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Showing 9 results for Natural Hazard
Mehdi Ramezanzadeh Lasboei, Ali Asgari, Seyed Ali Badri,
Volume 1, Issue 1 (4-2014)
Volume 1, Issue 1 (4-2014)
Abstract
Natural disasters are investigated of various dimensions and consequences of natural hazards. As well, they can become as a repeatable phenomenon in the absence of mitigation systems, and could be caused devastating consequences. Resiliency approach as a basis for reducing the negative effects is taken into account to reduce the impact of natural disasters. Today, the two tourist areas of Cheshmekile (Tonkabon County) and Sardabrud (Kelardasht County) as typical feature of regional tourism planning have important potentials for development of tourism. But in recent years they have repeatedly been invaded by floods so that in some cases the impact of economic, environmental, socio-cultural and physical environment is followed. In economic dimension, flash flood destroyed agricultural fields and rural houses and in socio-cultural dimension it has increased insecurity. And finally, in terms of the physical and environmental aspect, it has created the most damage such as adverse changes in the appearance of the landscape, loss of trees, and destruction of public infrastructure (roads and bridges network). It is an approved hypothesis that rural settlements cannot be moved to the riverbank, but have created a situation that endangered abiding rural settlement. Various aspects such as socio-cultural, economic and administrative highly effect on resiliency. Among them, the role of infrastructures such networks, the location of health care facilities, police stations, fire stations and disaster management offices, communication networks (telephone, Internet) are more important to improve resiliency. This paper seeks to answer the key question that is the infrastructure in promoting resiliency after flooding in the two areas satisfactory? The methodology of the study is objective and analytical analysis is based on the nature and method. The main variables are infrastructures and resiliency. Resiliency as the dependent variable consists of two main components of individual and community resiliency. Required information on the objectives, data integrity and availability has been developed in both library and field methods. In previous studies, library and documentation center is studied. Questions are sorted in the distance range, rated and ranked based on the needs and nature of the research and the knowledge and the education level of the local community. Questions are tested initially and after a measurement of the level of reliability (0.812), which is obtained using Cronbach's alpha. First, to determine the total sample size of villages located in flood risk areas in the two basins 9 villages (50%) were selected. Cochran formula is used to determine sample size. According to Cochran formula for the total population 296 households that included 129 head of households for Sardabrud basin and 167 head of households for Cheshmekileh basin. After the initial survey the collected information is encoded using a statistical software SPSS and then has been processed according to the assumptions formulated. Based on the results of the questionnaire analysis, some indicators, same as access to aid agencies (Crescent) and disaster management center, there were no significant differences between rural settlements such as the two basins distance to the city center is short. The nearest major communication route roads - Branch is located at a distance of 5 km from the city of Kelardasht, but in Cheshmekileh basin there are less than 5 kilometers distance to the main road of the Caspian Sea. That is why the average satisfaction of the local authorities in these areas is much higher than Sardabrood basin. Check out the highlights of each area residents is showed more satisfaction on facilities and services infrastructure in Cheshmekile. Result. To understand the relationship between resiliency and infrastructure used is the correlation coefficient between these two measures 003/0 there is level. This relationship of mutual relations, the improvement of infrastructure in the area with 99% probability of increasing population resiliency against natural disasters (floods) within it. The average calculated for the physical aspects - infrastructure represents the position of the component. Ring roads in northern cities, near airports such as Ramsar Branch, and there are several large medical centers, access to police stations in both basins are made from the perspective of the respondents favored the status of this criterion is to be evaluated. However, among the subset of infrastructure, the roads are better than others. The reason can be attributed to the investment and construction of new networks of communication. In the case of energy network, although the topography of the area is caused that part of the basin, some of villages such as Gavpol, Letak, Drazlat in Cheshmekile basin and Lush, Krdychal and Roudbarak in Sardabrood basin was still stay deprived of the gas network but have favorable drink water and electricity network. However, keeping the population in the rural area is largely dependent on the infrastructure. Resiliency in relation to rural and infrastructural facilities, access to places of temporary accommodation is very important but in this particular field in any of the villages still planning has been done.
Seyed Reza Azadeh, Masood Taghvaei,
Volume 4, Issue 3 (9-2017)
Volume 4, Issue 3 (9-2017)
Abstract
The field of natural hazards research has a rich history in geography, appropriately so because it involves conflicts between physical processes and human systems. Natural events occur without direct human effect and endanger his social life. Events that enforce average annual up to 150000 human damages and more than 140 milliard dollars financial damages on counties and especially developing countries. Among all the natural disasters, the earthquake is one of the most serious ones. It brings tremendous economic losses and deaths of people, as well as the enormous effects on the harmonious and continuous development of society. Iran is an event ism country in the world. In this field look at the recent decades earthquakes statistics that reveal average once in every five years.
