected climatic vector, the historical data provided by the National Meteorological Institute for the Brasov station were used. On this data, the FORECAST.ETS function (version AAA of the Exponential Smoothing algorithm with a 95% preselected confidence interval) was applied to Excel 2016 in order to estimate the evolution of the medium-term climatic vector (10 and 25 years) (**Figure 1**).

**Table 5.** Defining the levels of vulnerability.

**Figure 1.** Capture from Forecast sheet excel 2016 for "Stormy days".

The multiplication factor is determined by the estimated number of days of variation of the climatic vector toward unfavorable conditions (**Table 6**).

In order to represent the risk matrix associated with each selected infrastructure asset and selected specific activity/operation, the risk matrix with three regions is used (**Table 7**). These regions are acceptable (1, 2, and 3), tolerable (4, 6, 8, and 9), and unacceptable (12, 18, and 27).

This is the interpretation of the three risk areas: the red region (the risk is considered unacceptable, regardless of the benefits it could bring, the treatment of risk is imperative regardless of costs); the yellow region (the risk is tolerable only if the decrease is impossible or if the reduction costs exceed the value of the damage); and the green area (the level of risk is considered negligible and monitoring is required).

**Table 6.** Defining the multiplier factor.

**<sup>1</sup>** Vector variation less than 1 day per year

**Table 7.** Risk matrix.

The multiplication factor is determined by the estimated number of days of variation of the

In order to represent the risk matrix associated with each selected infrastructure asset and selected specific activity/operation, the risk matrix with three regions is used (**Table 7**). These regions are acceptable (1, 2, and 3), tolerable (4, 6, 8, and 9), and unacceptable (12, 18, and 27). This is the interpretation of the three risk areas: the red region (the risk is considered unacceptable, regardless of the benefits it could bring, the treatment of risk is imperative regardless of costs); the yellow region (the risk is tolerable only if the decrease is impossible or if the reduction costs exceed the value of the damage); and the green area (the level of risk is

climatic vector toward unfavorable conditions (**Table 6**).

**Figure 1.** Capture from Forecast sheet excel 2016 for "Stormy days".

**1** The specific asset/operation is unlikely to be affected by the climatic vector **2** The specific asset/operation is likely to be affected by the climatic vector

**Table 5.** Defining the levels of vulnerability.

32 Risk Assessment

**3** The specific asset/operation is likely to be significantly affected by the climate vector

considered negligible and monitoring is required).

**1** Vector variation less than 1 day per year

**2** Vector variation ranging from 1 to 3 days per year

**3** Vector variation greater than 3 days per year

**Table 6.** Defining the multiplier factor.

#### **2.3. Natural risk analysis**

A risk analysis is a proactive approach that consists of identification of possible negative events or situations, determination of cause-and-effect relationships, and evaluation of various outcomes under different assumptions. Risk analysis becomes important not only from the perspective of increasing risk assessment utility for decision-making, but also from the perspective of improved techniques used in risk assessment [13].

For designing adaptation strategies, it is taken into account the impact of the climatic vector on the operational requirements of the specific infrastructure/activity asset and the level of risk (which determines the priority of the action—immediate, medium, and low). Effective management of adaptation strategies is done by drawing up a risk sheet (**Table 8**).

Immediate priority risks are those where the infrastructure asset or specific activity/operation is essential for the entire military system, the climate impact is present, and the evolution toward more dangerous conditions is high and imminent. In these situations, it is imperative to immediately adopt the identified adaptation strategies.

Also, if some unidentified weaknesses become apparent during specific activities/operations, updating information, risk prioritization, and adjustments to the adaptation strategies for the major threats are made.

**Table 8.** Risk sheet model.

Checklists may be drawn up in order to facilitate the selection of adaptation strategies by keeping the following records: the infrastructure assets or the specific activities/operations that will be affected, the priority with which the strategy is to be implemented, who is responsible for that risk.

This qualitative approach provides an initial picture of the risk exposure of military objectives, which of the risks require action, training, or monitoring. The action lines for risk management include: reduction of risk exposure (structural protection); reducing vulnerability (prevention); improving resistance to change (forms of training and education); reorganization of the military objective; and training, response, and recovery (emergency services).

In order to have a complete picture of the issue, risk analysis should also include a justification of the cost of the solutions identified in relation to the reduction of the level of risk. Thus, the cost-benefit analysis is carried out for each adaptation strategy, after being evaluated from the point of view of effectiveness, feasibility, and action priority [14].

