http://www.seipub.org/updr/paperInfo.aspx?ID=6465 Devastating earthquakes in Iran as an earthquake prone country have often resulted in enormous environmental, economical and cultural heritage damage, loss of life and threats to health. Experiences from the past disasters put a great emphasis on relief and rescue operations. Yazd is an ancient city in Iran which has several historical districts with a very old fabric that’s absolutely unsafe against earthquakes. Fahadan district is the oldest and the most significant district in Yazd city with unique urban texture and famous historical buildings. In this paper it has been attempted to determine and prioritize the most important factors influencing rescue operations in old regions such as Fahadan district. Distance to rescue centers, roads width, distance to open areas, buildings quality, population density and buildings age were determined as the research criteria. Geographic information systems (GIS) and analytic hierarchy pro
www.seipub.org/updr Urban Planning and Design Research (UPDR) Volume 1 Issue 3, September 2013 50 Evaluation of Relief and Rescue Operations in Historic Regions (Case of Study: Fahadan District in Yazd City, Iran) Sina Saeedy *1 , Ali Akbar Shamsipour 2 , Saeed Fallah 3 , Saba Saeedy 4 1- Faculty of Management, University of Tehran, Tehran, Iran 2- Faculty of Geography, University of Tehran, Tehran, Iran 3- Faculty of Environment, University of Tehran, Tehran, Iran 4- Faculty of Management, University of Tehran, Tehran, Iran * [email protected] (Corresponding Author) Abstract Devastating earthquakes in Iran as an earthquake prone country have often resulted in enormous environmental, economical and cultural heritage damage, loss of life and threats to health. Experiences from the past disasters put a great emphasis on relief and rescue operations. Yazd is an ancient city in Iran which has several historical districts with a very old fabric that’s absolutely unsafe against earthquakes. Fahadan district is the oldest and the most significant district in Yazd city with unique urban texture and famous historical buildings. In this paper it has been attempted to determine and prioritize the most important factors influencing rescue operations in old regions such as Fahadan district. Distance to rescue centers, roads width, distance to open areas, buildings quality, population density and buildings age were determined as the research criteria. Geographic information systems (GIS) and analytic hierarchy process (AHP) have been combined to evaluate the capability of rescue operations in the district and to illustrate its most difficult locations to perform relief and rescue services. Finally some approaches as retrofitting and rehabilitation of the old buildings, destroying the abandoned buildings, distributing first aid kits among the local residents, training citizens and performing earthquake maneuvers were suggested to enhance the safety of Fahadan district and to improve the rescue operations capability. Keywords Relief and Rescue; Historic Region; GIS; AHP Introduction Iran is one of the most seismically active regions along the Alpine-Himalayan belts with numerous destructive earthquakes recorded both historically and instrumentally. For example, an earthquake on the 26th December 2003, with a moment magnitude (Mw) of 6.5, resulted in the loss of over 30,000 lives and almost totally reduced the ancient city of Bam and surrounding villages to ruins (Ahmadizadeh and Walker, 2007). Reports show the occurrence of a major earthquake every 2-3 years in Iran. Only in the 20th century, 20 major earthquakes claimed more than 140,000 lives, destroyed several villages and cities and caused extensive economic damages to Iran (UN Flash Appeal, 2004). As shown in FIG. 1 the global seismic hazard map illustrates Iran as a one of the most seismic hazardous countries (USGS, 2012). FIG. 1 GLOBAL SEISMIC HAZARD MAP During the 20th century, more than 1,100 strong earthquakes have occurred, causing more than 1,500,000 casualties. Most of them are due to buildings collapsing, which is some 90% of direct deaths. Advances in structural design were applied to new structures and, to a lesser extent, to the rehabilitation of existing structures. Nevertheless, there are many more old structures than newly constructed ones (Lantada et al., 2009). Many Iranian cities are susceptible to earthquake
Transcript
www.seipub.org/updr Urban Planning and Design Research (UPDR) Volume 1 Issue 3, September 2013
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Evaluation of Relief and Rescue Operations in Historic Regions (Case of Study: Fahadan District in Yazd City, Iran) Sina Saeedy *1, Ali Akbar Shamsipour 2, Saeed Fallah 3, Saba Saeedy 4
1- Faculty of Management, University of Tehran, Tehran, Iran 2- Faculty of Geography, University of Tehran, Tehran, Iran 3- Faculty of Environment, University of Tehran, Tehran, Iran 4- Faculty of Management, University of Tehran, Tehran, Iran *[email protected] (Corresponding Author)
Abstract
Devastating earthquakes in Iran as an earthquake prone country have often resulted in enormous environmental, economical and cultural heritage damage, loss of life and threats to health. Experiences from the past disasters put a great emphasis on relief and rescue operations.