Gilan province is located in south western of Caspian Sea in mountainous area of Talesh and central Alborz range that endure many earthquakes up today. The most ancient earthquake ever occurred in this area refers to Marlik civilization which is located near Rudbar – Rostam Abad. One of the recent earthquake in the 20th century in this area is Rudbar earthquake in 21 Jun 1990 with magnitude Ms = 7.7 Richter that caused many destruction. In one hand according to complex tectonic of central Alborz and in the other hand locating Gilan in the south west of Caspian sea that demonstrate many seismic activities, it illustrates as a result that this area is one of the active high potential seismic area of Iran.
The current study is aimed at investigating the earthquake vulnerability of rural and urban settlements of Gilan province. To this end, Euclidean distant analysis and raster overlay have been conducted in GIS. To run the procedure, the first step is to calculate distance (pixels in 86 m dimension) between province and active and inactive fault line based on Euclidean analysis distance in Arc Map. The next step is aimed at standardizing the calculated distances using Raster Calculator Command. The, zoning of earthquake vulnerability of Gilan into five zones (based on active/inactive faults) is the primary goal. As a matter of fact, standardization leads to fuzzy maps. Standard score (distance) is calculated by dividing each score by sum of the scores. The next step tries to categorize zoning map and to translate Raster map into vector one in order to calculate the area of each risk category. Finally, overlay of urban and rural layers base on zoning map may help us analyze seismic hazard urban and rural regions of Gilan province.
Results have shown that 40.72 % of total area of Gilan province are in 15 km distance from active fault. Also, 21.51 % of total area of Gilan province are in 15 to 30 km distance from active fault. Additionally, 64.45 % of total area of Gilan province are in less than 8 km distance from inactive fault (Table 1).
Table 1. Seismic hazard zonation according to faults
Gilan province is located in south western of Caspian Sea in mountainous area of Talesh and central Alborz range that endure many earthquakes up today. The most ancient earthquake ever occurred in this area refers to Marlik civilization which is located near Rudbar – Rostam Abad. One of the recent earthquake in the 20th century in this area is Rudbar earthquake in 21 Jun 1990 with magnitude Ms = 7.7 Richter that caused many destruction. In one hand according to complex tectonic of central Alborz and in the other hand locating Gilan in the south west of Caspian sea that demonstrate many seismic activities, it illustrates as a result that this area is one of the active high potential seismic area of Iran.
The current study is aimed at investigating the earthquake vulnerability of rural and urban settlements of Gilan province. To this end, Euclidean distant analysis and raster overlay have been conducted in GIS. To run the procedure, the first step is to calculate distance (pixels in 86 m dimension) between province and active and inactive fault line based on Euclidean analysis distance in Arc Map. The next step is aimed at standardizing the calculated distances using Raster Calculator Command. The, zoning of earthquake vulnerability of Gilan into five zones (based on active/inactive faults) is the primary goal. As a matter of fact, standardization leads to fuzzy maps. Standard score (distance) is calculated by dividing each score by sum of the scores. The next step tries to categorize zoning map and to translate Raster map into vector one in order to calculate the area of each risk category. Finally, overlay of urban and rural layers base on zoning map may help us analyze seismic hazard urban and rural regions of Gilan province.
Results have shown that 40.72 % of total area of Gilan province are in 15 km distance from active fault. Also, 21.51 % of total area of Gilan province are in 15 to 30 km distance from active fault. Additionally, 64.45 % of total area of Gilan province are in less than 8 km distance from inactive fault (Table 1).
Table 1. Seismic hazard zonation according to faults
| Probability of earthquake hazard | Distance to fault lines | Relative area | |||
| Active Faults | Passive Faults | Active Faults | Passive Faults | ||
| Very low risk | 0-20 | 60-76 | 32-42 | 7.29 | 1.42 |
| Low risk | 20-40 | 45-60 | 24-32 | 13.82 | 3.96 |
| Medium risk | 40-60 | 30-45 | 16-24 | 16.66 | 8.13 |
| High risk | 60-80 | 15-30 | 8-16 | 21.51 | 22.04 |
| Very high risk | 80-100 | 0-15 | 0-8 | 40.72 | 64.45 |
| sum | - | 100 | |||
According to seismic hazards due to active faults, 18 cities out of 51 urban regions are severely vulnerable to earthquake. Accordingly, 67.20 % of Gilan urban population are located at high-risk zone. Seismic hazard zoning map based on active faults have indicated that 20 cities are highly vulnerable to earthquake. (Table 2)
Table 2. Investigating the risk of earthquake in urban areas of Guilan province
| Probability of earthquake hazard | urban Settlement | Population (2011) | Relative population frequency (percent) | ||||
| Active Faults | Passive Faults | Active Faults | Passive Faults | Active Faults | Passive Faults | ||
| Very low risk | 0-20 | 3 | 1 | 135846 | 17106 | 1.14 | 9.07 |
| Low risk | 20-40 | 6 | 4 | 86133 | 144021 | 9.62 | 5.75 |
| Medium risk | 40-60 | 10 | 8 | 739095 | 754968 | 50.43 | 49.37 |
| High risk | 60-80 | 14 | 18 | 380908 | 273137 | 18.24 | 25.44 |
| Very high risk | 80-100 | 18 | 20 | 155188 | 307938 | 20.57 | 10.37 |
| sum | 51 | 1497170 | 100 | ||||
Seismic studies on rural settlement of Gilan province have indicated that 1350 rural out of 2925 rural residences are severely vulnerable to earthquake because they are near to active faults. These regions are the habitat of 24.9 % of the total rural population. Zoning map based on inactive faults have shown that 1679 rural regions are vulnerable to earthquake (Table 3).
