Search published articles
Showing 403 results for Type of Study: Research
Ali Eshghei, Hossein Nazmfar, Ata Gafari,
Volume 7, Issue 2 (8-2020)
Volume 7, Issue 2 (8-2020)
Abstract
Spatial analysis physical resiliency City Earthquake Model Condorcet Case study: ten districts of the region one of Tehran Abstract Earthquake as one of the most devastating and destructive natural hazards; especially in developing countries, it has been a long time ago With the collapse of buildings and urban infrastructure, Imports a lot of damage to property and assets in urban areas and around them. In response to this, international organizations' strategies to mitigate disasters have made their societies resilient to natural disasters. And considers it within the framework of the Higgo for the years 2005-2015. In fact, the goal of this approach is to reduce the vulnerability of cities and to strengthen citizens' abilities to deal with the dangers of threats such as natural disasters. Considering that the area of a Tehran city due to its proximity to faults such as Mashaa fault, North Tehran fault Also, the effects of faults in and around the region such as Niavaran fault, Mahmoodieh fault and Darabad fault (Banamieh) are located in a region with a high seismic hazard. Assessment of resilience of the region to earthquake risk and resilience of the region In order to reduce the risks of earthquakes in this area is very important. Accordingly, the present study was conducted with the aim of assessing the resilience situation of the 10th district of Tehran municipality district against earthquake. The method of this research is descriptive-analytical with a purposeful purpose. The research area of the 10th Region is a municipality of Tehran. The raw data used by the Tehran Municipality Information Technology Organization has been obtained. To determine the relative importance of each component used in research According to experts from the Urban Planning Area, the Network Analysis Process (ANP) has been used in the form of Super Decisions software. Then, to rank 10 areas of a Tehran municipality district against earthquake, Multi-criteria decision making models (MCDMs) including TOPSIS, VIKOR, HAW and SAW models have been used. Considering that different methods have been used to rank the areas Different results have been achieved, to overcome the contradictions between the various ratings of the regions in each of the models, and a single result has been used to rank the areas of the congregation's integrated model. Finally, in order to speak, the results of the model used in the ArcGIS environment were mapped. In this research, for the spatial analysis of the resilience of the 10 district areas of a Tehran municipality from the results four models (TOPSIS, VIKOR, HAW and SAW) were used. Based on the results of the TOPSIS technique, areas 8, 3 and 2 of resilience are large, areas 7 and 4 of the moderate resilience, Areas 5, 1, 6 and 10 have low resilience and area 9 has very little resilience against the earthquake. Based on the results of the VIKOR model, areas 3 and 4 of the resilience, regions 2, 7, 5, 9, 8, 6 and 10 of the moderate resilience Medium and area one have low resilience against earthquake. Based on the results of the HAW model, area 3 of the high resilience, regions 2, 7, 8 and 4 of the moderate resilience and areas 10, 1, 6 and 9 are of low resilience. In this model, no area has been found to be very resilient. Based on the results of the SAW model, regions 3, 2, 8, and 7 are in the range of many resiliences, regions 5 and 4 in the moderate resilience range, Area 9 is in the low resilience range and areas 10, 6 and 1 are in the low resilience range against earthquakes. In this study, we evaluated the resilience situation in the districts of Tehran municipality district in an earthquake Multi-criteria decision-making methods including TOPSIS, VIKOR, HAW and SAW were used, Then a CONDORCET integrated model was used to achieve a single result of these analyzes. The results of the Canadian model, which is the result of a combination of the final results of the models (Tapis, VIKOR, HAW and SAW), show that Areas 2, 4, 5, and 3 are of high resilience, areas 7, 8 and 1 of the moderate resilience, 10 and 6 of the resilience, and area 9 of the resilience is very low against earthquakes. Which should be prioritized in future plans. Although it is possible to assess the vulnerability of urban areas by using different models and mapping them in the region's resilience to the earthquake crisis, a significant part of post-crisis casualties fell but this will not be achieved until the authorities are seriously determined. Keywords: Resilience, Earthquake, Multi-criteria Decision Making Methods, Tehran Municipality Area
Dr. Baqer Kord, Dr Amin Rahati, Dr Peyman Mahmoudi, Mr Parviz Khosravi, Ms Harir Bidar,
Volume 7, Issue 2 (8-2020)
Volume 7, Issue 2 (8-2020)
Abstract
Prioritizing the counties of Sistan and Baluchestan province in order to optimize the management of drought budget
Abstract
Drought is one of the most significant natural hazards which affects various aspects of human life with its gradual, slow and creeping occurrence. As a disastrous climate phenomenon, it directly impacts on human communities through making changes in access to water resources, and imposes enormous economic, social and environmental costs on various communities. One of the strategies governments always use to compensate the damages that droughts impose on various economic, social and environmental sectors is to include special financial loans in the form of grants, special development credits, special structural projects, and so on. Therefore, in this regard, a lot of financial aids have been allocated by the government for it. But, sometimes, it is observed that the allocation and distribution of drought credits among different cities of the province have been more influenced by political, ethnic, and religious interests rather than by the severity of the drought and its detrimental effects on various economic, agricultural, and social sectors. Therefore, in this study, it has been tried to present a method based on an optimization model in order to take a step in optimizing the management of drought budget based on realities in Sistan and Baluchestan province in south-east of Iran.
In this study, the indicators proposed by the Cabinet of Ministers of the Islamic Republic of Iran for reducing the effects of drought were applied to manage the optimal distribution of drought budgets among the cities of Sistan and Baluchestan province in southeast of Iran. These indicators were population, having urban and rural drinking water, vulnerability of water resources, surface area under cultivation, number of users of agricultural sector, annual consumption of agricultural water, and rainfall. Using the figures given in the 2011 statistical yearbook, numerical values for each of these indices were obtained. But given that these indices are not of equal importance in each city and some may be more important in one city and less important in another, the Analytical Hierarchy Process (AHP) technique using paired comparison method was applied to determine the relative importance of these indices in Sistan and Baluchestan province. Using this technique, a relative weight was determined for each of these indicators and for each city. In addition to determining the weight of these indices, it was needed to convert droughts in the province to numerical values. In this study, to analyze droughts in Sistan and Baluchestan province, Standardized Precipitation Index (SPI), which is one of the proposed indicators of World Meteorological Organization (WMO) has been used for a period of 30 years (1984-2014) and for 6 synoptic stations.
The results of drought analysis in Sistan and Baluchestan province in an annual scale showed that the frequency distribution of different drought levels in Sistan and Baluchestan province has not been uniform, with the most droughts occurring in this 30 year period in northern part of the province (Zabol and Zahedan) including 14 and 13 repeated cases; respectively, with the lowest in central part of Baluchistan (Khash and Saravan) including 11 repeated cases. But, what should be noted after the frequency of droughts is the persistence and durability of droughts. As a result, weak but long-lasting droughts can be much more damaging than severe but short-lived droughts. Sistan and Baluchestan province has been under drought with varying degrees of severity from the water year of 1998-1999 to the water year of 2005-2006. But in the meantime, the north of Sistan and Baluchestan province (Zabol station) has a condition which is very different from other parts of the province. The north of Sistan and Baluchistan province has been experiencing severe droughts for 14 years from the year 1999-2000 to 2012-2013 with the exception of the year 2004-2005. It has been the long-term drought persistence in the province that has caused many environmental, economic and social problems, such as the drying up of Lake Hamoun and the water reduction in the Hirmand River in the north of the province, and severe reduction of groundwater resources in central Baluchistan. Therefore, given that Sistan and Baluchestan province has experienced 7 years of continuous drought between the two water years of 1998-1999 to 2009-2010, these seven years were chosen as examples, and the ant colony algorithm was implemented on them.
Based on the selected criteria and the proposed method, it seems that the combination of Analytic hierarchy process (AHP) technique and Ant colony algorithm can formulate an intelligent system to determine the priority of the cities in Sistan and Baluchestan province during droughts for allocating the optimal budget and reducing the harmful effects of droughts. Based on the prioritization maps of optimal drought budget allocation among the cities in Sistan and Baluchestan province, an almost good agreement can be observed between the results and the realities existing in the province.