Yazd is an ancient city in Iran which has several historical districts with a very old fabric that’s absolutely unsafe against earthquakes. Fahadan district is the oldest and the most significant district in Yazd city with unique urban texture and famous historical buildings.
In this paper it has been attempted to determine and prioritize the most important factors influencing rescue operations in old regions such as Fahadan district. Distance to rescue centers, roads width, distance to open areas, buildings quality, population density and buildings age were determined as the research criteria. Geographic information systems (GIS) and analytic hierarchy process (AHP) have been combined to evaluate the capability of rescue operations in the district and to illustrate its most difficult locations to perform relief and rescue services.
Finally some approaches as retrofitting and rehabilitation of the old buildings, destroying the abandoned buildings, distributing first aid kits among the local residents, training citizens and performing earthquake maneuvers were suggested to enhance the safety of Fahadan district and to improve the rescue operations capability.
Keywords
Relief and Rescue; Historic Region; GIS; AHP
Introduction
Iran is one of the most seismically active regions along the Alpine-Himalayan belts with numerous destructive earthquakes recorded both historically and instrumentally. For example, an earthquake on the
26th December 2003, with a moment magnitude (Mw) of 6.5, resulted in the loss of over 30,000 lives and almost totally reduced the ancient city of Bam and surrounding villages to ruins (Ahmadizadeh and Walker, 2007).
Reports show the occurrence of a major earthquake every 2-3 years in Iran. Only in the 20th century, 20 major earthquakes claimed more than 140,000 lives, destroyed several villages and cities and caused extensive economic damages to Iran (UN Flash Appeal, 2004).
As shown in FIG. 1 the global seismic hazard map illustrates Iran as a one of the most seismic hazardous countries (USGS, 2012).
FIG. 1 GLOBAL SEISMIC HAZARD MAP
During the 20th century, more than 1,100 strong earthquakes have occurred, causing more than 1,500,000 casualties. Most of them are due to buildings collapsing, which is some 90% of direct deaths. Advances in structural design were applied to new structures and, to a lesser extent, to the rehabilitation of existing structures. Nevertheless, there are many more old structures than newly constructed ones (Lantada et al., 2009).
Many Iranian cities are susceptible to earthquake
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hazard due to their geologic settings .Historic records show many Iranian cities have been suffering from earthquake shocks, leaving many lives and economic looses. Among the cities of Iran, Yazd city has lots of old fabrics which are not safe enough against earthquakes.
TABLE 1 shows the magnitudes and the distances of the earthquakes that have occurred near Yazd city since 1973. According to the table below in the previous four decades, 18 earthquakes greater than 4 on Richter scale have occurred near Yazd city (USGS, 2012).
After the destructive earthquake in Bam city, relief and rescue operation in old cities and regions is considered more important and necessary in Iran.
Experience with emergency management following major earthquakes shows that approximately the first three days after an earthquake event, are essential for the performance of the relief efforts. Afterwards the probability for rescuing trapped people alive, decreases radically. With regard to the overall goal, namely reducing loss of life during this initial SAR (search and rescue) period, the quality of the relief efforts can be improved by an effective use of the available resources. Improvement can be made by using computer-based decision-support systems (Fiedrich et al., 2000).
In this paper it has been attempted to give a brief introduction of Yazd city and Fahadan district, also it has been tried to determine the most influential factors affecting rescue operations while occurring disasters
such as earthquake and fire. A combination of GIS and AHP methods and software tools has been made to evaluate the rescue operation capability of the region, in order to find the most difficult areas to give rescue services, to improve the efficiency of such services.
Study Area
Yazd is a very ancient city in the middle of the desert, in Central Iran. It's one of the oldest living cities of the world where due to specific geographic conditions the old fabric is mostly built with adobe and the mixture of mud and straw.
The old fabric of Yazd consists of many districts such as Fahadan district as one of the oldest ones. This district with a unique uniform texture and famous historical buildings plays a special role in the tourism industry of the city. FIG. 2 shows an aerial view of Fahadan district in Yazd city.
FIG. 2 AERIAL VIEW OF FAHADAN DISTRICT
Research Method
In this research the capability of relief and rescue in the historical region of Fahadan has been evaluated using geographic information systems (GIS) as a powerful tool of geographical data analysis. During the last few years, GIS has been used as a system for management, manipulation, representation and analysis of geospatial data (Vahidnia et al., 2009). In order to analyze such data ArcGis 10 software has been employed.
In order to measure the effects of different influential factors in the capability of relief and rescue, while occurring earthquakes, analytic hierarchy process (AHP) method has been used. This method has been proposed by Thomas L. Saaty (1980) as a tool which can be used in making decisions that are complex,
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unstructured and contain multiple attributes (Nataraj, 2005).