Table 3. Probability of earthquake hazard in rural settlements
| Probability of earthquake hazard | Rural Settlement | Population (2011) | Relative population frequency (percent) | ||||
| Active Faults | Passive Faults | Active Faults | Passive Faults | Active Faults | Passive Faults | ||
| Very low risk | 0-20 | 162 | 42 | 54240 | 30236 | 5.51 | 3.07 |
| Low risk | 20-40 | 379 | 147 | 183718 | 92018 | 18.68 | 9.35 |
| Medium risk | 40-60 | 481 | 291 | 255412 | 176183 | 25.96 | 17.91 |
| High risk | 60-80 | 553 | 766 | 245392 | 340448 | 24.95 | 34.61 |
| Very high risk | 80-100 | 1350 | 1679 | 244942 | 344819 | 24.90 | 35.05 |
| sum | 2925 | 983704 | 100 | ||||
Studies have claimed that the majority of rural and urban regions of Gilan province are severely earthquake-prone. It is due to geographic and natural features of the mentioned province. To this end, some recommendations are given:
- Meticulous supervision on safety of building from the stage of plan-making to administration which have to be based on engineering principles for earthquake-prone cities including Baresar, Ataqur, Asalem, Haviq, and Roodbar which are next to active faults
- Prevention of formation of suburbs and towns on southern and northern parts of Gilan because these parts are really vulnerable to earthquake
- Prediction of temporary accommodation in central Gilan because this part is less vulnerable to earthquake
- To equip buildings, hospitals, schools, and other buildings located in big cities including Rasht, Bandar-E Anzali, Fuman, and Lahijan with facilities required in case of earthquake
- To hold training courses in rural and urban parts of the mentioned province to make residents prepared for earthquake and for emergency evacuation
- To prioritize reformation of old and historical buildings in Rasht because Rasht is mostly laden with old buildings which are really vulnerable to earthquake
Farzaneh Sasanpour, Navid Ahangari, Sadegh Hajinejad,
Volume 4, Issue 3 (9-2017)
Volume 4, Issue 3 (9-2017)
Abstract
International studies show that the damages caused by natural hazards is essential that special attention to natural hazards in urban societies of the world, especially in urban areas of developing countries. In many of these communities needed new ways to deal with these challenges. This method should provide sufficient knowledge to identify the nature of problems and the identification of individual characteristics, socio-economic, physical, environmental and management, would in effect do the "Back to Balance" against natural hazards. This feature Back to Balance the same resiliency. The term resilience has a very long history and its use goes back at least a century BC. According to the different interpretations of the concept of resilience, this term is rooted in the traditions of various disciplines such as law, engineering, ecological and social sciences. Today, the concept of resilience has entered the field of planning with different orientations (social, economic, physical, and administrative, etc.).Although it still focuses more attention on environmental issues and a large part of its exploration dedicated to managing the environmental hazards such as earthquakes, floods, hurricanes and global warming. Tehran, as a result of political and economic influence, special conditions to deal with the crisis in terms of the influence of natural disasters and crisis management in terms of organizational structure and legal. In this respect, residential and urban areas of 12 with characteristic their history can be acute against the imbalances caused by natural hazards and create a crisis in urban life. Therefore, the present study has been prepared for the purpose of stability analysis flexibility in District 12 of Tehran metropolitan city.
This is of cognitive research that has been done for analytical and descriptive. All data is obtained in the manner of library and field. The library of available resources and work conducted the form of a questionnaire survey. Questionnaires have been used of type Likert spectrum (numerous, high, high, somewhat, relatively low, low and very low), and its completion is done by fieldwork. Statistical population has problems of urban planning experts, among them 80 people were interviewed for targeted samples. Resiliency that includes four dimensions (economic, social, ecological, environmental and institutional). Was approved the validity of the index by 7 experts manage urban planning problems. For measuring reliability coefficient is calculated Cronbach's alpha equal to 0/79. For data analysis, the use of statistical analysis such as frequency, maximum and minimum, average and standard deviations, T-Test one sample test and Friedman nonparametric test
The results of the indicators of urban resiliency against natural hazards suggests that economic indicators 73/24 Average been determined and relatively low level, ie below the average level. Results of the test showed one sample T-Test is an indicator of economic status of urban resilience against natural hazards of poor utility. As well as the social, ecological, environmental and institutional (organizational) urban resilience against natural hazards associated with poor utility. Finally the 12 metropolitan Tehran metropolitan areautility resilience against natural hazards with respect to all dimensions were too weak. Friedman test results on the scoreboard indicators showed that the index of environmental sustainability (20/33) related to the ecology and environment in the first rank the importance of urban resilience and adaptability Index System (10/11) related to next institutional (organizational) is set as the least significant indicator. Also, significant chi-square statistic is calculated at a rate of 09/67 in three degrees of freedom at the level of 0.000. So, with a probability of 99% can be said that there is a significant difference between the performance rating of 80 specialist urban resilience dimensions (economic, social, ecological, environmental and organizational) against natural hazards, and not the distribution of the same rank.