The challenge is not only to determine the cost of solutions but also to determine the cost needed to achieve the system's resilience to natural disaster events. First of all, it is a question of effectively allocating existing resources to bring the risk to an acceptable level. In most cases, the cost of adaptation strategies is more tangible than the cost of benefits.

In this respect, a model for calculating the potential benefits for an identified solution was proposed by Cioacă et al. [15]. This model, initially applied to assess security investments to mitigate terrorist risk, can be easily adapted and applied in risk analyses of natural disaster events [15].

Thus, the estimate of the benefit (*B*) corresponding to the introduction of a package of measures *A* at the level of an infrastructure element *i* is based on the effect/impact on the level of risk (the difference between the initially assessed risk level—*Rs*<sup>0</sup> and the assessed level of risk after the implementation of the adaptation solution—*Rs*A) and the cost of avoided consequences (*CCA*) (Eq. (2)).

$$\mathbf{B}\_{l}^{A} = \mathbf{P}\_{l}^{A} \cdot \frac{\mathbf{R}s\_{o} - \mathbf{R}s\_{A}}{\mathbf{R}s\_{o}} \cdot \mathbf{C} \mathbf{C} \mathbf{A}^{A} \tag{2}$$

where *Pi A* represents the priority of adopting package *A* on infrastructure *i*, based on the following scale of values: 1, low; 2, medium; and 3, immediate. The *CCA* has a human component (cost of life saved by application *A*) and a material component (material damage saved according to the percentage of saved infrastructure and accounting value attributed).

#### **3. Natural event monitoring**

This section, which integrates the adaptive-reactive approach to risk management, is an active learning tool by testing the natural risk assessment model on simulated scenarios under laboratory conditions. The scenario considered is the post-storm assessment of the explosion hazard in the fuel storage area of a military base.

The section for monitoring ongoing natural events is based on the technical possibilities offered by:

Arduino UNO is an open-source processing platform based on flexible and simple software and hardware. It consists of a small-scale platform built around a signal processor and is capable of retrieving data from the environment through a series of sensors. The processor is able to run written code in a programming language that is very similar to C++:

#include <idDHT11.h>.

int. idDHT11pin = 2; //Digital pin for communications.

int. idDHT11intNumber = 0; //interrupt number (must be the one that use the previous defined pin (see table above).

//declaration.

Checklists may be drawn up in order to facilitate the selection of adaptation strategies by keeping the following records: the infrastructure assets or the specific activities/operations that will be affected, the priority with which the strategy is to be implemented, who is respon-

This qualitative approach provides an initial picture of the risk exposure of military objectives, which of the risks require action, training, or monitoring. The action lines for risk management include: reduction of risk exposure (structural protection); reducing vulnerability (prevention); improving resistance to change (forms of training and education); reorganization of the military objective; and training, response, and recovery (emergency

In order to have a complete picture of the issue, risk analysis should also include a justification of the cost of the solutions identified in relation to the reduction of the level of risk. Thus, the cost-benefit analysis is carried out for each adaptation strategy, after being evaluated from

The challenge is not only to determine the cost of solutions but also to determine the cost needed to achieve the system's resilience to natural disaster events. First of all, it is a question of effectively allocating existing resources to bring the risk to an acceptable level. In most

In this respect, a model for calculating the potential benefits for an identified solution was proposed by Cioacă et al. [15]. This model, initially applied to assess security investments to mitigate terrorist risk, can be easily adapted and applied in risk analyses of natural disaster events [15].

Thus, the estimate of the benefit (*B*) corresponding to the introduction of a package of measures *A* at the level of an infrastructure element *i* is based on the effect/impact on the level

risk after the implementation of the adaptation solution—*Rs*A) and the cost of avoided conse-

*Rs*<sup>0</sup> <sup>−</sup> *Rs* \_\_\_\_\_\_\_*<sup>A</sup> Rs*<sup>0</sup>

lowing scale of values: 1, low; 2, medium; and 3, immediate. The *CCA* has a human component (cost of life saved by application *A*) and a material component (material damage saved

This section, which integrates the adaptive-reactive approach to risk management, is an active learning tool by testing the natural risk assessment model on simulated scenarios

according to the percentage of saved infrastructure and accounting value attributed).

represents the priority of adopting package *A* on infrastructure *i*, based on the fol-

and the assessed level of

∙ *CCAA* (2)

the point of view of effectiveness, feasibility, and action priority [14].

of risk (the difference between the initially assessed risk level—*Rs*<sup>0</sup>

*<sup>A</sup>* = *Pi A* ∙

cases, the cost of adaptation strategies is more tangible than the cost of benefits.

sible for that risk.