AHP as a multi criteria decision making technique has been repeatedly combined with GIS to provide a powerful visual decision-support for rational land use mapping (Tudes and Yigiter, 2010).
This process has three broad steps:
1- Description of a complex decision problem as a hierarchy.
2- Prioritization procedure.
3- Calculation of results.
AHP is a method of breaking down a complex, unstructured situation into its components parts, arranging these parts or judgments on the relative importance of each variable and synthesizing the judgments to determine which variables have the highest priority and should be acted upon to influence the outcome of the situation.
After consulting with several specialists in the field of relief and rescue and also in disaster management, the most important spatial factors related to rescue operation in earthquake were determined. Then the AHP questionnaires were designed based on these factors and sub-factors and were distributed among several experts. In order to analyze the data of questionnaires Expert Choice 11 software was employed to calculate the results.
Results
In the first step the most important criteria and sub-criteria affecting the rescue operation in the earthquake were determined. These factors are illustrated in FIG. 3 as a hierarchy tree, where the main criteria involve as 1- rescue centers distance, 2- roads width, 3- open areas distance, 4- Buildings structure, 5- Population density and 6- Buildings age, each of which has three sub-criteria that are shown in the hierarchy tree. Relief & Rescue
capability
Centers distance Roads width Buildings structure
Population density
Buildings age Open areas distance
< 20
0 m
200
m –
500
m
> 50
0 m
< 6
m
6 m
– 1
2 m
> 12
m
< 50
m
50 m
– 1
00 m
> 10
0 m
adob
e &
mud
bric
ks &
stee
l
steel
or c
oncr
ete
< 50
0 p/
hec
500
– 10
00
> 10
00
< 20
yea
rs
20 –
60
year
s
> 60
yea
rs
FIG. 3 AHP TREE OF FACTORS
In the second step the pair-wise comparison matrix was constructed as demonstrated in TABLE 2, while TABLE 3 shows the interpretation of the values of the pair-wise matrix (Sener et al., 2010).
TABLE 2 COMPARISON MATRIX
Factors
Centers
distance
Roads
width
Open areas distan
ce
Building
structure
Population
density
Buildings age
Centers distanc
e 1 3 5 6 7 9
Roads width
0.333 1 4 5 6 8
Open areas
distance
0.2 0.25 1 2 3 7
Building
structure
0.166 0.2 0.5 1 2 4
Population
density 0.142
0.166
0.333 0.5 1 5
Buildings age
0.111 0.12
5 0.142 0.25 0.2 1
TABLE 3 INTERPRETATION OF THE VALUES OF PAIR-WISE MATRIX
Values Interpretation 1 equal value 3 slightly higher 5 strongly higher 7 very strongly higher 9 absolutely higher
2, 4, 6, 8 intermediate scales between two adjacent judgments
In the last step the calculations were made using Expert Choice 10 software. FIG. 4 shows the results of AHP calculations which are indeed the weights assigned to each criterion, based on the values in the comparison matrix.
FIG. 4 AHP CALCULATION RESULTS
The overall inconsistency is equal to 0.07 which is less than 10% and approves that the judgments are acceptable.
Such calculations were made for each criterion separately, in order to determine the weights of each criterion’s sub-criteria which are demonstrated in TABLE 4.
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TABLE 4 WEIGHTS OF THE SUB-CRITERIA
Criterion 1 2 3 4 5 6
Sub-criteria
1 0.06 0.72 0.09 0.73 0.1 0.06
2 0.19 0.22 0.22 0.22 0.26 0.21
3 0.75 0.06 0.69 0.05 0.64 0.73
Calculating all the weights, they were assigned to different layers of geographical data in ArcGis 10 software using Analysis Tools, Conversion Tools and Spatial Analyst Tools.
After buffering around each related feature and selecting the specific area according to the sub-criteria in the vector layers and assigning the calculated weights (shown in TABLE 4), the data were converted into raster layers for further calculations. FIG.s 5, 6, 7, 8, 9 and 10 show Fahadan district where according to each main criterion, the areas suitable, moderate and difficult to perform rescue operations have been shown with green, yellow and red colors. In fact the difficulty of rescue operations in the district has been illustrated based on the main criteria.
FIG. 5 DIFFICULTY OF RESCUE BASED ON DISTANCE FROM
RESCUE CENTERS
FIG. 6 DIFFICULTY OF RESCUE BASED ON ROADS WIDTH
FIG. 7 DIFFICULTY OF RESCUE BASED ON DISTANCE FROM
OPEN AREAS
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FIG. 8 DIFFICULTY OF RESCUE BASED ON BUILDING
STRUCTURE
FIG. 9 DIFFICULTY OF RESCUE BASED ON POPULATION
DENSITY
FIG. 10 DIFFICULTY OF RESCUE BASED ON BUILDINGS AGE
Hence the raster calculation was made, assigning each main criterion’s weight and overlaying the entire six layers. FIG. 11 illustrates Fahhadan district based on the final results.