This research been prepared with the aim of assessing the scale of urban resilience against natural hazards in District 12 of Tehran Metropolis. Results showed that social, environmental and institutional ecology and urban resilience against natural hazards associated with poor desirability. According to this result, it is concluded that the region as a whole is resilient against natural hazards. In this direction, the resilience approach guidance to managers and practitioners use of flexible decisions and concerted policy for urban management. Build resilience in this area to support programmes should invest in organizing access to both external and existing resources in a fair manner, with a coordinated governance structure, and to facilitate social solidarity and support as part of disaster response. The findings also stress the importance of taking an ecological approach to studying resilience to disasters. Many factors from individual, community, and societal levels seem to be important in shaping resilience perceptions of natural hazards survivors. Understanding this evidence will help to validate and further develop indicators of resilience. Our findings point out that, despite existing pre-disaster vulnerabilities, resilience can be fostered following disasters if community members perceive availability of aid and support and mobilize resources Hence, psychosocial support programmes should invest in organizing access to both external and existing resources in a fair manner, with a coordinated governance structure, and to facilitate social solidarity and support as part of disaster response. The findings also stress the importance of taking an ecological approach to studying resilience to disasters. Many factors from individual, community, and societal levels seem to be important in shaping resilience perceptions of natural hazards survivors. Future research should conduct multiple levels of analysis with an all-hazards perspective to reveal how they can be integrated to increase adaptive capacities. Future research should focus on the process of capacity building through informing action to better prepare for disasters. Finally, this research tells us that due to the resiliency of the city will be able to have knowledge of all relevant indicators in the resiliency and reduce the adverse effects of these risks in urban communities
This is of cognitive research that has been done for analytical and descriptive. All data is obtained in the manner of library and field. The library of available resources and work conducted the form of a questionnaire survey. Questionnaires have been used of type Likert spectrum (numerous, high, high, somewhat, relatively low, low and very low), and its completion is done by fieldwork. Statistical population has problems of urban planning experts, among them 80 people were interviewed for targeted samples. Resiliency that includes four dimensions (economic, social, ecological, environmental and institutional). Was approved the validity of the index by 7 experts manage urban planning problems. For measuring reliability coefficient is calculated Cronbach's alpha equal to 0/79. For data analysis, the use of statistical analysis such as frequency, maximum and minimum, average and standard deviations, T-Test one sample test and Friedman nonparametric test
The results of the indicators of urban resiliency against natural hazards suggests that economic indicators 73/24 Average been determined and relatively low level, ie below the average level. Results of the test showed one sample T-Test is an indicator of economic status of urban resilience against natural hazards of poor utility. As well as the social, ecological, environmental and institutional (organizational) urban resilience against natural hazards associated with poor utility. Finally the 12 metropolitan Tehran metropolitan areautility resilience against natural hazards with respect to all dimensions were too weak. Friedman test results on the scoreboard indicators showed that the index of environmental sustainability (20/33) related to the ecology and environment in the first rank the importance of urban resilience and adaptability Index System (10/11) related to next institutional (organizational) is set as the least significant indicator. Also, significant chi-square statistic is calculated at a rate of 09/67 in three degrees of freedom at the level of 0.000. So, with a probability of 99% can be said that there is a significant difference between the performance rating of 80 specialist urban resilience dimensions (economic, social, ecological, environmental and organizational) against natural hazards, and not the distribution of the same rank.