34 Risk Assessment

services).

quences (*CCA*) (Eq. (2)).

where *Pi A*

*Bi*

**3. Natural event monitoring**

void dht11\_wrapper(); //must be declared before the lib initialization.

//Lib instantiate.

idDHT11 DHT11(idDHT11pin,idDHT11intNumber,dht11\_wrapper);

float sensor = A0;

float gas\_value;

void setup().

{

pinMode(sensor,INPUT);

Serial.begin(9600);

Serial.println("Academia Fortelor Aeriene GAZTEMP MONITORING");

Serial.print("LIB version: ");

Serial.println(IDDHT11LIB\_VERSION);

Serial.println("---------------").

**Figure 2.** Integrated architecture aerial vector sensors. (1) Smoke sensor and flammable gases; (2) Arduino UNO; (3) radio transmitter; and (4) quadcopter.

The smoke and flammable gas sensor has the ability to detect the following flammable gases: butane, propane, hydrogen, and methane. The presence of these gases in the air is measured in parts per million (ppm). In **Table 9**, the lower explosion limit (LEL) and the upper explosion limit (UEL) and the immediate danger to life or health (IDLH) are presented.

Depending on the explosion limits specific to each type of gas detected, the hazard grid was developed on four levels: Green, Yellow, Orange, Red (**Table 10**).

Quadcopter is a customized solution developed in the Autonomous Aerial Systems Laboratory. Testing of air vector functionality and integrated sensors was performed within the "Henri Coanda" Air Force Academy on a source of heat and smoke (**Figure 3a**), based on a flight planner (**Figure 3b**).

Some of the measurement results are represented in **Table 11**. A variation in the concentration of flammable gases can be observed, with a peak of 983 ppm at melting point 10.

**Table 9.** Lower and upper explosion limits.

Natural Risk Management to Protect Critical Infrastructures: A Model for Active Learning http://dx.doi.org/10.5772/intechopen.70606 37

**Table 10.** Interpretation of monitoring data.

The smoke and flammable gas sensor has the ability to detect the following flammable gases: butane, propane, hydrogen, and methane. The presence of these gases in the air is measured in parts per million (ppm). In **Table 9**, the lower explosion limit (LEL) and the upper explosion limit (UEL) and the immediate danger to life or health (IDLH) are

**Figure 2.** Integrated architecture aerial vector sensors. (1) Smoke sensor and flammable gases; (2) Arduino UNO; (3)

Depending on the explosion limits specific to each type of gas detected, the hazard grid was

Quadcopter is a customized solution developed in the Autonomous Aerial Systems Laboratory. Testing of air vector functionality and integrated sensors was performed within the "Henri Coanda" Air Force Academy on a source of heat and smoke (**Figure 3a**), based on

Some of the measurement results are represented in **Table 11**. A variation in the concentration

of flammable gases can be observed, with a peak of 983 ppm at melting point 10.

**Gas LEL (ppm) UEL (ppm) IDLH (ppm)**

Hydrogen 40,000 750,000 Asphyxiant Methane 50,000 150,000 Asphyxiant

Butane 16,000 84,000 – Propane 21,000 95,000 2100

developed on four levels: Green, Yellow, Orange, Red (**Table 10**).

presented.

36 Risk Assessment

a flight planner (**Figure 3b**).

radio transmitter; and (4) quadcopter.

**Table 9.** Lower and upper explosion limits.

**Figure 3.** Testing weather sensors: (a) photo and (b) capture from mission planner.

**Table 11.** Test results.

### **4. Decision support platform**

The information provided in the risk analysis and event monitoring (if the option is activated) are integrated into a decision support platform using the Delphi 7 program. The decisional architecture was designed to meet both user requirements (modular, flexible, scalable) as well as the need for overlapping with the stages of the risk management process.

The platform is designed to: easily identify the infrastructure asset of the climate vector in real-time and to identify the medium-term evolution; to update the risk indicators (**Figure 4**); to visualize the level of risk; to be able to save a risk report (data about the climatic vector, the infrastructure asset, the level of risk, the severity of the impact, and the adaptation strategies).

User input values are essential to delimit the risk classes according to the scales from **Tables 4**–**6**. For situations of inapplicability, the value 1 is entered. To facilitate the accurate determination of the vulnerability level, scenario analysis is performed.

For the correct interpretation of the results provided by the support decision-making platform, it is very important to understand the following: the growth or decrease trend of the climatic vector in the next 10 or 25 years, respectively; the projected climate change for the next 10 and 25 years; the level of uncertainty reported for each climatic vector; communicating best practices identified at regional level from other critical infrastructures. For the event monitoring section, data are available to the user after executing the mission/monitoring in .txt or.avi format. Once downloaded, they are automatically retrieved and displayed in the Monitoring Report (**Figure 5**).

