CHAPTER 1 - INTRODUCTION
1
CHAPTER 1 - INTRODUCTION
A natural disaster is generated by an extreme phenomenon of nature that threatens human lives,
activities or property, or the landscape; in other words the entire anthropic environment.
However, the natural phenomena are not natural disasters by themselves, but they could become
when the place afflicted is highly vulnerable or exposed. Almost always, the disasters are not
caused by the hazards but by the “predisposition” of the human communities to be afflicted: the
vulnerability. For instance, if two major earthquakes, with same characteristics and magnitude,
happen, one in a desert and one in the middle of a settlement, the first one, having no direct
consequences on human life, will be considered a natural phenomenon and maybe only the
geologist will notice it, while the second one, probably causing many casualties and damages,
will be considered a natural disaster, and it has to be faced by the whole community.
In the last century, the number of natural catastrophes reported vastly increased. Only in 2011,
according to the EM-DAT
1
database, there were more than 302 natural disasters all around the
world, costing over 29,780 lives and affecting
2
nearly 206 million others. As Smith (2001) says,
“about 25 percent of the world’s population live in areas at risk from natural disasters”, and
every year this percentage is increasing. According to Alexander (2010), “the relentless rise in
global population, polarization of wealth between rich and poor, marginalization of vulnerable
communities, [..] have all contributed to the increasing toll of natural disasters”. All over the
world, to meet the insatiable demand for land, communities were built in the more dangerous
areas, more prone to natural disasters; those places were systematically spared (or at least only
the places at risks different than the geological; see Paragraph 2.1) by the historic settlements
which, for obvious reasons, were built in more safe areas.
This increased demand for land is first of all due to the world population’s growth (Table 1.1
show that today, in 2010, the world population is more than four times in confront of the
beginning of the last century), in parallel with the growth of the urban population, which in
2010, for the first time in history, exceeded the rural population (see Table 1.2). Each day,
according to Guha-Sapir et al. (2011), “almost 180,000 people move to cities. While city
populations grow faster than city infrastructure can adapt, migrants often encounter a lack of
infrastructure, services, housing and property rights. These urban newcomers are forced to live
in unsafe [and often informal] places”.
However, formal planning has also made some mistakes. Indeed, it often stoops to compromises
1
It is a worldwide database on disasters which is maintained by the Centre for Research on the
Epidemiology of Disasters (CRED) of The Catholic University of Louvain in Brussels-Belgium and by
the United States Agency for International Development’s Office of Foreign Disaster Assistance
(USAID/OFDA).
2
With “affected” it’s meaning the number of people requiring immediate assistance during a period of
emergency; so, this may include displaced or evacuated people.
CHAPTER 1 - INTRODUCTION
2
and allows new construction permissions in areas that are not safe. New settlements and
infrastructures are being built on active faults, under landslides or mudslides, in flooding areas,
in areas of volcanic eruptions, etc. Unfortunately, this trend is not only typical of poor and
developing countries but also of the most rich and developed ones.
Therefore, the number of elements under risk, the casualties and the damages, has increased and
it is likely that they will increase further in the future.