FIG. 11 OVERALL DIFFICULTY OF RESCUE OPERATIONS
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Discussion
Consulting with specialists in the field of relief and rescue and also in disaster management the most effective factors in the rescue operation were categorized and prioritized with AHP method as 1- rescue centers distance, 2- roads width, 3- open areas distance, 4- Buildings structure, 5- Population density and 6- Buildings age, each of which has three sub-criteria that are shown in FIG. 3.
In disasters the seriously injured have to be transported to a nearby hospital as soon as possible, for deaths may occur due to delayed transport (Fiedrich et al., 2000).
There are two rescue centers in Fahadan district including a hospital and a fire station, hence the southern part of the district being far from these two centers, is vulnerable to disasters as demonstrated in FIG. 5.
After the earthquake some roads might be blocked and it is impossible and unsafe for the rescue team to go to the most devastated areas (Zhulin and Yan, 2010).
One of the most important factors that restricts the rescue operations in this district is the width of avenues and alleys that makes some places inaccessible in the earthquake, as shown in FIG. 6. A great part of the district suffers from inadequate roads width. FIG. 12 shows a narrow alley in Fahadan district.
FIG. 12 A NARROW ALLEY IN FAHADAN DISTRICT
Another important factor is proximity to open areas in order to temporarily shelter and treat the injured by the rescue team. Wastelands, parks and school yards were regarded as proper places to be used for such purposes. But as shown in FIG. 7 almost all the district
lacks enough open areas for the rescue operations while occurring a disaster.
Careful site selection is essential for efficient and effective emergency shelters that form a part of post-disaster reconstruction efforts. Emergency shelters are usually established as disaster- prevention facilities in densely populated urban areas in developed countries, but limited numbers of temporary emergency shelters have been established in major cities in most developing countries (Liu et al., 2011).
People who live near open areas require education regarding how to use such areas as safe sites in the case that they live far from established shelters, since for the first days after a disaster the only safe places are temporary shelters and open grounds available.
The amount of destruction is in direct relation with the quality of the structure of buildings, while mud-brick buildings have the least tolerance of seismic waves (Tahmasebi et al., 2005).
Hence the quality of buildings structure is also a serious problem in the old fabric such as Fahadan district. Most buildings in this district are made of adobe and the mixture of mud and straw which are not safe against earthquake moreover collapse of such buildings results in a large amount of bebris which impedes the rescue operation. As shown in FIG. 8 a large number of buildings are extremely vulnerable to disaster due to weak structures.
Expected casualties in an urban area are strongly correlated not only with the severity of the hazard but also with the density of population (Lantada et al., 2009).
Hence the population density is a significant item intensifying the rescue operation. According to FIG. 9 approximately most parts of the district are not crowded but the population density in some certain parts is very high. In order to decrease the hazard risks this population should be distributed into other areas.
The construction quality in Iran is generally poor, particularly in small towns and villages. The buildings in these regions are highly vulnerable even to moderate earthquakes and most of them completely collapse when subjected to these excitations (Ahmadizadeh and Shakib, 2004).
The age of buildings can represent their construction quality. Since a large number of buildings in Fahadan district are older than 60 years, many parts of the
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district are extremely vulnerable to disasters which are shown in FIG. 10.
FIG. 11 depicts the combination of all factors together after assigning the calculated weights and overlaying the layers. This final map obviously demonstrates that specific parts of the district, which are difficult to perform rescue operations.
Conclusions
In this research the capability of rescue operations in Fahadan district of Yazd city in Iran was evaluated using GIS and AHP methods. The most significant factors influencing relief and rescue were determined and prioritized as 1- rescue centers distance, 2- roads width, 3- open areas distance, 4- Buildings structure, 5- Population density and 6- Buildings age.
In order to increase the capability of the district to perform relief and rescue, abandoned buildings should be destroyed. Therefore, by developing more open areas there will be more areas for temporary sheltering and also more landing zones for medical helicopters.
Widening the narrow avenues and alleys is another necessary action which can enhance the capability of rescue operations.
As the most buildings’ structures are very old and unsafe in Fahadan district, retrofitting and rehabilitation of the buildings can decrease the damage caused by possible disasters particularly in the most vulnerable parts of the district shown in FIG. 11.
Training the local residents of this district and performing earthquake maneuvers are suggested because of the high vulnerability of this part of the city.
Also it’s suggested to distribute first aid kits and fire extinguishers among the citizens, in addition providing check lists of first aid equipments for each building can be helpful while facing a disaster.
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Sina Saeedy, is an MSc of Urban Management from the Faculty of Management, University of Tehran, Tehran, Iran.