This section provides the possibility to save a risk report by creating a text version (.txt). For the correct interpretation of the results provided by the support decision-making platform, it is very important to understand the following: the growth or decrease trend of the climatic

**Figure 4.** Definition of risk indices.

Natural Risk Management to Protect Critical Infrastructures: A Model for Active Learning http://dx.doi.org/10.5772/intechopen.70606 39

**Figure 5.** Display air monitoring report.

vector in the next 10 or 25 years; the projected climate change for the next 10 and 25 years; the level of uncertainty reported for each climatic vector; communicating best practices identified at regional level to and from other military objectives.

#### **5. Conclusions**

**4. Decision support platform**

the vulnerability level, scenario analysis is performed.

adaptation strategies).

38 Risk Assessment

Monitoring Report (**Figure 5**).

**Figure 4.** Definition of risk indices.

The information provided in the risk analysis and event monitoring (if the option is activated) are integrated into a decision support platform using the Delphi 7 program. The decisional architecture was designed to meet both user requirements (modular, flexible, scalable) as well

The platform is designed to: easily identify the infrastructure asset of the climate vector in real-time and to identify the medium-term evolution; to update the risk indicators (**Figure 4**); to visualize the level of risk; to be able to save a risk report (data about the climatic vector, the infrastructure asset, the level of risk, the severity of the impact, and the

User input values are essential to delimit the risk classes according to the scales from **Tables 4**–**6**. For situations of inapplicability, the value 1 is entered. To facilitate the accurate determination of

For the correct interpretation of the results provided by the support decision-making platform, it is very important to understand the following: the growth or decrease trend of the climatic vector in the next 10 or 25 years, respectively; the projected climate change for the next 10 and 25 years; the level of uncertainty reported for each climatic vector; communicating best practices identified at regional level from other critical infrastructures. For the event monitoring section, data are available to the user after executing the mission/monitoring in .txt or.avi format. Once downloaded, they are automatically retrieved and displayed in the

This section provides the possibility to save a risk report by creating a text version (.txt). For the correct interpretation of the results provided by the support decision-making platform, it is very important to understand the following: the growth or decrease trend of the climatic

as the need for overlapping with the stages of the risk management process.

The impact created by such a scientific approach beyond the benefits of active innovationbased learning can also be assessed in potentially applicative terms: increasing the resilience of critical military infrastructures to natural events with catastrophic effects in the context of climate change. Future research directions include the removal of the current limitations of this innovative solution: it is necessary to improve the databases on infrastructure assets, the potential impact of the climatic vectors and the adaptation strategies; the application does not evaluate the cumulative effects of multiple vectors; data recorded by sensors integrated in aerial vectors are not available in real time.

The impact of this scientific approach is found in four main directions: increasing the capacity to understand the dynamics of natural risks from climate change and its impact on infrastructure assets/specific operations in the Romanian Air Force infrastructures; assessing the effectiveness of current plans in the context of future needs; optimizing the allocation of resources needed to initiate the climate change adaptation planning process; and increasing the resilience of critical military infrastructures in the Air Force to natural events with catastrophic effects in the context of climate change.

The solution can also significantly improve the planning process at the level of each military objective, which is currently taking place within an adaptive-reactive management. Existing planning documents do not provide opportunities to incorporate adaptation strategies to climate change in the short, medium, and long term. These documents are drawn up in the form of action orders whose triggering factor is the occurrence of an event or alerts issued by the NMA.

From the point of view of adaptive-preventive management, it is necessary to develop Climate Change Adaptation Plans (PASCs) at the level of each critical military infrastructure. The military objectives that have been endowed or are in the process of endowment with modern military technique represent an emergency. This process involves the initiation of some infrastructure projects.

This risk management approach in critical military infrastructures also has a number of limitations that constitute future research directions: for transformation into a functional model, it is necessary to improve the built databases on infrastructure assets, the potential impact of climatic vectors and adaptation strategies; information is not exhaustive, for special situations (e.g., hangars design) further studies and analysis are required; the model does not assess the cumulative effects of several vectors on the same infrastructure or specific operation; data recorded by weather sensors integrated into the air vector (temperature, humidity, flammable gas) should be available in real time also to the institutions with responsibilities in emergency management.