Table 1.1. Evolution of the World population
(* DESA, 1999; ** DESA, 2011)
Year World population Source
0 300.000.000 *
1000 310.000.000 *
1250 400.000.000 *
1500 500.000.000 *
1750 790.000.000 *
1800 980.000.000 *
1850 1.260.000.000 *
1900 1.650.000.000 *
1910 1.750.000.000 *
1920 1.860.000.000 *
1930 2.070.000.000 *
1940 2.300.000.000 *
1950 2.520.000.000 **
1950 2.532.229.000 **
1960 3.038.413.000 **
1970 3.696.186.000 **
1990 5.306.425.000 **
2000 6.122.770.000 **
2010 6.895.889.000 **
CHAPTER 1 - INTRODUCTION
3
Table 1.2. Percentages of urban population since 1950 to 2050
(DESA, 2012)
Year World More developed regions Less developed regions
1950 29,4% 54,5% 17,6%
1955 31,4% 57,7% 19,6%
1960 33,6% 60,9% 21,8%
1965 35,5% 63,9% 24,0%
1970 36,6% 66,6% 25,3%
1975 37,7% 68,7% 27,0%
1980 39,4% 70,1% 29,5%
1985 41,2% 71,3% 32,3%
1990 43,0% 72,3% 34,9%
1995 44,8% 73,2% 37,5%
2000 46,7% 74,1% 40,1%
2005 49,1% 75,9% 43,0%
2010 51,6% 77,5% 46,0%
2015 53,9% 78,8% 48,7%
2020 56,0% 80,0% 51,3%
2025 58,0% 81,1% 53,6%
2030 59,9% 82,1% 55,8%
2035 61,7% 83,1% 57,9%
2040 63,5% 84,1% 60,0%
2045 65,3% 85,0% 62,0%
2050 67,2% 85,9% 64,1%
Among the natural phenomena, earthquakes are probably the most dangerous. Indeed, a seismic
event could strongly shake human settlements in few seconds, causing casualties and injuries
for thousands or hundreds of thousands, devastating and destructing residential buildings,
“health and public safety places” (such as hospitals, police stations, fire stations, etc.) and
erasing the historical-cultural heritage stratified in centuries of history. Then, these direct and
structural effects could trigger other secondary ones of primary gravity, such as disruption of
economic activities and services, social problems, etc. Therefore, an earthquake could be
potentially more dangerous in “global cities”, which are important for their economic-financial
richness, the number of inhabitants, and the number of services provided. Surely, Istanbul is one
of these “global cities” with a one of the highest seismic risks in the world. The economic
capital of Turkey, it is an important attractive node of economic activities, from economic and
financial capitals in Turkey and from the rest of the world. Thus, an estimated earthquake of 7.7
magnitude (in the worst case scenario) could seriously damage the city and, with its direct and
indirect effects, the whole nation. In the light of these observations, this expected seismic event,
CHAPTER 1 - INTRODUCTION
4
a natural phenomenon, will be transformed into a natural disaster for Istanbul and for its
inhabitants, due to the city’s vulnerabilities.
Moreover, inside these “global-cities”, there are always some neighborhoods with particular
vulnerabilities. They could be characterized by a high density of residential population,
economic activities, an important historical and cultural heritage, etc. In Istanbul, there is more
than one area like this. For instance, one is the area around İstiklal Caddesi, famous pedestrian
street which is, according to an unofficial source, visited by nearly 3 million
3
people in a single
day during the weekends. The area is also characterized by an important historical, cultural and
architectonical heritage; it is the location of several economic activities (such as shops,
restaurants, offices) and public facilities (such as hospitals and schools). Hence, it is an area
with a vital and crucial importance, an area which acts as the heart of the city. For this reason,
damages here could be exponentially larger and involve the whole metropolitan context.
Considering the importance of the seismic issue, this master thesis is focused on it. In particular,
after a study of the theoretical scientific literature on the subject, the seismic risk will be
assessed in this urban-metropolitan context, in one of the most vulnerable areas of Istanbul: the
one around İstiklal Caddesi. It is, perhaps, not characterized by a high hazard risk and thus it is
also not deeply studied and not so much an object of mitigation projects as other parts of the
city characterized by a higher seismic hazard, but it is certainly characterized by a major
vulnerability and thus by a high seismic risk.
Firstly, this evaluation will be done using a commonly accepted theoretical method and then
using a new one, which should be more accurate, according to the particular characteristics of
the area in question. This assessment will make possible to understand how to mitigate the
area’s seismic risk with appropriate disasters management policies.
To support this purpose, the author conducted an inspection-survey. Between December 2011
and February 2012, almost 1,200 buildings belonging to the area in question have been
cataloged in a database recording their heights, their urban functions and activities inside, their
general structural quality, any extra-connotative features, etc.
1.1 Hypotheses
According to the above, here some hypotheses are set forth, whose veracity will be verified in
the last chapter, after the analysis is carried out.