Keywords: Sistan and Baluchestan, ant colony algorithm, Analytical Hierarchy Process, budget, Management
Dr. Aliakbar Shamsipour, Mr. Ayoub Jafari, Mr. Hesam Bostanchi,
Volume 7, Issue 2 (8-2020)
Volume 7, Issue 2 (8-2020)
Abstract
Occurrence conditions for severe snow blizzard in the west-north of Iran
Abstract
The blizzard incident is one of the climatic hazards that occurs due to the combination of other climatic factors such as temperature (below zero), snow and wind (at 15 m/s). In this research, the conditions of blizzard in Northwest of Iran are carried out using statistical methods. By analyzing all the meteorological codes of the blizzard (36, 37, 38 and 39) during the statistical period from 1987 to 2016 for 11 synoptic stations of the study area, codes with severe blizzard (37, 39) were selected. Then, using the geopotential height, wind and Leveling temperature of 500 and 850 hpa, obtained from the NCEP/NCAR open source database, the synoptic patterns of blizzard incident analyzed. Statistical analysis of the relationship between the effects of geographic factors on severe blizzard has shown that the factor of height has the greatest effect on intensity, increase and incident spatial differences of this phenomenon. The study of the synoptic patterns of the incident of the blizzard phenomenon showed that five main patterns play a role in creating it in the region. The synoptic patterns of development include the formation of a low cut-off center, a long landing passage from Iran, the formation of a relatively deep and drawn Mediterranean East, The rectangular system is a rex-shaped system and is an umbilical bundle system. Among the patterns obtained, the patterns that were bundled were, the most important role in the survival and transfer of flows associated with cold, and other patterns, despite the frequency they had, were periodically of severity and weakness.
Keywords: Blizzard; North West; Wind speed; Temperatures below zero; Synoptic patterns
Human life is always affected by climatic phenomena, especially the hazards of the two variables of temperature and wind. One of the most important simultaneous phenomena of these two variables is the blizzard, which is caused by heavy snow, stormy winds, and very low temperatures. This climate risk can cause damage to various areas of horticulture, agriculture, urbanization, transportation, and so on. This phenomenon is present in regions such as Canada and North America with a cold weather wave that results from turbulence in the winters and damages the lawns in these areas. There are plenty of local storm in the polar regions and it lasts for a few days. For example, the wind in the Adelie land in the Antarctic is so severe that the area is known as the storm Land. In Iran, the most significant blizzard occurred in mid-February 1350, resulting in the deaths of more than 4,000 people across the country. In this research, considering the characteristics of the blizzard phenomenon at the time of occurrence (severity, continuity, expansion, and time of occurrence), the study has been conducted to determine the statistical synoptic patterns in the northwest region.
In this research, the studied area is northwest of Iran, which includes 6 provinces (Ardebil, West Azarbaijan, East Azarbaijan, Zanjan, Kurdistan, Kermanshah, Hamedan). In order to study, the days with the blizzard phenomenon in the form of 3 hours and in codes of this phenomenon (36, 37, 38 and 39), were obtained from the establishment of the stations studied by 2016. In the following, for precise examination, stations with 30 years of statistic from 1987 to 2016 were identified and the statistical (frequency, daily, monthly and annual frequency) codes 39 and 37 were studied. Finally, the relationship between blizzard with the latitude and elevation in the studied stations was determined. To assess the statistical results, the correlation coefficients (R) and coefficient of determination (R2) were used.
In the second part, the identification of synoptic patterns was done by Principal Component Analysis in MATLAB software and ocular method. The criterion for identifying synoptic patterns, the days where codes 37 and 39 are more than 1 time (3 hours) within 24 hours or two days behind each other at the stations studied. In order to determine the patterns, at first, the average geopotential data of the 500-hpa level from 1987 to 2016 were obtained from a range of 10-70 degrees north latitude and 0-80 degrees east longitude with a spatial resolution of 2.5 * 2.5 from the NCEP / NCAR data.
Statistical analyzes on the relationship between the effect of geographic factors on severe blizzard showed that the factor of height had the greatest effect on the intensity, magnitude and spatial differences of this phenomenon. In sum, the most important factor in the occurrence of this phenomenon is due to atmospheric conditions and synoptic patterns of the region. In this study, the most frequent occurrence of codes 37 and 39 in all stations studied was at Sardasht station and Khalkhal station, respectively. Also, the statistical study of the frequency of the annual and monthly occurrence of each code showed that code 39 in 1990 and code 37 in the years 1989 and 1990, as well as in January, had the highest frequency of each of the two codes.
Investigating the patterns of the occurrence of the blizzard phenomenon showed that five main patterns have contributed to its creation in the region, the first pattern due to the formation of a low cut-off center, which, with the cold weather in Central and Eastern Europe, has reduced the temperature in the northwest. The second pattern is due to the high landing passage from Iran, which has crossed the descent from a cold and cold weather zone from Europe to Iran. The third pattern is the location of the studied area in the relatively moderate, dragged, eastern Mediterranean wavelength, causing cold weather to fall to the northwest. The fourth pattern, with the formation of a Rex-type blockade on the Mediterranean, has led to the transfer of cold air from Eastern Europe, Kazakhstan, and high latitudes to Iran. The fifth pattern, with the formation of a blockade, has caused cold weather in northern Europe and Central Asia to enter the country from the north, causing a drop in temperature in the region.
Among the known patterns, the patterns that were blocked (pattern 4 and 5) played the most important role in the survival and transfer of cold fluxes and even drawn to lower latitudes. Other patterns, despite frequent periods, provide conditions for the occurrence of this phenomenon and, unlike the blocking patterns, have had severity and weakness.
Keywords: Blizzard; North West; Wind speed; Temperatures below zero; Synoptic patterns
Nima Sohrabnia, Dr Bohlol Alijani, Dr Mehry Akbari,
Volume 7, Issue 2 (8-2020)
Volume 7, Issue 2 (8-2020)
Abstract
Modeling the discharge of rivers in selected watersheds of Guilan province during climate change
Abstract
In this essay, we investigated the effects of climate change on the rivers of selected basins of Guilan province, one of the northern provinces of Iran for the period 2020 to 2050 under three climate scenarios: RCP2.6, RCP4.5, RCP8.5. For this purpose, rainfall and temperature data from 45 climate data stations and 20 hydrometric stations from 1983 to 2013 were used. The average precipitation and temperature at basin level were calculated by drawing both Isohyet and Isothermal lines by usage Kriging method. Mann-Kendall and Sen’s slope estimator tests were used to determine the significance of the data trends and their slope, respectively. The results showed that temperature has increased in all catchments during the study period and this trend was significant in most of them but no significant trend was observed for precipitation. Discharge has also decreased in most basins and this trend was significant in Shafarood, Navrood and Chafrood basins. However, for future periods, precipitation is not significant in any of the climate scenarios, but the temperature is increasing in all scenarios except for the RCP2.6 scenario. Rivers discharge in the RCP2.6 scenario is not significant in any of the basins, but in the RCP4.5 scenario the Shafarood and Ghasht-Roodkan catchments have a significant reduction in the 95% confidence level. In the RCP8.5 scenario, the Chafrood and Shafarood basins have a 99% confidence reduction trend.
Population and technology growth, increased water consumption and climate change have led many researchers to study and model water resources in the present and future periods. Especially in areas like Iran that are facing a lot of water stresses. The purpose of the present study, which was carried out in the Guilan province, is to provide information on the present and future status of surface water resources, and to prepare them for facing the problems of potential water resources exploitation.
In this study 45 synoptic, evaporative and rain gauge stations and 20 hydrometric stations data with sufficient statistics were used. The period of study is also between 1983 and 2013. In this regard, after calculating the average precipitation and temperature values of each basin using Kriging model, first, the annual average of precipitation and temperature values of each basin were calculated. Then, multivariate regression was used to obtain the regression equations between precipitation, temperature and discharge data, then by using SDSM model and climate scenarios (RCP2.6, RCP4.5, RCP8.5) future temperature and precipitation data were generated. By placing these generated data in the Created regression equations, the discharge of the rivers was calculated for the period 2020 to 2050. The trend of time series and their slope were analyzed respectively by Mann-Kendall and Sense tests.