This research been prepared with the aim of assessing the scale of urban resilience against natural hazards in District 12 of Tehran Metropolis. Results showed that social, environmental and institutional ecology and urban resilience against natural hazards associated with poor desirability. According to this result, it is concluded that the region as a whole is resilient against natural hazards. In this direction, the resilience approach guidance to managers and practitioners use of flexible decisions and concerted policy for urban management. Build resilience in this area to support programmes should invest in organizing access to both external and existing resources in a fair manner, with a coordinated governance structure, and to facilitate social solidarity and support as part of disaster response. The findings also stress the importance of taking an ecological approach to studying resilience to disasters. Many factors from individual, community, and societal levels seem to be important in shaping resilience perceptions of natural hazards survivors. Understanding this evidence will help to validate and further develop indicators of resilience. Our findings point out that, despite existing pre-disaster vulnerabilities, resilience can be fostered following disasters if community members perceive availability of aid and support and mobilize resources Hence, psychosocial support programmes should invest in organizing access to both external and existing resources in a fair manner, with a coordinated governance structure, and to facilitate social solidarity and support as part of disaster response. The findings also stress the importance of taking an ecological approach to studying resilience to disasters. Many factors from individual, community, and societal levels seem to be important in shaping resilience perceptions of natural hazards survivors. Future research should conduct multiple levels of analysis with an all-hazards perspective to reveal how they can be integrated to increase adaptive capacities. Future research should focus on the process of capacity building through informing action to better prepare for disasters. Finally, this research tells us that due to the resiliency of the city will be able to have knowledge of all relevant indicators in the resiliency and reduce the adverse effects of these risks in urban communities
Dr Abolfazl Meshkini, Mr Ali Mohammad Mansourzadeh, Mr Zeynab Shahrokhy Far, ,
Volume 6, Issue 3 (9-2019)
Volume 6, Issue 3 (9-2019)
Abstract
Identifying spatial patterns in vulnerability involves a comprehensive look at vulnerable points. And provides analytical power to the authorities. Therefore, it is necessary to recognize patterns of vulnerability so as to minimize the amount of damage to them in the event of a crisis. The city of Tehran, as the political and administrative center of the country, is faced with a variety of risks due to demographic burden and physical development. In this research, we tried to analyze the spatial distribution pattern of urban vulnerability to natural hazards in social and physical dimensions in Tehran's 7th region. The method of this descriptive-analytic study and the model used for trigonometric fuzzy logic. The results indicate that: According to the z score, the positive values are 1.96 up, which form the clusters of hot spots in the southeastern region of the arena; It is a sign of more vulnerability in these areas. Also, negative values of 1.96 and less, which are statistically significant and blue, have formed cold spots, And it is interpreted that low vulnerability zones are clustered in space and are mainly located in the northwest. Therefore, the lower the color range in the red and blue areas was less statistically significant to the point where this positive net worth is 1.65 that in this situation, the spatial behavior of the vulnerability is considered to be non-significant in terms of hot or cold clusters with high and low values and spatial autocorrelation that the map is also displayed in yellow.
Ms. Sousan Heidari, Dr. Mostafa Karimi, Dr. Ghasem Azizi, Dr. Aliakbar Shamsipour,
Volume 9, Issue 4 (3-2023)
Volume 9, Issue 4 (3-2023)
Abstract
Explaining the spatial patterns of drought intensities in Iran
Abstract
Recognition of spatial patterns of drought plays an important role in monitoring, predicting, confronting, reducing vulnerability, and increasing adaptation to this hazard. This study aims to identify the spatial distribution and analyze the spatial patterns of annual, seasonal, and monthly drought intensities in Iran. For this purpose, the European center Medium-Range Weather Forecast (ECMWF) data for the period 1979-2021 and the ZSI index were used to extract the drought intensities. To achieve the research goal and explain the spatial pattern of the frequency of drought intensities (Extreme, severe, moderate, and weak), spatial statistical methods such as global Moran’s I, Anselin local Moran’s Index, and hot spots were used. The results of the global Moran’s I showed that with increasing intensity, the spatial distribution of drought events has become clustered. The spatial distribution of the local Moran’s Index and hot spots also confirms this. Very clear contrast was observed in the local clusters of high (low) occurrence as well as hot (cold) spots of severe (Extreme) yearly droughts in the south, southeast, and east. In autumn, weak to Extreme droughts show a southeast-northwest pattern. But in spring and winter, the spatial pattern of drought is very strong as opposed to severe and moderate drought. Despite the relatively high variability of maximum positive spatial Autocorrelation of severe and Extreme monthly droughts, their spatial pattern is almost similar. The spatial clusters of severe and very severe droughts in the northwest, northeast, and especially on the Caspian coast, are a serious warning for the management of water resources, especially for precipitation-based activities, such as agriculture.
Introduction
Drought or lack of precipitation over some time is the most widespread natural hazard on the earth compared to its long-term average. This risk negatively affects various sectors such as hydropower generation, health, industry, tourism, agriculture, livestock, environment, and economy. To reduce these negative or destructive effects, it must be determined how often drought occurs during the period and in which areas it is most severe. Doing so requires determining the characteristics of the drought. These characteristics include area, intensity, duration, and frequency of drought. Discovering the geographical focus, recognizing the pattern governing the frequency of occurrence and temporal-spatial distribution as well as changes in the dynamics of this hazard facilitate an important role in drought monitoring, early warning, forecasting, and dealing with these potential hazards; this information can be used to create a drought plan by providing analysts and decision-makers with ideas about drought, helping to reduce the negative and vulnerable effects and ultimately make it easier to protect or replace for greater adaptation. Many researchers have been led by these approaches to the use of statistical analysis. Numerous studies have been conducted in the study of climatic phenomena such as drought with space statistics techniques in various regions, including China, India, South Korea, and even Iran. Part of the domestic research on spatial patterns of drought is without the use of spatial statistics and a limited number of others who have used these analyzes have only studied the overall intensity of drought and have not studied the spatial patterns of different drought intensities. The main purpose of this study is to identify the distribution and spatial patterns of drought intensities in Iran using spatial analysis functions of spatial statistics based on the frequency of drought intensities (Extreme, severe, moderate, and weak) with yearly, seasonal and monthly multi-scale approach. Therefore, this study will answer the questions: a) What is the spatial distribution of drought intensity data in Iran? And b) What is the variability of spatial patterns of Iranian droughts at different time scales?