### **Acknowledgements**

This research was supported by the Romanian National Authority for Scientific Research CNCSUEFISCDI in MAPIAM project "Modular Aircraft Platform for Intelligent Atmospheric Monitoring," Program 2—Increasing the Competitiveness of the Romanian Economy through Research, Development and Innovation, Domain 3—Energy, Environment and Climate Change. We are thankful to our colleague Sebastian Pop who provided expertise that greatly assisted the research in the field of aerial vector operation.

### **Author details**

Catalin Cioaca\*, Vasile Prisacariu and Mircea Boscoianu

\*Address all correspondence to<EMAIL_ADDRESS>
"Henri Coanda" Air Force Academy, Brasov, Romania

### **References**

[3] Romanian Environment and Forests Ministry. National Strategy of Romania on Climate Change 2013-2020 [Internet]. 2012 [Updated: 2012]. Available from: http://www.mmediu. ro/beta/wp-content/uploads/2012/10/2012-10-05-Strategia\_NR-SC.pdf [Accessed: May 16, 2016]

From the point of view of adaptive-preventive management, it is necessary to develop Climate Change Adaptation Plans (PASCs) at the level of each critical military infrastructure. The military objectives that have been endowed or are in the process of endowment with modern military technique represent an emergency. This process involves the initiation of some infrastructure

This risk management approach in critical military infrastructures also has a number of limitations that constitute future research directions: for transformation into a functional model, it is necessary to improve the built databases on infrastructure assets, the potential impact of climatic vectors and adaptation strategies; information is not exhaustive, for special situations (e.g., hangars design) further studies and analysis are required; the model does not assess the cumulative effects of several vectors on the same infrastructure or specific operation; data recorded by weather sensors integrated into the air vector (temperature, humidity, flammable gas) should be available in real time also to the institutions with responsibilities in emergency

This research was supported by the Romanian National Authority for Scientific Research CNCSUEFISCDI in MAPIAM project "Modular Aircraft Platform for Intelligent Atmospheric Monitoring," Program 2—Increasing the Competitiveness of the Romanian Economy through Research, Development and Innovation, Domain 3—Energy, Environment and Climate Change. We are thankful to our colleague Sebastian Pop who provided expertise that greatly

[1] Romanian Government. Decision no 718 for the Approval of the National Strategy on Critical Infrastructure Protection [Internet]. 2011 [Updated: 2011]. Available from: http://

[2] Romanian Government. Decision no 1198 Regarding he Designation of National Critical Infrastructures [Internet]. 2012 [Updated: 2012]. Available from: http://ccpic.mai.gov.ro/

ccpic.mai.gov.ro/docs/HGR718\_2011.pdf [Accessed: April 23, 2016]

docs/HGR%201198\_2012.pdf [Accessed: May 4, 2016]

assisted the research in the field of aerial vector operation.

Catalin Cioaca\*, Vasile Prisacariu and Mircea Boscoianu \*Address all correspondence to<EMAIL_ADDRESS>"Henri Coanda" Air Force Academy, Brasov, Romania

projects.

40 Risk Assessment

management.

**Acknowledgements**

**Author details**

**References**

**Provisional chapter**

### **Earthquake Culture: A Significant Element in Earthquake Disaster Risk Assessment and Earthquake Disaster Risk Management Earthquake Culture: A Significant Element in Earthquake Disaster Risk Assessment and Earthquake Disaster Risk Management**

DOI: 10.5772/intechopen.70434

Michaela Ibrion Michaela Ibrion Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70434

#### **Abstract**

This book chapter brings to attention the dramatic impact of large earthquake disasters on local communities and society and highlights the necessity of building and enhancing the earthquake culture. Iran was considered as a research case study and fifteen large earthquake disasters in Iran were investigated and analyzed over more than a centurytime period. It was found that the earthquake culture in Iran was and is still conditioned by many factors or parameters which are not integrated and do not work harmoniously towards building and sustaining an earthquake culture in Iran. A historical possibility of an earthquake culture in Iran was mainly severed by culture, especially beliefs, strong geopolitics in Iran and in Middle East, a complex and dynamic political landscape in Iran, foreign invasions and wars. However, there is a great potential in Iran for the earthquake culture to be built and developed. The earthquake culture is recommended to be integrated within earthquake disaster risk assessment and earthquake disasters risk management studies which are performed and carried out in Iran and other countries at seismic risk. The contribution of this book chapter is towards the earthquake disasters studies and policies for the countries at earthquake risk.