The study of the annual average precipitation trend of the selected catchments during the study period showed that all the basins had no significant trend at any of the confidence levels (95% and 99%). However, for the temperature there is an increasing trend. In Chafrood, Zilaki, Chalvand, Lavandevil, Tutkabon, Chubar, Lamir, Hawigh, Dissam, Shirabad, Ponel, Samoosh, and Polrood basins there is significant trend at 95% confidence level. For the Hawigh River basin there is significant trend at 99% confidence level. Also in most of the basins there is a downward trend of rivers discharge. In addition, in the three basins of Chafrood, Navrood and Shafarood, there is a significant decreasing trend at 95% confidence level, which is also significant at 99% confidence level for Navrood and Shafarood rivers.
Analysis of future data showed that precipitation is not significant in any of the climate scenarios, but the temperature is increasing in all scenarios except for the RCP2.6 scenario in RCP2.6 scenario. For rivers discharge there was no significant trend in any of the basins, but in RCP4.5 scenario there is a significant decrease in 95% confidence level in Shafarood and Ghasht-Roodkan. Also in the RCP8.5 scenario, a significant decreasing trend of flow discharge at 99% confidence level is observed for Chafrood and Shafarood basins. Finally, the catchments were grouped according to the level of risk involved with decreasing discharge. The results of grouping showed that most of the basins in the three scenarios were in the medium risk group but Shafarood, Chafrood and Ghasht-roodkhan watersheds have higher risk than the other watersheds, respectively.
Investigation of river discharge trends for the period 2020 to 2050 in different scenarios showed that the basins of Ghasht-roodkhan, Chafrood and Shafarood are more sensitive to climate change than other basins. Overall, escalating temperature trends in future and precipitation irregularities can create very difficult conditions in future to use these resources. Especially, this study's concordance with other studies in Iran and the study area confirms that such crises are more likely to occur..
Keywords: Climate Change Scenarios, Rivers Discharge, Man-Kendall, Sen’s Slope estimator, Guilan Province
Abstract
In this essay, we investigated the effects of climate change on the rivers of selected basins of Guilan province, one of the northern provinces of Iran for the period 2020 to 2050 under three climate scenarios: RCP2.6, RCP4.5, RCP8.5. For this purpose, rainfall and temperature data from 45 climate data stations and 20 hydrometric stations from 1983 to 2013 were used. The average precipitation and temperature at basin level were calculated by drawing both Isohyet and Isothermal lines by usage Kriging method. Mann-Kendall and Sen’s slope estimator tests were used to determine the significance of the data trends and their slope, respectively. The results showed that temperature has increased in all catchments during the study period and this trend was significant in most of them but no significant trend was observed for precipitation. Discharge has also decreased in most basins and this trend was significant in Shafarood, Navrood and Chafrood basins. However, for future periods, precipitation is not significant in any of the climate scenarios, but the temperature is increasing in all scenarios except for the RCP2.6 scenario. Rivers discharge in the RCP2.6 scenario is not significant in any of the basins, but in the RCP4.5 scenario the Shafarood and Ghasht-Roodkan catchments have a significant reduction in the 95% confidence level. In the RCP8.5 scenario, the Chafrood and Shafarood basins have a 99% confidence reduction trend.
Population and technology growth, increased water consumption and climate change have led many researchers to study and model water resources in the present and future periods. Especially in areas like Iran that are facing a lot of water stresses. The purpose of the present study, which was carried out in the Guilan province, is to provide information on the present and future status of surface water resources, and to prepare them for facing the problems of potential water resources exploitation.
In this study 45 synoptic, evaporative and rain gauge stations and 20 hydrometric stations data with sufficient statistics were used. The period of study is also between 1983 and 2013. In this regard, after calculating the average precipitation and temperature values of each basin using Kriging model, first, the annual average of precipitation and temperature values of each basin were calculated. Then, multivariate regression was used to obtain the regression equations between precipitation, temperature and discharge data, then by using SDSM model and climate scenarios (RCP2.6, RCP4.5, RCP8.5) future temperature and precipitation data were generated. By placing these generated data in the Created regression equations, the discharge of the rivers was calculated for the period 2020 to 2050. The trend of time series and their slope were analyzed respectively by Mann-Kendall and Sense tests.
The study of the annual average precipitation trend of the selected catchments during the study period showed that all the basins had no significant trend at any of the confidence levels (95% and 99%). However, for the temperature there is an increasing trend. In Chafrood, Zilaki, Chalvand, Lavandevil, Tutkabon, Chubar, Lamir, Hawigh, Dissam, Shirabad, Ponel, Samoosh, and Polrood basins there is significant trend at 95% confidence level. For the Hawigh River basin there is significant trend at 99% confidence level. Also in most of the basins there is a downward trend of rivers discharge. In addition, in the three basins of Chafrood, Navrood and Shafarood, there is a significant decreasing trend at 95% confidence level, which is also significant at 99% confidence level for Navrood and Shafarood rivers.
Analysis of future data showed that precipitation is not significant in any of the climate scenarios, but the temperature is increasing in all scenarios except for the RCP2.6 scenario in RCP2.6 scenario. For rivers discharge there was no significant trend in any of the basins, but in RCP4.5 scenario there is a significant decrease in 95% confidence level in Shafarood and Ghasht-Roodkan. Also in the RCP8.5 scenario, a significant decreasing trend of flow discharge at 99% confidence level is observed for Chafrood and Shafarood basins. Finally, the catchments were grouped according to the level of risk involved with decreasing discharge. The results of grouping showed that most of the basins in the three scenarios were in the medium risk group but Shafarood, Chafrood and Ghasht-roodkhan watersheds have higher risk than the other watersheds, respectively.
Investigation of river discharge trends for the period 2020 to 2050 in different scenarios showed that the basins of Ghasht-roodkhan, Chafrood and Shafarood are more sensitive to climate change than other basins. Overall, escalating temperature trends in future and precipitation irregularities can create very difficult conditions in future to use these resources. Especially, this study's concordance with other studies in Iran and the study area confirms that such crises are more likely to occur..
Keywords: Climate Change Scenarios, Rivers Discharge, Man-Kendall, Sen’s Slope estimator, Guilan Province
Dr. Javad Sadidi, Mrs. Zahra Judaki, Hani Rezayan,
Volume 7, Issue 2 (8-2020)
Volume 7, Issue 2 (8-2020)
Abstract
Designing and implementing a 3D indoor navigation web application
Extended abstract
Nowadays, due to the complexity of interior space of buildings, the need arises for indoor navigation inside such spaces. Indoor navigation systems may be helpful for emergency evacuation of the crowd in natural hazards such as earthquake as well as human-made disasters. These systems can also act as a decision support system for officials. Literature survey on indoor navigation services shows that a large number of researches have been conducted around designing and implementing such systems but automatic indoor spaces topology extraction of the current building information models remains as a challenge. This research aims to introduce, design and implement a web-based indoor navigation system using CityGML data model in LOD4 (level of detail) to overcome the mentioned problem.
The architecture of the current research is a browser-based web application service such that the data model processing and graph creation is implemented on the server side, the client interface and calculated path are represented on the client side (browser). Through the CityGML data model processing, firstly, the building navigable spaces such as room floor, doors and stairs are extracted and then, each space as a node and the connections between the nodes are defined as edges, are imported to the navigation graph. Programming on the server side has been performed by Python language and web development languages including HTML (Hypertext Markup language), JavaScript, JQuery and AJAX are used on the client side. Cesium virtual globe has been exploited to display the data model and the calculated route.
To evaluate the introduced methodology and designed service, a three floor house with CityGML format in LOD4 was used as the case study. Generally, a client can request a 3D calculated path by selecting the source and destination points on the client browser. The server receives the request and returns the response as a 3D line to the client browser on the Cesium environment. In addition, a descriptive graphical user interface for visual inception of the route is offered to the users on their browser.
One of the advantages of the designed web application is that, the service is implemented on the browser. Hence, all devices equipped with a browser have possibility to run the 3D routing service. Besides the mentioned cross-platform capability, average expectation time of the graphical interface loading, data module processing and path finder module are 7.03 milliseconds, 12.42 seconds and 2.44 seconds respectively that visits a valuable criteria in emergency situations like an earthquake phenomenon. Regarding this fact that CityGML is a new data model and supported by a few software, the introduced architecture causes less implementation costs as well as automation of these systems.