1. Neighborhoods characterized by a low seismic hazard might nevertheless have a high
seismic risk
3
This is an unofficial statistic dating back to 2011 and concerning just Istiklal Caddesi (Turkish
Wikipedia, May 2012).
CHAPTER 1 - INTRODUCTION
5
2. The vulnerability of a neighborhood could change during the day and in relation to the
day’s typology (weekday or weekend).
3. The mobility of the population influences and changes the vulnerability of the area and
thus also the seismic risk.
4. The presence of different and several functions could increase or decrease the
vulnerability of the area, and thus also the seismic risk.
5. The structural quality of the buildings, and so the physical vulnerability of an area,
could be increased by the typology of urban functions located inside the buildings
themselves. So buildings with a high resistance-resilience might not be sufficiently safe.
6. The presence of emergency facilities could not exercise their functions in the rescues
operations, even if they are located in highly structurally resistant buildings. Therefore,
their presence does not ensure notwithstanding a strength for the area nearby where they
are located.
7. The socio-demographic vulnerability of the population is not only related to the
physical shape condition of the inhabitants.
1.2 Thesis’ structure
This thesis is developed in four more chapters. In CHAPTER 2 will be discuss the natural
disasters and the risks in general focusing on the seismic risk of earthquakes. In CHAPTER 3, a
framework of Turkey, on the city of Istanbul and on its earthquake history, will be described.
Then, CHAPTER 4 will treat the mean studies on the seismic risk in Istanbul and a new
experimental method will be tested. According to the assessments elaborated in this last one,
finally, in the CHAPTER 5, the emergency planning in Istanbul will be discussed in depth,
some solutions will be proposed and the hypothesis, mentioned here in the introduction chapter,
will be discussed and argued.
CHAPTER 2 - THEORETICAL BACKGROUND
6
CHAPTER 2 - THEORETICAL BACKGROUND
This chapter describes a useful theoretical background necessary to better understand and frame
the project which is developed and illustrated in the following chapters. Thus, according to the
title of this work, it is necessary to discuss natural disasters and risks in general, and then to
focus more closely on earthquakes and seismic risks.
2.1 Natural disasters
According to Smith (2001), “about 25 per cent of the world’s population lives in areas at risk
from natural disasters”. A natural disaster is generated by an extreme phenomenon of nature that
threatens human and natural lives, activities and property, the environment of life, the
landscape. Gencer (2008) notes that “the United Nations International Strategy for Disaster
Reduction Secretariat (UN/ISDR 2004, 2:3) defines disaster as a serious disruption of the
functioning of a community or a society causing widespread human, material economic or
environmental losses which exceed the ability of the affected community or society to cope
using its own resources”. Moreover, Smith (2001) refers that a natural disaster could be defined
“an event, concentrated in time and space, in which a community experiences severe danger and
disruption of its essential functions”.
As Alexander (2008) indicates, “the question of exactly what phenomena should be classified as
natural hazards has long been debated by students of the field”. Again according to Alexander
(2008), “the core phenomena consist of geophysical events from the atmosphere, hydrosphere,
and geosphere (the lithosphere), and to a lesser extent from the biosphere”. As illustrated in the
Figure 2.1, the principal geological hazards are earthquakes, landslides, and subsidence of the
ground. Tropical cyclones (also known as hurricanes and typhoons), tornadoes, and windstorms
are the leading examples of atmospheric hazards, while droughts and floods are the principal are
the principal hydrological threats. These two last categories could be group together under the
“big” meteorological category. Finally there are the biological hazards such as bacterial and
viral infestations.