**Keywords:** earthquake, earthquake culture, earthquake disaster risk assessment, earthquake disaster risk management, Iran, earthquake disaster risk reduction

### **1. Introduction**

Earthquakes are the manifestation of a living Earth [1] and occur at "unpredicted times and in unpredicted places" ([2], p. 352). Their rapid and dramatic effects on nature, culture and on unprepared communities and societies can cause the "archetypal sudden-impact disaster"

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

with high death tolls, injuries and massive destructions ([3], p. 42). Earthquake disasters claim the highest number of lives among other type of disasters in the world. Nowadays, earthquake disaster risk reduction is a key term within disaster research arena. Earthquake disaster preparedness is a highly nonlinear phenomenon and can bring huge positive results on earthquake disaster risk reduction. Even small steps can significantly reduce the death tolls and injuries. Moreover, the focus needs to be shifted from response and recovery to prevention and mitigation, building resilience, reduction of risk to acceptable or tolerable levels, implementation of lessons from past disasters, past experiences and failures [4–6].

This research study brings to attention the dramatic impact of large earthquake disasters on society and local communities in Iran and particularly emphasizes the necessity of investigation and the importance of building an earthquake culture in Iran. Moreover, highlights the necessity to integrate the earthquake culture within the framework of earthquake disaster risk assessment and earthquake disaster risk management.

The following sections provide theoretical insights about risk, risk assessment, risk management, and earthquake culture. Further on, an investigation of 15 case studies of earthquakes and earthquake disasters in Iran over more than a century time-period (1909–2014) is presented. For investigation of the earthquake culture in Iran, a geo-historical and socio-cultural study was performed with an emphasis on an interdisciplinary approach. Narratives of earthquake disasters survivors, archival documents, earthquake field reports, cartographic and various academic studies were used for this study.

### **2. Risk**

Risk can be basically defined as the likelihood multiplied by consequences or Hazard x Potential worth of loss [7]. Furthermore, with reference to the fundamental definitions of risk, Faber [8] and Lacasse et al. [5] advised that risk is seen as an equation such as R = P · C, where R is Risk, P is Probability that an event will occur multiplied by expected Consequences or severity of adverse effects to life, health, properties and environment.

We live in a "world risk society" ([9], p. 1) where it is out of reality and practice to eliminate the risk. The disaster risk can never be eliminated, but it can be reduced to levels which are acceptable or tolerable by society [5, 10]. Moreover, Lacasse and Nadim [7] and Lacasse [10] warned that societies proved to be very less tolerant of an event where a huge number of lives is lost all of a sudden, compared with the same number of lives which is lost over the time in a number of separate events. Earthquake disasters are example of such events which test the tolerance and acceptance limits from communities and society [11, 12]. Risk can be expressed as individual risk and societal risk to people and assets. Societal risk can be presented through F-N diagrams or F-N curves expressing the risk level that a society is apparently willing to accept. Acceptable risk is the level of risk which a society aims to achieve it, and the tolerable risk refers to the risk level that can be reached after compromises in order to gain some benefits. The societal acceptable risk levels vary among national codes and standards around the world. The F-N curves relate to the annual or other temporal occurrence probability (F) of an event capable for causing (N), or more fatalities. The term N can be replaced by other quantitative measures of consequences, for instance, costs. As a note, the F-N curves offer statistical observations and not the acceptable or tolerable thresholds. The F-N curves can be also used to describe the safety levels of particular facilities. Moreover, the F-N curves offer a good illustration for comparison of the calculated probabilities with observed frequencies of failure for facilities [5, 7, 10].

Very often, the risk analysis is seen as a magic wand that will transform the unpredictable in predictable [13]. "The risk of risk analysis" and the ontological matter that an uncertainty even analyzed and calculated is still an uncertainty was also emphasized ([14], p. 810). Woo [15] highlighted that uncertainty is an inexorable feature of human world and brought to attention the requirement to consider both the epistemic and aleatory uncertainty. The relation between risk, space and time needs to be also considered as a risk analysis "only reflects the situation at a certain point in time, and for a given location with a distinct spatial dimension of scale" ([16], p. 194). Interdisciplinary approaches have been seen as essential strategies for risk analysis and disaster risk reduction (DRR).

### **3. Risk assessment**

with high death tolls, injuries and massive destructions ([3], p. 42). Earthquake disasters claim the highest number of lives among other type of disasters in the world. Nowadays, earthquake disaster risk reduction is a key term within disaster research arena. Earthquake disaster preparedness is a highly nonlinear phenomenon and can bring huge positive results on earthquake disaster risk reduction. Even small steps can significantly reduce the death tolls and injuries. Moreover, the focus needs to be shifted from response and recovery to prevention and mitigation, building resilience, reduction of risk to acceptable or tolerable levels, imple-

This research study brings to attention the dramatic impact of large earthquake disasters on society and local communities in Iran and particularly emphasizes the necessity of investigation and the importance of building an earthquake culture in Iran. Moreover, highlights the necessity to integrate the earthquake culture within the framework of earthquake disaster risk