Keywords: 3D indoor navigation, web application, interior space of buildings
Dr Hassan Lashkari, Miss Neda Esfandiari,
Volume 7, Issue 2 (8-2020)
Volume 7, Issue 2 (8-2020)
Abstract
Identification and synoptic analysis of the highest precipitation linked to ARs in Iran
Abstract
Atmospheric rivers (ARs) are long-narrow, concentrated structures of water vapour flux associated with extreme rainfall and floods. Accordingly, the arid and semi-arid regions are more vulnerable to this phenomenon. Therefore, this study identifies and introduces the highest precipitation occurred during the presence of ARs from November to April (2007-2018). The study also attempted to demonstrate the importance of ARs in extreme precipitation, influenced areas and identifies the effective synoptic factors. To this end, integrated water vapour transport data were used to identify ARs, and documented thresholds applied. AR event dates were investigated by their daily precipitation, and eventually, ten of the highest precipitation events (equivalent to the 95th percentile of maximum precipitation) associated with ARs were introduced and analyzed. The results showed that most ARs associated with extreme precipitation directly or indirectly originated from the southern warm seas. So the Red Sea, the Gulf of Aden and the Horn of Africa were the major source of ARs at the time of maximum IVT occurred. Synoptically, seven AR events formed from the low-pressure Sudanese system and three events from integration systems. The subtropical jet was the dominant dynamic of the upper troposphere, which helped to develop and constant of ARs. Moreover, the predominant structure of jets had a meridional tendency in Sudanese systems, while it was a zonal orientation in integration systems. The intense convective flows have caused extreme precipitation due to the dominance of strong upstream flow besides having the highest moisture flux. The station had the highest precipitation has been located in the eastern and northwestern region of the negative omega field or upstream flows.
Keywords: Identification and synoptic analysis, highest precipitation, Ars, Iran.
Iraj Ghasemi, Fatemeh Razzzaghi Borkhani, Mohammad Ali Mohammadi Gharehghani, ,
Volume 7, Issue 2 (8-2020)
Volume 7, Issue 2 (8-2020)
Abstract
Natural disasters and rural displacement: contexts and consequences in Balouch Abad village
Abstract
Every year, a number of rural settlements are affected by natural disasters or human factors, in such a way that life in these settlements is dangerous, and even, in some cases impossible. Thus, displacement programs in the form of leaving the main settlement and creating new settlements in another place will be considered by planners and managers. These programs are not without consequences and affect different aspects of the residents' lives. Identifying these consequences can provide sufficient experience and evidence for managing other displacement projects. Accordingly, the current study focuses on displacement phenomenon in Balouch Abad village in order to identify the consequences of displacement by discovering the contexts of displacement and explaining the residents' perception about the causes of this phenomenon. In general, empirical literature on the topic shows that the consequences of displacement, both positive and negative, occur in all dimensions of human life, and that a change in any dimension can change other aspects of the life of the target community. Investigating all dimensions of displacement has been considered in a few studies, in which less attention has been paid to the existing contexts, perceptions and planning and management structures. Therefore, this study contributes to the relevant literature by querying these contexts and providing solutions for displacement programs in the future.
The aim of this study is to understand the perception of the residents of Baloch Abad village about the causes and consequences of residential displacement using a critical ethnographic approach. This approach is suitable for studying phenomena such as residential relocation, which are the result of the decisions of the planning system and in most cases is faced with the unwillingness and lack of interest of stakeholders (residents). In fact, the critical ethnographic approach seeks to examine inequality, conflict, and power in a subculture. Thus, the process of displacement due to integration with a kind of conflict between residents’ willingness and the planning system, can be well explained using this approach. Data was collected using in-depth interviewing, non-participant observation, and focus group techniques.
The experience of displacement in Balouch Abad village indicated that the consequences of displacement do not occur independently and are correlated with each other. In other words, the negative consequences in terms of social and economic are rooted in the physical- consequences, and on the other hand, the social consequences are also rooted in economic consequences. On this basis, the lack of attention to the proportion of housing based on social relations has been the prelude to occur other negative consequences. The mismatch between the structure and size of dwellings and their occupational requirements (animal husbandry) has led to the collapse of subsistence foundations. Evidence also showed that maintaining neighborly relations in the village was influenced by the physical structure and system of land transfer. As a result, it can be stated that the various consequences of residential displacement can occur through planning and physical management. This study is based solely on the evidence, contexts and perceptions of key stakeholders who are residents of Balouch Abad village; however, the part of the challenges of displacement in this village is due to managerial actions that were not considered in this study. Therefore, it seems that mere focus on the view of stakeholders is one of the main limitations of this study, which is necessary to pay attention to this limitation. In this regard, it has been tried to provide sufficient evidence on manures of management the displacement process through the technique of triangulation. Future studies may take into account the views of both experts and stakeholders at the same time.
Keywords: Residential displacement, Balouch Abad village, natural disaster, contexts and consequences of displacement.
Zeinab Mojarad, Javad Jamalabadi, Najmeh Shafiei, Mohammad َali Zanganeh Asadi, Kobra Parak,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
Mass movements are among the morphodynamic phenomena that are affected by various factors at the level of the mountainous slopes. Massive movements and instability of the range are important hazards for human activities. Which often leads to the loss of economic resources and damage to property and facilities. These issues highlight the need for zoning the risk of mass movements as the first step in the proper environmental management of this phenomenon. In this research, we investigate the risk zone of mass movements using information estimation and surface density methods in the Watershed--ghochan-Shirvan Basin. For this purpose, at first, 12 important information layers affecting mass movements such as lithology, slope, elevation, rainfall, tide, erosion, climate, distance from the road, distance from fault, distance from the river, soil and land use, and digital They were. From the combination of operating maps with land surveys, the percentage of landslides in different units of each map was obtained. By calculating surface density, the information value of each factor was determined. Finally, a landslide risk zoning map was prepared by integrating different weight weights into two different information weighing models and a surface density model. The results of this study show that the southwestern part of the basin has the highest amount of landslide. Lithology is the most important element in the occurrence of landslides in the range. The surface density model is worth more than 12%.
Hamed Haidari, Dariush Yarahmadi , Mostafa Karampour,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
Dust phenomenon is one of the climatic fronts that is often formed in the dry and desert regions of the world, and is known as a natural hazard. Occurrence of walnuts causes dust, damage to the environment and the occurrence and exacerbation of respiratory, cardiac, air traffic and threats of tourism, agriculture and so on. Also, in the health section of the compounds in calcium dust, more than 2.5 g of it causes the appearance of kidney stones, and blood vessels. Iron causes swelling of the conjunctiva and retinal inflammation, as well as the syndrome. Magnesium causes depression, depression and dizziness of the individual. Short-term breathing of aluminum leads to coughing and irritation of the lungs and prolonged breathing causes damage to the lungs. In recent years, the identification of dust source areas has attracted the attention of researchers in numerous studies, and have introduced various areas around the world as the main source of generous production. The country of Iran, and in particular the Western and Southwestern logic of Iran, is constantly experiencing the phenomenon of dust and its problems. In the west of Iran, desert areas are located in the deserts of southern Iraq, Saudi Arabia and far away from Syria and North Africa. The geographic location of the southwestern part of Iran and its proximity to these deserts have led to a frequent occurrence of the phenomenon of dwarfs, which are different throughout the year.
In this research, two categories of data were used: the first group is data on climatic elements or unstable elements.
The annual climatic layers of the region were used for a 30-year statistical period of 2016- 2016. Measurement data on the temperature of surface temperature was obtained from a MODIS sensor in a 17-year statistical period (2000-2016). The second group of data layers and information on the ground factors or factors were stable. The layers of these variables included:
In this research, two categories of data were used: the first group is data on climatic elements or unstable elements.
The annual climatic layers of the region were used for a 30-year statistical period of 2016- 2016. Measurement data on the temperature of surface temperature was obtained from a MODIS sensor in a 17-year statistical period (2000-2016). The second group of data layers and information on the ground factors or factors were stable. The layers of these variables included:
- The digital elevation layer of the area with a precision spacing of 30 meters from this layer was used as the elevation layer of the area.