Material &Method
ERA5 monthly precipitation data for a period of 43 years from 1979 to 2021 were used for this study. an array of dimensions of 78×59×504 of data were formed in MATLAB software in which 78×59 is the number of nodes with a spatial resolution of 0.25 degrees and 504 represents the month. After creating the database, the ZSI index was used to calculate the severity of drought in annual, seasonal, and monthly comparisons. Finally, to achieve the research goal and explain the spatial pattern governing the frequency of drought intensities (Extreme, severe, moderate, and weak), spatial statistical methods such as global Moran’s I, Anselin local Moran I and hot spots was used.
Discussion of Results
Due to its ecological conditions, geographical location, and location in an arid and semi-arid region of the world, Iran is among the most vulnerable countries due to natural hazards, including drought. It has experienced many severe droughts in the last century. The occurrence of drought and its effects is one of the major challenges of water resources management in this century. The results of the Global Moran’s Index for all three annual, seasonal, and monthly scales showed a highly clustered pattern of drought events in the country. Spatial clustering of the occurrence of severe and Extreme yearly droughts in the eastern, southeastern, and southern regions is also an interesting result. These conditions are due to low precipitation and high spatial variation coefficient in these areas. This contrast of spatial clusters of drought intensities indicates the relationship between drought and temporal-spatial anomalies of precipitation so that with increasing precipitation, spatial variability of precipitation decreases, and consequently spatial homogeneity of precipitation increases. severe and moderate-intensity spots in the south-southeast in autumn and spring can be affected by fluctuations in the beginning and end of the monsoon season in South Asia due to the high variability of atmospheric circulation at the beginning and end of precipitation in these areas. Some studies have also shown the relationship between precipitation in these areas and the monsoon behavior of South Asia. Extreme drought events in winter and spring have had a positive spatial correlation pattern in the southwest, west, and northwest. However, precipitation at this time of year is concentrated in these areas. Warm clusters or concentrations of very severe drought events in the northern strip of the country, especially in the Caspian region, can be due to the high variability of precipitation at the beginning of the annual precipitation season (late summer and early autumn). Observations of these conditions in the northern strip indicate that an event with a high frequency of severe droughts, even in rainy areas, should not be unexpected. Spatial clusters of Extreme, severe, moderate, and weak drought every month using both local Moran and hot spots statistics show the fact that in Iran, the most severe droughts have occurred in the western, northwestern, and coastal areas of the Caspian Sea. However, the absence of severe droughts or spatial clusters has been the occurrence of low drought in the southeast and to some extent in the south. On a yearly scale, the south, southeast, and east have played a significant role in the spatial cluster of severe and extreme droughts. So that these areas of the country have had positive spatial solidarity. However, in these areas, negative spatial correlation prevailed in the autumn for severe drought. This may indicate an anomaly and a tendency to concentrate more precipitation in Iran, as well as many changes in seasonal and local precipitation regimes. According to the research results, a high incidence of severe and extreme drought on all three scales (monthly, seasonal and annual) even in the wettest climate of the country (northern Iran, especially the southern shores of the Caspian Sea) shows that High-intensity droughts can occur in all parts of the country, regardless of the weather conditions.
Keywords: Natural hazards, spatial patterns, Moran statistics, spatial autocorrelation, hot spots
Dr Abdolmajid Ahmadi, ,
Volume 10, Issue 1 (5-2023)
Volume 10, Issue 1 (5-2023)
Abstract
Extended abstract
Landslide risk zoning is one of the basic measures to deal with and reduce the effects of landslides. Vernesara watershed is one of the areas where many landslides have been observed in different parts of it. In this research, in order to zone the risk of landslides using the entropy index, first the ranges of landslides were determined, then the effective factors in the occurrence of range movements were prepared in the ArcGIS software environment, and a landslide susceptibility map of the studied area was prepared. . The prioritization of effective factors using Shannon's entropy index showed that the slope layers, land use, surface curvature, topographic humidity index and topographic position index had the greatest effect on the occurrence of landslides in the region. Also, zoning landslide sensitivity with the mentioned model and evaluating its accuracy using the ROC curve shows the very good accuracy of the model (79.6 percent) with a standard deviation of 0.0228 for the studied area. The zoning map shows that the low-risk areas cover only 13% of the area and more than 56% of the area is in the area with high risk of landslides, which indicates the high potential of the area in the occurrence of landslides. . Construction at a distance from fault lines, waterways and the steep Asmari Formation and safety of communication routes are the most important measures to reduce the amount of damage caused by landslides in Vernesara watershed.