The following sections provide theoretical insights about risk, risk assessment, risk management, and earthquake culture. Further on, an investigation of 15 case studies of earthquakes and earthquake disasters in Iran over more than a century time-period (1909–2014) is presented. For investigation of the earthquake culture in Iran, a geo-historical and socio-cultural study was performed with an emphasis on an interdisciplinary approach. Narratives of earthquake disasters survivors, archival documents, earthquake field reports, cartographic and

Risk can be basically defined as the likelihood multiplied by consequences or Hazard x Potential worth of loss [7]. Furthermore, with reference to the fundamental definitions of risk, Faber [8] and Lacasse et al. [5] advised that risk is seen as an equation such as R = P · C, where R is Risk, P is Probability that an event will occur multiplied by expected Consequences or

We live in a "world risk society" ([9], p. 1) where it is out of reality and practice to eliminate the risk. The disaster risk can never be eliminated, but it can be reduced to levels which are acceptable or tolerable by society [5, 10]. Moreover, Lacasse and Nadim [7] and Lacasse [10] warned that societies proved to be very less tolerant of an event where a huge number of lives is lost all of a sudden, compared with the same number of lives which is lost over the time in a number of separate events. Earthquake disasters are example of such events which test the tolerance and acceptance limits from communities and society [11, 12]. Risk can be expressed as individual risk and societal risk to people and assets. Societal risk can be presented through F-N diagrams or F-N curves expressing the risk level that a society is apparently willing to accept. Acceptable risk is the level of risk which a society aims to achieve it, and the tolerable risk refers to the risk level that can be reached after compromises in order to gain some benefits. The societal acceptable risk levels vary among national codes and standards around the world. The F-N curves relate to the annual or other temporal

severity of adverse effects to life, health, properties and environment.

mentation of lessons from past disasters, past experiences and failures [4–6].

assessment and earthquake disaster risk management.

various academic studies were used for this study.

**2. Risk**

44 Risk Assessment

Lacasse [10] highlighted that risk assessment and reliability analysis are important tools for informed decision-making. According to Faber [8], risk assessment is seen as a comparison between estimated risk and accepted risk which initially was stated in risk acceptance criteria. Lacasse and Nadim [7] and Lacasse [10] warned that one of the most difficult tasks in risk assessment and risk management is the selection of risk acceptance criteria. Societies which experience very frequently geohazards may have a different risk acceptance level comparative with those societies which experience them rarely. In case that risk is not acceptable within the specified risk acceptance criteria, there are various ways for risk treatment: risk mitigation, risk reduction, risk transfer and risk acceptance [8].

Risk analysis and risk evaluation are basically seen as component parts of risk assessment. Risk analysis comprises hazard and risk identification, risk estimation and risk calculation. For robustness, increased accuracy and value of risk assessments it is required among others, to address the interconnection between physical and human systems, to consider both spatial and temporal scales, to address, analyze and communicate the uncertainties. Various formal and informal tools are utilized within the risk assessment [7, 10, 17]. Multi-risk assessments which studied the interaction and amplification of risk, cascading hazards, dynamic vulnerabilities to multi-risk have stirred a great interest, but still is a field yet to be developed and requires intensive collaboration and expertise from various disciplines [5, 7, 10].

With reference to the assessment of disaster risk in various countries around the world, there is the danger of oversimplifying and misunderstanding problems, priorities and concerns of people at risk. Moreover, there is a permanent struggle between the quantitative or the so-called technical risk approaches and the socio-cultural risk [18]. A cooperation among these approaches would be beneficial to disaster risk assessments.

### **4. Risk management**

Risk management integrates recognition and assessment of risk with development and implementation of adequate strategies of risk mitigation and risk reduction. Risk management represents a systematic application of policies, procedures and practices to the tasks of communication, consultation, establishing the context, identification, analysis, evaluation, monitoring and implementation of risk mitigation measures. Due to epistemic and aleatory uncertainty, risk management is decision-making under the condition of uncertainty. Likewise risk assessment, risk management requires also a multi-disciplinary approach [5, 7, 10].

Disaster risk management (DRM) confronted around the world various difficulties linked to political will, governance, available budget, implementation of legislation. Moreover, Okada [19] advised that DRM needs to have pre-disaster orientation instead of being focus on post-disaster phase, to take in consideration multiple hazards, to be closely linked to urban planning and management and to be inclusive and not limited only to governmental organizations and institutions, but to engage citizens, Non-Governmental Organizations (NGO)s, private companies, local communities, individuals. DRM needs to start from the local level or community level. Furthermore, for the present century, the integrated disaster risk management (IDRIM) is a necessary and required perspective in dealing with disaster risk.