2. The slope of the region, in percent, which is the layer derivative of the digital elevation model and derived from the same specifications of the DEM layer.
3. The surface layer of the surface layer that was taken from the MODIS surface coating product
4. Layer of vegetation on the surface of the earth, which was also taken from the 1 kilogram MODIS vegetation cover
5. Soil layer that was prepared by the country's water and soil organization
The method of conducting analytical and statistical research in which the main objective is the determination of areas conducive to the formation or expansion of dust cores. In this regard, the establishment of land-based and climate databases is the first stage of work, after forming the required databases, the formation of information layers These data are in the GIS environment. In order to form these layers, the interpolated models in GIS were used and the optimal model was selected in such a way that less error values were obtained. After forming the existing layers, we classified and weighed each layer based on the AHP weighting algorithm. Finally, due to the assigned weights, the overlaying of the weights of the layers in the GIS environment was obtained and finally a potential capability map of the formation of local dust collectors in Lorestan province was obtained.
The rainfall factor is the most important and most important factor in determining the areas susceptible to becoming dusty. The weight of this factor in determining and identifying areas susceptible to dusty cores was equal to 239%. Vegetation factor, which was prepared using the NDVI indicator of the MODIS product, was the second factor in the development of dust-prone areas with a weight of 199.99. Relative humidity factor is the third factor or component that influences the determination of suitable areas to become the local focus of dust. The weight of this factor is equal to 0.15. The wind speed factor is in the fourth place in terms of determining the areas susceptible to dust. The relative weight of this factor is estimated at 116.0. As shown in Table 14, slope and elevation factors are the least important factors that can play a role in the production and development of dusty centers. The weight of these factors in identifying areas susceptible to formation of dusts is 0.024 and 032.2, 0 is detected. The calculated incompatibility index for this weighing is as high as 4.8, as shown in Table 15, which indicates that the contradiction between the offered weights of indices relative to each other is less than the allowed threshold (12).
Neutbay expressed the highest concentration of areas susceptible to dust mites in the eastern region, especially the northeast of the province, which includes the cities of Azna and Aligudarz. There are also parts of this category in the southern regions of the study area, including the cities of Poldokhtar and Rumshagan. In the central regions of the province as well as in the northwest of the province including the Khorramabad, Delfan, Dynasty and Dorood districts this class is not observed. In the southern parts of the city of Kohdasht, small parts of the floor of the potential centers of dust are also observed. This flooring has the most risk of becoming a dusty focus. The power source of many of the province's dusty incidents can also be said to be areas where some of them are currently potential sources of dust. Since they have played a major role in the identification and detection of these areas, rainfall and vegetation cover, these areas are exactly in line with parts of the province, which, firstly, have a mean rainfall of less than 250 mm, and the density of vegetation is less than 2 / 0 (NDVI index), which represents a very poor vegetation and, in fact, a lack of viable vegetation. In terms of land use, these areas, or inferior land, or very rangelands, are very weak.
The rainfall factor is the most important and most important factor in determining the areas susceptible to becoming dusty. The weight of this factor in determining and identifying areas susceptible to dusty cores was equal to 239%. Vegetation factor, which was prepared using the NDVI indicator of the MODIS product, was the second factor in the development of dust-prone areas with a weight of 199.99. Relative humidity factor is the third factor or component that influences the determination of suitable areas to become the local focus of dust. The weight of this factor is equal to 0.15. The wind speed factor is in the fourth place in terms of determining the areas susceptible to dust. The relative weight of this factor is estimated at 116.0. As shown in Table 14, slope and elevation factors are the least important factors that can play a role in the production and development of dusty centers. The weight of these factors in identifying areas susceptible to formation of dusts is 0.024 and 032.2, 0 is detected. The calculated incompatibility index for this weighing is as high as 4.8, as shown in Table 15, which indicates that the contradiction between the offered weights of indices relative to each other is less than the allowed threshold (12).
Neutbay expressed the highest concentration of areas susceptible to dust mites in the eastern region, especially the northeast of the province, which includes the cities of Azna and Aligudarz. There are also parts of this category in the southern regions of the study area, including the cities of Poldokhtar and Rumshagan. In the central regions of the province as well as in the northwest of the province including the Khorramabad, Delfan, Dynasty and Dorood districts this class is not observed. In the southern parts of the city of Kohdasht, small parts of the floor of the potential centers of dust are also observed. This flooring has the most risk of becoming a dusty focus. The power source of many of the province's dusty incidents can also be said to be areas where some of them are currently potential sources of dust. Since they have played a major role in the identification and detection of these areas, rainfall and vegetation cover, these areas are exactly in line with parts of the province, which, firstly, have a mean rainfall of less than 250 mm, and the density of vegetation is less than 2 / 0 (NDVI index), which represents a very poor vegetation and, in fact, a lack of viable vegetation. In terms of land use, these areas, or inferior land, or very rangelands, are very weak.
Parisa Jaberi, Samaneh Sabetghadam, Sarmad Ghader,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
Visibility is one of the most important optical characteristics of the atmosphere. Prediction of visibility is essential for air pollution, air traffic, flight safety, road traffic and shipping. Visibility reduction may be caused by different reasons. Fog is one of the most common reasons of visibility reduction, i.e. the droplets of water suspended in the atmosphere reduce the visibility to less than 1 km. Precipitation may also reduce visibility. Prediction of visibility in NWP models is usually accomplished by using the relationship between visibility and liquid water content, temperature, relative humidity. Purpose of the present work is to predict visibility during fog and precipitation over Tehran area in January 11th, 2014 and March 7th, 2013. Different algorithms including UPP1, AFWA, FSL and SW99 have been experimented to predict visibility.. Predicted visibility has been compared to observations, including Synoptic and METAR data in Imam Khomeini and Mehrabad airport. The WRF version 3.8.1 has been used to simulate precipitation and fog. In this simulation model configuration defined in Lambert uniform space. The model consist three nested domains. First domain was a 27-km grid model (83×65), surrounding a 9-km grid model (112×94) which was surrounding a 3-km grid model (112×97). Center of all domains was at longitude 51° and 44' and latitude 36° and 5' which is located almost at center of Tehran. All domains had 40 vertical layers and model top was located at 100hPa. The out puts of 3-km domain is used for visibility estimation. Initial and boundary conditions were set by using FNL data which is 1°×1° degree grid data. This data is available every 6 hours. Simulations were in 36 hours and first 12 hours was the spin up time. Results show that most of these algorithms can partly predict visibility reduction. The FSL algorithm works better than the other methods in fog situation and SW99 works better in snow situation. Comparing results shows that the visibility reduction during snow is more reliable than during fog. There were some errors in model predictions some of them were due to visibility algorithms, because the coefficients of these algorithms were driven in other parts of earth. The other errors were systematic errors of WRF. Predictions of temperature had warm bias and also there were positive bias in prediction of relative humidity.
Roghayeh Jahdi, Ali Asghar Darvishsefat, Hossein Badripour,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
Wildfires have proven to cause considerable damage to natural environments in Ardabil in the last years, and the prevalence of such events is anticipated to increase in the future. Fine scale wildfire exposure and risk maps are fundamental to landscape managers and policy makers for prevention, mitigation and monitoring strategies. In this paper, we provided 100 m resolution wildfire risk and exposure metric raster grids for the fire-prone municipalities in South Ardabil province corresponding to a fire simulation modeling and a geospatial analysis with a geographic information system, along with complementary historic ignition and fire area data (2005-2018). Fire risk parameters (burn probability (BP), conditional flame length (CFL) and fire size (FS)) were generated with FlamMap Minimum Travel Time (MTT) algorithm considering fire weather conditions during the last 14 wildfire seasons. Moreover, we estimated fire potential index (FPI) to spatially analyze where large fires likely initiate. Average BP, CFL and FS ranged from 0.00007 to 0.0025, 0.05 to 1.6 m, and 54.7 to 360.3 ha, respectively, that highlighted a large variation in the fire exposure factors in the study area. The calculated FPI showed two major areas with the highest values, where historic ignitions were high, and where large areas of faster burning fuels were present. The results of this study can be useful for analyzing potential wildfire risk and effects at landscape scale, evaluating historical changes and future trends in wildfire exposure, as well as for determining fuel treatment strategies to mitigate wildland fire risk.