CHAPTER 2 - THEORETICAL BACKGROUND
7
Tectnocic (internal eatrh
process)
Mass and/or rapid
movements (external
earth process)
Hydrological Atmosferic and severe
storms
Floral Faunal
Earthquakes and fault
activities, volcanic
eruptions, tsunamis
Landslides, rockslides
and falls, avalanches,
surface collapses, soil
debris or mudflows
Floods, debris and
mudfloods, droughts
Blizzards, thunders,
tornadoes and
tropical cyclones
(hurricanes,
typhoons), extreme
temperatures
Fungal diseases and
infestations
Bacterial, viral and
protozoal diseases,
infestations
Geological Metereological Biological
NATURAL DISASTERS
Figure 2.1. The typology of natural disasters
(Gencer, 2007)
CHAPTER 2 - THEORETICAL BACKGROUND
8
Furthermore, natural phenomena could become risky either by excess (too great rainfall may
cause flood) or by dearth (too little rainfall could cause drought). According to the International
Encyclopedia of the Social Sciences (2008), “a situation becomes hazardous when the physical
forces or environmental stresses at work exceed the ability of human social, economic, cultural,
or health systems to absorb, resist, or avoid the resulting negative impact. In this respect, natural
hazards are defined not only by the natural forces that induce them, but also by the vulnerability
of human systems. Vulnerability is defined here as the susceptibility of people or things to
harm”.
As stated once again by the International Encyclopedia of the Social Sciences (2008), “many
hazards are cyclical; for example, earthquakes of a certain size will occur on a given fault when
enough tectonic stress has been accumulated to overcome the frictional resistance of the rock
mass to slipping, a process which will probably occur with a definable time interval because of
the gradual build-up of strain on the fault. Other hazards, especially meteorological ones, may
be seasonal”.
Figure 2.2 shows that the number of natural disasters reported have vastly increased in the
second half of the last century. According to Alexander (2010), “the relentless rise in global
population, polarization of wealth between rich and poor, marginalization of vulnerable
communities, and the prevalence of about twenty-five complex humanitarian emergencies have
all contributed to the increasing toll of natural disasters. So has the increasing complexity and
interdependence of modern society, and so, no doubt, will global warming and climate change,
as more extreme, if not more frequent, meteorological phenomena are likely to occur”.
CHAPTER 2 - THEORETICAL BACKGROUND
9
Figure 2.2. Natural disasters reported between 1900 and 2010
(EM-DAT, 2011)
Looking to the Table 2.1, it is possible to see how earthquakes are the most devastating among
natural disasters in terms of the people killed (or rather the number of people confirmed dead
and the number of missing and presumed dead). In the ranking of the world’s greatest natural
disasters since 1900, nine out of ten are earthquakes. The list of top ten disasters ranked by
estimated damage (global figures of the economic impact of a disaster) is likewise dominated by
earthquakes (Table 2.2).
CHAPTER 2 - THEORETICAL BACKGROUND
10
Table 2.1. The top 10 natural disasters in the world between 1900 and2011 according to death tolls
(EM-DAT, 2012)
Natural disaster typology Country Date No. Killed
Earthquake People's Republic of China 27/07/1976 242.000
Earthquake Haiti 12/01/2010 222.570
Earthquake People's Republic of China 22/05/1927 200.000
Earthquake People's Republic of China 16/12/1920 180.000
Tsunami Indonesia 26/12/2004 165.708
Earthquake Japan 01/09/1923 143.000
Earthquake Soviet Union 05/10/1948 110.000
Earthquake People's Republic of China 12/05/2008 87.476
Earthquake Italy 28/12/1908 75.000
Earthquake Pakistan 08/10/2005 73.338
Table 2.2. The top 10 natural disasters in the world between 1900 and 2011 according to damage costs
(EM-DAT, 2012)
Natural disaster typology Country Date Damage in 1,000 US$
Earthquake and tsunami Japan 11/03/2011 210.000.000
Earthquake Japan 17/01/1995 100.000.000
Earthquake People's Republic of China 12/05/2008 85.000.000
Earthquake United States 17/01/1994 30.000.000
Earthquake Chile 27/02/2010 30.000.000
Earthquake Japan 23/10/2004 28.000.000
Earthquake Italy 23/11/1980 20.000.000
Earthquake Turkey 17/08/1999 20.000.000
Earthquake Taiwan (China) 21/09/1999 14.100.000
Earthquake Soviet Union 07/12/1988 14.000.000
Figure 2.3 and the Figure 2.4 show how the trend is improving in terms of the people killed.