Key words: natural hazards, landslide, entropy, folded Zagros.
Farzin Mahmoudi, Hamed Ghadermazi, Dr Leila Mafakheri,
Volume 10, Issue 3 (9-2023)
Volume 10, Issue 3 (9-2023)
Abstract
Introduction
Every year, natural hazards occur with great severity and sometimes they destroy people completely Today, science has proven that natural hazards cannot be avoided. He simply considered a natural event and did not pay attention to their complex causes. Most of these causes are attributed to a combination of socio-economic factors. But it is possible to reduce their consequences by carefully planning against such accidents. When these hazards and disasters have a human aspect and affect humans, human activity and human environment, they are introduced as crisis.
According to the statistics of the Food and Agriculture Organization of FAO, 5-15% of agricultural products are lost annually due to damage caused by frost and frost, this number reaches more than 40% for some sensitive garden products, especially almonds, pistachios and apricots. . The amount of damage caused by this complication in Iran is more than 500 million dollars. Rural settlements suffer the most damage after a drought. Thus, there is a significant relationship between the risk management of agricultural activities with most environmental components and natural disasters such as drought, flood, frost, etc. up to the 99% confidence level. In order to reduce the effects of natural hazards in rural areas, there are various strategies that can be used to manage the risk of natural hazards , diversification of agricultural productio, contract farming and increasing farmers' awareness of natural hazards.
Gardens are one of the most important sources of livelihood in rural areas in Tuysarkan city in Hamadan province. Tuysarkan city has 7600 hectares of garden lands, which includes 14% of all gardens in Hamadan province. Due to its geographical location, weather conditions and geological structure, this city is exposed to various natural hazards. Among them, we can mention drought, land subsidence, frost and earthquake. Identifying natural hazards in Tuiserkan city and the effects of these hazards, as well as the actions of the local community to reduce existing hazards, are among the most important goals of this research.
Research Method
In the current research, we tried to use different methods so that the subject can be better investigated from different angles of research. This research is applied in terms of purpose and based on a descriptive-analytical research plan and is considered analytical-exploratory in nature. The research data has been collected through questionnaires and official statistics of institutions such as Iran Water Resources Management Company and the country's Meteorological Organization. Data analysis has been done descriptively and analytically using Excel and GIS software.
Research Results
The results of the research show that the most important hazards in the field of horticulture in the central part of Tuiserkan are frost in the first place and drought and hail in the second and third places. Also, other results show that the most important risk that affects the livelihood and income of the local community is the annual frost of gardens, which has caused the migration of some family members, and the amount of income is also affected by this risk. Regarding the solutions proposed by the local community to reduce the effects of natural hazards on walnut orchards, providing financial facilities, using information technology, and planting cold-resistant species were among the most important solutions proposed by the local community. Regarding the analysis of open questions and conducted interviews, Netaj shows that the most important measures to reduce the effects of natural hazards (freezing, drought and hail) on walnut orchards are: heating the orchard environment, using resistant and using drip irrigation. Also, the evaluation of the analysis of local knowledge and the experience of the past regarding measures to reduce the effects of frost on walnut orchards shows that the actions of the past are not very popular with the current generation and they are doing the same thing that the past did. With this difference, the ancients believed more in luck and destiny than in practical action. Finally, from the point of view of the local community, the best measure to reduce the effects of frost on the walnut orchards in the central part of Tuiserkan is genetic modification of the orchards and cultivation of resistant species.
Every year, natural hazards occur with great severity and sometimes they destroy people completely Today, science has proven that natural hazards cannot be avoided. He simply considered a natural event and did not pay attention to their complex causes. Most of these causes are attributed to a combination of socio-economic factors. But it is possible to reduce their consequences by carefully planning against such accidents. When these hazards and disasters have a human aspect and affect humans, human activity and human environment, they are introduced as crisis.
According to the statistics of the Food and Agriculture Organization of FAO, 5-15% of agricultural products are lost annually due to damage caused by frost and frost, this number reaches more than 40% for some sensitive garden products, especially almonds, pistachios and apricots. . The amount of damage caused by this complication in Iran is more than 500 million dollars. Rural settlements suffer the most damage after a drought. Thus, there is a significant relationship between the risk management of agricultural activities with most environmental components and natural disasters such as drought, flood, frost, etc. up to the 99% confidence level. In order to reduce the effects of natural hazards in rural areas, there are various strategies that can be used to manage the risk of natural hazards , diversification of agricultural productio, contract farming and increasing farmers' awareness of natural hazards.