Alireza Pilpayeh, Davoud Najafian Ghojehbiglou, Tofigh Saadi, Akbar Rahmati,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
Drought is one of the natural disasters occurring over a long period of time compared to other natural phenomena which intermittently impedes human societies through the negative impacts on water and agricultural resources and subsequently the economy. One of the methods of drought monitoring is the use of drought indices such as SPI. In this study, SPI index was used to study drought over the period 2001 to 2016. The SPI index is purely based on precipitation, so it is important to select a proper precipitation source to extract the SPI index at different time scales. Synoptic stations, due to lack of proper distribution and high statistical gaps, cannot be a reliable source of precipitation in this type of research, so global precipitation datasets having high spatial and temporal resolution can be used as a viable alternative to ground stations, in this study the Era-interim precipitation product, which is the product of the European Center for Medium range Weather Forecast was used. Initial results indicated that the Era-interim precipitation product could be used as a viable alternative to synoptic stations nationwide. Therefore, this precipitation product was used to assess the drought situation in the country. The study of drought status with respect to SPI indicated that with increasing SPI time scale dry and wet conditions became more severe so that mild dry and wet conditions in most in most month and years turned into severe dry and wet conditions.
Kamal Omidvar, Mehdi Mahmodabadi, Parisa Shams, Mahbobeh Amiri Esfandegheh,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
Due to the fact that the mechanism of anticyclone Movements is the desire to descend and suppress the air, so the effect of these movements and their location in the occurrence of flood falls is significant. For this purpose, in this paper, flood precipitation in the last two decades of Kerman province was studied and two of the most severe ones were selected. Due to the emphasis of this paper on the province of Kerman, the heavy rainfall was calculated for each station in the province using the Gumble Type 1 Distribution Statistical Index. Then, the thermodynamic properties of the precipitation were analyzed using radial data and Kerman station's sketch diagram. For analysis of these floods, daily rainfall data of the synoptic station 10 of the province and sea surface pressure maps and850,500,300 hectopascal levels were used. Then, the arrangement of the simulated pattern and its trend in the air maps, were studied during a selective period daily3. The results of the study indicate that the main cause of flood precipitation in the study area is to strengthen the eastern Mediterranean landfall in the middle troposphere, so when moved downward to the bottom of the polar system, it is transmitted to lower latitudes As a result, Western systems, with their movements on the southern warm waters, have a high moisture content and cause heavy rainfall in the region. Also noteworthy in the occurrence of precipitation is the presence of intense swinging movements on the southern waters, especially the Oman Sea, which causes more humidity to be injected into the interior areas of the country and provides the conditions necessary for the occurrence of such rainfall.
Ali Mehrabi,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
Based on the correlation diagram between the master and slave images (Fig. 5), the pair of appropriate images in terms of the shortest spatial and temporal lines is identified to produce the interferogram. As shown in Fig. 5, the maximum vertical baseline is obtained between -400 and -400. The obtained interferograms indicate the cumulative phase of the study area, which fluctuates between zero and 2ᴫ. Using StaMPS method on interferograms, 650 points were identified and selected as permanent scatter points in the study area. As can be seen in Figure 7, the cumulative displacement of the permanent dispersant points varies from + 45 mm to -45 mm. The displacements occur in the direction of the satellitechr('39')s view so that the positive numbers Indicates surface approach to satellite and the uplift and the negative numbers indicate the surfacechr('39')s distance from the satellite and the subsidence. As shown in the figure, in the western part of the mine wall, areas of 100,000 square meters have been heavily subsided. The next area, which has high subsidence points, is in the eastern part of the mine wall with an area of 68,000 square meters. The third area is located in the northwestern part of the mine with an area of 17,000 square meters.
By measuring the amount of displacement of Persist Scatters points, the altitude changes occurred in the mining area. Based on the results, the altitude variation changes in the range of 45 mm to -45 mm per year. Accordingly, 3 subsidence area were identified in western, eastern and northwestern parts of the mine wall with an area of 100, 68, and 17 thousand square meters. Considering the importance of the subject and in order to prevent the destruction of the mine wall, more precise geotechnical studies are needed in these specified areas.
By measuring the amount of displacement of Persist Scatters points, the altitude changes occurred in the mining area. Based on the results, the altitude variation changes in the range of 45 mm to -45 mm per year. Accordingly, 3 subsidence area were identified in western, eastern and northwestern parts of the mine wall with an area of 100, 68, and 17 thousand square meters. Considering the importance of the subject and in order to prevent the destruction of the mine wall, more precise geotechnical studies are needed in these specified areas.
Reza Bayat, Mahmood Arabkhedri, Najmeh Behnam, Zahra Gerami,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
Soil erosion is one of the most important environmental issues in developing countries, including Iran that there is inaccurate information about its amount and distribution. For this purpose, the accuracy and distribution of erosion classes obtained from EPM and MPSIAC models as compared to BLM as ground truth values were evaluated in Shahriari watershed. First, the required data and information for MPSIAC, EPM and BLM models for basin erosion status was stored in a database. Then, using ARC/GIS9.3 software, erosion class maps were prepared based on each model formula and they have been intersected with the ground-truth map. Also a point map containing 1400 random points was also prepared for sampling the maps obtained from the models. Then, based on random sampling points map, each of the statistical indices of RMSE, RRMSE, MAE, MBE, NSE, CD, CRM and MSE were calculated. Also, to verify the spatial accuracy of the erosion class maps derived from the error matrix models and the Kappa coefficient of agreement, overall accuracy, producer accuracy and user accuracy. The results of the erosion of the models showed that the mean erosion intensity in MPSIAC model was 589 and in EPM model 287 m3/ km2.year that the basin erosion status is estimated to be moderate for the basin with the help of MPSIAC model and EPM model. The analysis of the above statistical indices shows that the RSME, MAE, MBE and MSE statistics in MPSIAC model have lower values. As a result, the MPSIAC model has less error than the EPM model. Overall, the results of the statistical indices showed that the MPSIAC model's erosion classes were more in line with the BLM output (as a ground truth map) than the EPM model. Also the kappa coefficient in MPSIAC is higher than in EPM model. Overall, the results show that the MPSIAC model erosion class maps overlap with the BLM model and in fact with the actual conditions of the area.
Zeynab Basiry, Noredin Rostami, Dr. Amin Saleh Pour Jam,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
The main purpose of the research is the identification and prioritization of criteria and indicators affecting on lack of sustainable participation of rural communities in combating desertification plans in Dehloran, Ilam province. To determine the number of sample villagers, 189 family were selected using the Cochran formula. In this research, after determining the effective indices and also indicators in the lack of sustainable participation, the questionnaire was designed and its validity was determined by the relevant experts. The reliability of the questionnaire was also tested and validated by calculating the Cronbach's alpha coefficient. Data were analyzed using AHP and Friedman nonparametric test. The findings of the research show that the results of prioritizing the indicators that affect the lack of stakeholder participation in the AHP based combating desertification plans from the experts' point of view, design-implementation, and educational-promotional criteria are the maximum and minimum priorities, respectively. The results of criteria ranking using the Friedman test in terms of rural residents also indicated that the economic criterion is placed in the first priority and design-implementation, social criterion and educational-promotional are in the next priorities, respectively. Likewise, the results of effective indicators ranking in the lack of sustainable participation of rural communities in combating desertification plans based on the Friedman test in term of the experts’ viewpoints indicate that “ignoring people's income as a direct incentive to implement combating desertification projects” are the most significant economic indicator. Similarly, in the compartment of executive design indicator, from the experts’ viewpoint “the lack of a comprehensive participatory management program to combating desertification” and from the viewpoint of residents of the village “the lack of attention to popular opinion in the design and development of projects are prioritized as the most important indicators. In prioritizing social indicators from the viewpoint of the experts “dependence of the villagers on the state power, distrust of the results of combating desertification plans as well as low literacy level” and in terms of villagers’ opinions, “distrust of the results of combating desertification plans, the dependence of rural residents on the state power, migration of youth” are introduced and prioritized as the most substantial indicators. In the educational-promotional criterion, in terms of both views “lack of training the residents of the area regarding combating desertification projects and the related purposes, as well as lack of utilizing the local promotional group”, are determined as the main important indicators.