### **5. State of the art on the earthquake culture**

Earthquake culture is particularly linked to earthquake hazard, earthquake risk, and earthquake disasters and refers to the capacities of communities and society of knowing to live with earthquake risk. Seismic culture, local seismic culture, seismic prevention cultures are examples of other interchangeable terms with the earthquake culture. The earthquake culture concept has roots in theoretical insights and research studies carried out during the time in different geographical places around the world.

Mileti and Darlington [20] analyzed the existence of an earthquake culture in the San Francisco Bay Area, years after the Loma Prieta 1989 earthquake. Earthquakes were not frequent in that specific area, but earthquake risk was known and local culture was abundant of accounts of the last and previous other earthquake disasters. Earthquake preparedness and readiness was seen as a part of local culture. Helly [21] emphasized that origins and development of local seismic cultures are influenced by frequency of earthquakes, their intensities, death toll and injuries, and extent of damages. Ferrigni [22] highlighted that a visible cultural adaptation to earthquakes is the seismic architecture or vernacular seismic architecture which develops over the time. However, Ferrigni [22] advised that earthquakes do not always generate a local seismic culture, particularly connected to earthquake resistant buildings. Nevertheless, according to Pierotti [23], the seismic culture can develop during the time, and the case of Japan is given as an example. In Japan, the memory of earthquake disasters has been kept alive through written records, oral accounts, legends, stories, through the lessons from earthquake disasters. Homan ([24], pp. 1–2) employed the hypothesis launched by the European University Centre for Cultural Heritage (CUEBC) that there is a correlation among frequency of earthquakes and local building practices. Consequently, two types of seismic cultures might develop: a "seismic prevention culture" when earthquakes are frequent and a "seismic culture of repairs" when earthquakes are low in frequency.

**4. Risk management**

46 Risk Assessment

Risk management integrates recognition and assessment of risk with development and implementation of adequate strategies of risk mitigation and risk reduction. Risk management represents a systematic application of policies, procedures and practices to the tasks of communication, consultation, establishing the context, identification, analysis, evaluation, monitoring and implementation of risk mitigation measures. Due to epistemic and aleatory uncertainty, risk management is decision-making under the condition of uncertainty. Likewise risk assess-

Disaster risk management (DRM) confronted around the world various difficulties linked to political will, governance, available budget, implementation of legislation. Moreover, Okada [19] advised that DRM needs to have pre-disaster orientation instead of being focus on post-disaster phase, to take in consideration multiple hazards, to be closely linked to urban planning and management and to be inclusive and not limited only to governmental organizations and institutions, but to engage citizens, Non-Governmental Organizations (NGO)s, private companies, local communities, individuals. DRM needs to start from the local level or community level. Furthermore, for the present century, the integrated disaster risk manage-

ment, risk management requires also a multi-disciplinary approach [5, 7, 10].

ment (IDRIM) is a necessary and required perspective in dealing with disaster risk.

Earthquake culture is particularly linked to earthquake hazard, earthquake risk, and earthquake disasters and refers to the capacities of communities and society of knowing to live with earthquake risk. Seismic culture, local seismic culture, seismic prevention cultures are examples of other interchangeable terms with the earthquake culture. The earthquake culture concept has roots in theoretical insights and research studies carried out during the time in

Mileti and Darlington [20] analyzed the existence of an earthquake culture in the San Francisco Bay Area, years after the Loma Prieta 1989 earthquake. Earthquakes were not frequent in that specific area, but earthquake risk was known and local culture was abundant of accounts of the last and previous other earthquake disasters. Earthquake preparedness and readiness was seen as a part of local culture. Helly [21] emphasized that origins and development of local seismic cultures are influenced by frequency of earthquakes, their intensities, death toll and injuries, and extent of damages. Ferrigni [22] highlighted that a visible cultural adaptation to earthquakes is the seismic architecture or vernacular seismic architecture which develops over the time. However, Ferrigni [22] advised that earthquakes do not always generate a local seismic culture, particularly connected to earthquake resistant buildings. Nevertheless, according to Pierotti [23], the seismic culture can develop during the time, and the case of Japan is given as an example. In Japan, the memory of earthquake disasters has been kept alive through written records, oral accounts, legends, stories, through the lessons from earthquake disasters. Homan ([24], pp. 1–2) employed the hypothesis launched by the European

**5. State of the art on the earthquake culture**

different geographical places around the world.