Gardens are one of the most important sources of livelihood in rural areas in Tuysarkan city in Hamadan province. Tuysarkan city has 7600 hectares of garden lands, which includes 14% of all gardens in Hamadan province. Due to its geographical location, weather conditions and geological structure, this city is exposed to various natural hazards. Among them, we can mention drought, land subsidence, frost and earthquake. Identifying natural hazards in Tuiserkan city and the effects of these hazards, as well as the actions of the local community to reduce existing hazards, are among the most important goals of this research.
Research Method
In the current research, we tried to use different methods so that the subject can be better investigated from different angles of research. This research is applied in terms of purpose and based on a descriptive-analytical research plan and is considered analytical-exploratory in nature. The research data has been collected through questionnaires and official statistics of institutions such as Iran Water Resources Management Company and the country's Meteorological Organization. Data analysis has been done descriptively and analytically using Excel and GIS software.
Research Results
The results of the research show that the most important hazards in the field of horticulture in the central part of Tuiserkan are frost in the first place and drought and hail in the second and third places. Also, other results show that the most important risk that affects the livelihood and income of the local community is the annual frost of gardens, which has caused the migration of some family members, and the amount of income is also affected by this risk. Regarding the solutions proposed by the local community to reduce the effects of natural hazards on walnut orchards, providing financial facilities, using information technology, and planting cold-resistant species were among the most important solutions proposed by the local community. Regarding the analysis of open questions and conducted interviews, Netaj shows that the most important measures to reduce the effects of natural hazards (freezing, drought and hail) on walnut orchards are: heating the orchard environment, using resistant and using drip irrigation. Also, the evaluation of the analysis of local knowledge and the experience of the past regarding measures to reduce the effects of frost on walnut orchards shows that the actions of the past are not very popular with the current generation and they are doing the same thing that the past did. With this difference, the ancients believed more in luck and destiny than in practical action. Finally, from the point of view of the local community, the best measure to reduce the effects of frost on the walnut orchards in the central part of Tuiserkan is genetic modification of the orchards and cultivation of resistant species.
Saeedeh Koohestani, Bijan Sayyafzadeh, Abdolreza Sarvghad Moghadam, Mahdi Sharifi,
Volume 10, Issue 4 (12-2023)
Volume 10, Issue 4 (12-2023)
Abstract
By increasing the number of process industrial plants because of societies necessity to their productions, a new branch of accidents caused by various occurred process failures and their effect on the societies and environment and economy has been introduced. Beside it, the increase of the accidents because of natural hazards effect on the industrial plants and their huge costs to the societies and governments and high vulnerability of plants and urbanized territory to the branch of the accidents, increased the attention to this type of accidents. However, in many parts of the world still do not pay attention seriously to this issue and by considering them as very low probability accidents, eliminate paying attention and accepting the responsibility of them while the frequency of such accidents is under growing! In this article according to the existing statistics, an evaluation and comparison of consequences of natural hazards that caused NaTech events has been done. The purpose of the NaTech events is process events that triggered because of natural hazards that are known as events with low probability and high consequences that can affect a wide area and cause huge accidents associated with domino effects. After introducing and categorizing NaTech events, a comparison of their distribution and consequences of these events in Iran and the world has been done according existing articles and researches. Researches shows opposite of the natural hazards and their effects on some structures and infrastructures, Natech events has not been paid under attention enough in Iran. While the variety of industrial plants and their structures in Iran is high, their existing condition and repairing and maintenance of them is not proper and according collected statistics in this article, the potential of NaTech events is also high in country. In the first step, to increase the preparedness for NaTech events, review of effective world experiences in this field is recommended. Recognition of past events and categorizing them and codification of data that should be included in safety reports and scenarios evaluation and considering the domino effects and review the recommendations in this field are parts of this step.
Dr. Habibollah Fasihi, Dr. Taher Parizadi,
Volume 10, Issue 4 (12-2023)
Volume 10, Issue 4 (12-2023)
Abstract
Urban planners consider historical fabric as the beating heart of cities. However, cities and specifically their historical fabrics are constantly under influence of natural and human-induced hazards. This study aimed to assess the vulnerability of Ferdowsi neighborhood as an example of Tehran’s historical fabric. The data was obtained from geographical information system (GIS) files and a survey, as well as historical contexts and documents were analyzed as part of this study. Ten municipal experts were also asked to provide a score of 1 to 5 for each of the 29 indicators compared to standard levels. The mean value of these scores was then used to evaluate the role of each parameter in the vulnerability of this neighborhood. Study findings indicate a high potential for the occurrence of natural and human-induced hazards in the study area. The abundance of unstable multistory buildings and derelict electricity and water networks, storage of flammables in warehouses, and lack of sewage network for half of the buildings were the most significant factors contributing to the vulnerability of this ancient fabric. Problems such as insecurity, drug abuse in public spaces, overcrowding and daytime congestion have also led to rapid relocation of neighborhood residents, who subsequently were replaced by commercial activities and warehouses. In conclusion, numerous problems are contributing to the vulnerability of historical fabric of this neighborhood and such problems are highly likely to be applied to other urban historical fabrics in Tehran.
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