Khabat Derafshi,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
In this study, the risk map as an index to define the said complexity was prepared in 5 categories of risk by combination of Tehran metropolis flood hazard and vulnerability maps. To analyze the risk varieties, the hydrological catchments of Tehran were extracted by Arc Hydro model and 12 catchments were selected. Using land use, roads network, and the percentage of residential floor area, bridges, altitude, slope and drainage density variables, the flood hazard map was calculated. Dilapidated urban blocks, population density, land use, bridges, slope and drainage density layers were used as variables which affecting the flood vulnerability. Covariance index was applied for matched variables and considering the locational coherence between the values of them. Based on the new raster layers, flood risk variability in Tehran metropolis as well as in each of the catchments were analyzed using stepwise regression model. Explanation of locational changes of risk between the catchments needs to calculate the weighted average risk and the independent variables in 12 catchments that obtained by zonal statistics. Based on these average values the factor analysis used to determine the varifactors or main components of the variability in flood risk between the catchments. Finally, fractal geometry models (perimeter-area and cumulative number-area) were used to demonstrate the chaos of the flood risk value in 5 categories of risk. According to the flood hazard zoning map of Tehran metropolitan area, the extent of high hazard zone is 129.6 square kilometers. High risk zone covers 28.6% of Tehranchr('39')s area, indicating that most of the citychr('39')s extents (174.4 square kilometers) are located in the high flood risk zone. After that, the moderate hazard zone is 28.5% of the city area. Very low zones with 3.53% of the total area are the smallest zones in the city, which are only 21.5 square kilometers. Overall, 78.3 percent of the total area of the city is located in the moderate to very high zones of flood hazard, reflecting Tehranchr('39')s challenge to flooding. The vulnerability map defines that 138 km2 of the Tehran city area is located in high and very high zones of the flood vulnerability. According to Tehran metropolitan flood risk zoning map, 163.1 km2 of Tehran city area is located in high risk zone which has the highest rate among flood risk categories in Tehran metropolis (26.9%).
Gholamreza Mohamadi, Dr Reza Borna, Dr Farideh Asadian,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
In the present study, the spatial-temporal analysis of the Arctic vortex and its role in the occurrence of heavy precipitation days in the Ghare-Su basin have been investigated. For this purpose, firstly, with the 95% percentile method, heavy precipitation days of the basin were extracted. Then, considering the pervasiveness condition, 79 days of heavy and pervasive precipitation days determined during the1979–2015. In the following considering the contour representative of the polar vortex in the geopotential height of 500 hPa maps, elevation maps of 500 hPa, the vortex position identified on each of the heavy precipitation days based on its maximum extent on the synoptic zone. Synoptic analysis of the temporal and spatial of Arctic vortex during the selection of heavy and pervasive precipitation days shows that the 4 patterns can be identified within 79 days of heavy precipitation days. The position and concentration of the vortex patterns in each season have changed. So that the least penetration of the vortex is seen during the autumn and the most penetration in the winter. In all cases of the days of heavy and pervasive precipitation due to the locating the trough of the arctic vortex over the study region, which coincides with the settlement of the huge Rex and Omega blockings on Europe. The highest correlation between the latitude of the vortex and the precipitation intensity is seen in the third pattern ( the Red Sea to the west of the Persian Gulf), which has the most vortex penetration in the region. In each of the vortex spatial locations, the location, length, and depth of the trough have also changed in each location. So that the best position and the most impact of vortex occurred in the third and fourth patterns where the troughs from vortex have the most depth and extension on adjacent water resources.
Farhad Azizpour, Vahid Riahi, Somayeh Azizi,
Volume 7, Issue 4 (2-2021)
Volume 7, Issue 4 (2-2021)
Abstract
Abstract
As information about disease and mortality grows, so do appropriate methods for analyzing this type of data that meet different needs. One of these methods is spatial analysis of the disease, which considers its geographical distribution along with other risk factors. The present study is an attempt to depict the spatial pattern of coronary heart disease distribution in rural settlements of Damavand and to explain the factors affecting the spatial distribution of this disease in the study area. Spatial analysis of corona prevalence using spatial statistics analysis methods can extract and analyze the spatial patterns governing the geographical distribution of this disease. For this purpose, the present study seeks to answer the following questions:
As information about disease and mortality grows, so do appropriate methods for analyzing this type of data that meet different needs. One of these methods is spatial analysis of the disease, which considers its geographical distribution along with other risk factors. The present study is an attempt to depict the spatial pattern of coronary heart disease distribution in rural settlements of Damavand and to explain the factors affecting the spatial distribution of this disease in the study area. Spatial analysis of corona prevalence using spatial statistics analysis methods can extract and analyze the spatial patterns governing the geographical distribution of this disease. For this purpose, the present study seeks to answer the following questions:
- What pattern does the spatial distribution of coronary heart disease in the rural area of Damavand city follow?
- What factors have influenced this spatial distribution pattern?
Due to the nature of the subject, the present study is of the combined type and in terms of applied results. The method of data collection is based on documentary-library and survey-field data. Initially, the statistics of the number of patients with coronary artery from the beginning of April 2020 to the end of July 2020 were collected by referring to Damavand health center. Then spatial analysis is applied to them. In order to study the spatial pattern of corona disease distribution and to recognize its non-random structure from various statistical indicators such as mean, percentage, hot spot analysis and also to properly understand the pattern of hot spot clusters by measuring directional geographical distribution (standard ellipse) in GIS software environment. Used. After describing the structure and pattern of dispersions, one should look for the cause and reasons of dispersions. Thus, in field surveys, after determining the number of patients with coronary artery disease, snowball interviews were conducted with 23 residents of Damavand city in order to identify and analyze the factors affecting the spatial distribution pattern of coronary heart disease in this city. After conducting the interviews and collecting the data, in order to analyze them, the underlying theory in the Maxiquida software environment was used. Pearson correlation coefficient was used to determine the relationship between the factors affecting the prevalence of the disease in the study area as independent variables with coronary heart disease as a dependent variable in SPSS environment. Then, Moran's spatial autocorrelation analysis model was used to know the type of distribution pattern of the identified factors.
This part of the findings is divided into two parts according to the questions raised in the research: Spatial distribution pattern of coronary heart disease in rural areas of Damavand city Out of a total of 67 villages, 21 rural points (31.34%) and 1 rural point (1.49%), respectively, have the lowest and highest number of patients with coronary heart disease. Based on the analysis of clusters of hot spots and elliptical curve of geographical distribution, most hot spots are located in the west and northwest of the city and the villages located in these spots with low health centers have almost high population density that are adjacent to each other and They are close to the cities and on the main road. Most of the cold spots are located in the east and southeast of the region.
Factors affecting the distribution pattern of coronary heart disease in rural areas of Damavand city After determining the spatial pattern of corona disease distribution in the rural area of Damavand city, the effective factors in the spatial distribution pattern of this disease should be identified and analyzed. These factors include: Weak official information on coronary heart disease; Weak local community attention to the principles of health exposure to corona risk; Simplifying the risk of coronary heart disease; Short geographical distance between settlements; High level of inter-residential interactions; Weakness in providing health services. Pearson correlation coefficient was used to determine the relationship between the factors affecting the prevalence of the disease in the study area as independent variables with coronary heart disease as a dependent
This part of the findings is divided into two parts according to the questions raised in the research: Spatial distribution pattern of coronary heart disease in rural areas of Damavand city Out of a total of 67 villages, 21 rural points (31.34%) and 1 rural point (1.49%), respectively, have the lowest and highest number of patients with coronary heart disease. Based on the analysis of clusters of hot spots and elliptical curve of geographical distribution, most hot spots are located in the west and northwest of the city and the villages located in these spots with low health centers have almost high population density that are adjacent to each other and They are close to the cities and on the main road. Most of the cold spots are located in the east and southeast of the region.