Indeed, both the average trend and the single-year trend clearly lower in the last forty years.
Instead, considering the estimated damages during the last 110 years, the trend is the opposite.
Figure 2.5 shows that the estimated damage caused by disasters has increased during the last
three decades; the worst damage has been caused by earthquakes, except for Hurricane Katrina
in 2005.
CHAPTER 2 - THEORETICAL BACKGROUND
11
Figure 2.3. Number of people reported killed by natural disasters between 1900 and 2010
(EM-DAT, 2011)
Figure 2.4. Number of people reported killed by natural disasters between 1975 and 2010
(EM-DAT, 2012)
CHAPTER 2 - THEORETICAL BACKGROUND
12
Figure 2.5. Annual reported economic damage from disasters between 1980 and 2011
(CRED 2012)
CHAPTER 2 - THEORETICAL BACKGROUND
13
These opposing trends can be easily understood. On one hand, the countries severely affected by
natural disasters – particularly the more developed ones – have established efficient and
organized civil protection systems in the last half-century. In many countries rescue operations
now begin in the hours immediately after the occurrence of a natural disaster, thus significantly
reducing the number of victims of such events as earthquakes. Indeed, in many cases more than
half of the victims die under the rubble because of the delays in rescue efforts. Furthermore, an
excellent forecasting and warning system was developed. Especially in the case of floods or
extreme weather events, it is now possible to predict the occurrence of natural hazards with
reasonable precision in advance, and so warn and secure the populations affected. Moreover, the
improvement of anti-seismic building techniques has considerably reduced the number of
buildings collapse during an earthquake. For this reason, almost all of the countries affected by
earthquakes have instituted anti-seismic building codes.
In contrast, the growing number of natural disasters reported (see Figure 2.2) has caused an
associated increase in estimated damage; the growth of towns, cities and infrastructures has also
increased the material damage caused by natural disasters. This trend is occurring not only in
rich countries but all over the world. In addition, to meet this insatiable demand for land due to
first of all to the growth of the world population (which is now at least four times what it was at
the beginning of the last century), settlements were built in the most dangerous and natural-
disaster-prone areas. Those places were systematically spared by the historic settlements which,
for obvious reasons, were built in more safe areas
4
. Indeed, an increasing number of buildings
and infrastructure are being built on active faults, subject to landslides and mudslides, in flood
plains, close to volcanoes, etc. Therefore, the number of elements under risk is increasing. For
these reasons, the damage caused by a natural hazard tend to increase, and it is likely that it will
continue to do so in the future.
According to EM-DAT
5
database, more than 302 natural disasters occurred all around the world
in 2011, claiming 29,780 lives and affecting
6
nearly 206 million others (see Table 2.3).
Table 2.3 and Figure 2.6 show that the occurrence and impact on communities of disasters in
4
This statement does not refer to the natural disasters originated by Tectonic phenomena. For instance, in
the past the earthquakes were not known as results of natural dynamics and people thought there causes
were mystic and related to the goodness will. Moreover, the occurrence of the geological events is more
spread in the time and not cyclic as other phenomena (i.e. floods due to seasonal rains) and thus in the
past they were not well reordered and remembered. Therefore, surely some settlements were built in areas
prone to the seismic hazard: Istanbul is a good example.
5
The EM-DAT is a worldwide database on disasters which is maintained by the Centre for Research on
the Epidemiology of Disasters (CRED) of the Catholic University of Louvain in Brussels, Belgium, and
by the United States Agency for International Development’s Office of Foreign Disaster Assistance
(USAID/OFDA).
6
With “affected” it’s meaning the number of people requiring immediate assistance during a period of
emergency; so, this may include displaced or evacuated people.
Ricevi informazioni sui nostri servizi, sulle offerte e non perdere news e consigli su università e lavoro.