Factors affecting the distribution pattern of coronary heart disease in rural areas of Damavand city After determining the spatial pattern of corona disease distribution in the rural area of Damavand city, the effective factors in the spatial distribution pattern of this disease should be identified and analyzed. These factors include: Weak official information on coronary heart disease; Weak local community attention to the principles of health exposure to corona risk; Simplifying the risk of coronary heart disease; Short geographical distance between settlements; High level of inter-residential interactions; Weakness in providing health services. Pearson correlation coefficient was used to determine the relationship between the factors affecting the prevalence of the disease in the study area as independent variables with coronary heart disease as a dependent
Hossein Varjavand Naseri, Asghar Tahmasbi, Hasan Darabi, Ahmadreza Yavari, Mohammadjavad Amiri, Gholamreza Nabi Bid Hendi,
Volume 7, Issue 4 (2-2021)
Volume 7, Issue 4 (2-2021)
Abstract
Extended Abstract:
The increasing challenge of water in many regions of the country is rooted in inappropriate governance of water resources at the basin levels. Investigating the interactions of different stakeholders and institutional arrangement affecting it is one of the key elements of governance system. The most important obstacle to achieving the optimal governance model of water resources in developing countries is the unknown path from governmental management, to good governance. The analysis of stakeholders and influential entities on their interactions is considered as one of the important pillars of governance assessment frameworks.
Accordingly, the purpose of this study is to evaluate the water resources of Zayandeh roud basin from the perspective of interactions between actors and formal institutions affecting their interactions. In this regard, it is attempted to answer two main questions: firstly, what is the organizational structure in management of Zayandeh roud?, Second, how far are the organizations’ policies and programs involved in the management of the watershed ?
In this study, Isfahan, Chaharmahal - bakhtiari , Khuzestan and Yazd which are related to the river basin issues, were selected for social network analysis. Organizations and governmental and non- governmental institutions related to the process of sustainable management were questioned. In this regard, according to the numerous studies conducted in the field of Zayandeh roud and Gavkhoni wetland , the number of organizations and related institutions were identified. Then, the network matrix of actors’ policy and collaboration was formed and centrality indices of input and output grades and betweenness centrality indices were measured through Ucinet software.
There are a wide range of active actors in management of Zayandeh roud river basin, each in an attempt to obtain more water resources from this river. As mentioned in the conceptual framework of the research, two key aspects are investigated. Key stakeholders analysis and their role in water resource management and review of actors ' policies in water resource management in two dimensions of belief in changing policies, and the need to change policy from the viewpoint of other actors. Accordingly, the research findings are presented in the following parts.
Accordingly, the purpose of this study is to evaluate the water resources of Zayandeh roud basin from the perspective of interactions between actors and formal institutions affecting their interactions. In this regard, it is attempted to answer two main questions: firstly, what is the organizational structure in management of Zayandeh roud?, Second, how far are the organizations’ policies and programs involved in the management of the watershed ?
In this study, Isfahan, Chaharmahal - bakhtiari , Khuzestan and Yazd which are related to the river basin issues, were selected for social network analysis. Organizations and governmental and non- governmental institutions related to the process of sustainable management were questioned. In this regard, according to the numerous studies conducted in the field of Zayandeh roud and Gavkhoni wetland , the number of organizations and related institutions were identified. Then, the network matrix of actors’ policy and collaboration was formed and centrality indices of input and output grades and betweenness centrality indices were measured through Ucinet software.
There are a wide range of active actors in management of Zayandeh roud river basin, each in an attempt to obtain more water resources from this river. As mentioned in the conceptual framework of the research, two key aspects are investigated. Key stakeholders analysis and their role in water resource management and review of actors ' policies in water resource management in two dimensions of belief in changing policies, and the need to change policy from the viewpoint of other actors. Accordingly, the research findings are presented in the following parts.
- decision making and facilitating information flow
- Power and control of actors in the network of organizational collaboration
- Co - ordination role in the enterprise - cooperative network
The findings of this research show that in the dimension of capacity and flow of information watershed management, Regional water organization in Isfahan province and in the next rank of water resources management, Zayandeh roud coordination council and Isfahan provincial governor are organizations that have high output degree and can play a key role in information flow. In other words, information that is necessary for the actors and other organizations is better flowed by these organizations.
In terms of supervision on the network of interactions and control over other actors in the basin, which was measured with the degree of centrality of input, Isfahan parliament representatives in the first and the agriculture jihad of Isfahan province gained the highest rank respectively. After these organizations which are mainly government and dependent entities, non - governmental organizations of three other provinces have the lowest rank in terms of ability to control the network. The lower power of NGOs in the social network of the organization indicates a low planning system for the management of the watershed. Comparative studies in the river basin show that the feature of the extent and diversity in the social - ecological system of a watershed among several distinct political areas can reveal the importance of the position of organizations that have a bargaining power in the watershed management network.
Betweenness centrality index in information exchange network has a fundamental role. The actors with the intermediary rate and high control power among the organizational stakeholders are the same organizational entrepreneurs who have an important role in establishing relationships and increasing interactions among other actors. If the actors with high degree of mediation are removed from the network, information exchange in the network will be disrupted.
It is obvious that without knowing these corporate entrepreneurs or in other words, actors with high mediation ability in the exchange information network, any activity in the direction of comprehensive management of land and sustainable development will be associated with time and cost. In connection with the task of coordination in watershed management, the Jihad of agriculture organization, department of environment and water room committee of Isfahan have obtained the highest degree of betweenness centrality which seems to be a suitable place due to their organizational functions. In this regard, attention and reinforcement of organizations such as NGOs and parliament representatives of three other provinces and provincial governor of these three provinces with low degree of betweenness centrality can be suggested. The lack of such interaction is undoubtedly one of the challenges facing sustainable management of the region. According to the results of other studies, it can be said that to achieve sustainable and integrated management of land and preservation of natural areas, it is necessary to study the pattern of relationship between organizational stakeholders.
The results show that the Regional water organization of Isfahan province and the Zayandeh roud coordination council have a higher position in decision making and information flow. On the other hand, the high performers of water resources such as Iran’s water resources management company and the Zayandeh roud coordinating council and in the next level, Regional water organization, the provincial governor and the parliament representatives of Isfahan are the best critics of the watershed governance. In contrast policies of jihad agricultural organization, farmers and Regional water organization of Isfahan have been criticized by other actors.
In terms of supervision on the network of interactions and control over other actors in the basin, which was measured with the degree of centrality of input, Isfahan parliament representatives in the first and the agriculture jihad of Isfahan province gained the highest rank respectively. After these organizations which are mainly government and dependent entities, non - governmental organizations of three other provinces have the lowest rank in terms of ability to control the network. The lower power of NGOs in the social network of the organization indicates a low planning system for the management of the watershed. Comparative studies in the river basin show that the feature of the extent and diversity in the social - ecological system of a watershed among several distinct political areas can reveal the importance of the position of organizations that have a bargaining power in the watershed management network.
Betweenness centrality index in information exchange network has a fundamental role. The actors with the intermediary rate and high control power among the organizational stakeholders are the same organizational entrepreneurs who have an important role in establishing relationships and increasing interactions among other actors. If the actors with high degree of mediation are removed from the network, information exchange in the network will be disrupted.
It is obvious that without knowing these corporate entrepreneurs or in other words, actors with high mediation ability in the exchange information network, any activity in the direction of comprehensive management of land and sustainable development will be associated with time and cost. In connection with the task of coordination in watershed management, the Jihad of agriculture organization, department of environment and water room committee of Isfahan have obtained the highest degree of betweenness centrality which seems to be a suitable place due to their organizational functions. In this regard, attention and reinforcement of organizations such as NGOs and parliament representatives of three other provinces and provincial governor of these three provinces with low degree of betweenness centrality can be suggested. The lack of such interaction is undoubtedly one of the challenges facing sustainable management of the region. According to the results of other studies, it can be said that to achieve sustainable and integrated management of land and preservation of natural areas, it is necessary to study the pattern of relationship between organizational stakeholders.
The results show that the Regional water organization of Isfahan province and the Zayandeh roud coordination council have a higher position in decision making and information flow. On the other hand, the high performers of water resources such as Iran’s water resources management company and the Zayandeh roud coordinating council and in the next level, Regional water organization, the provincial governor and the parliament representatives of Isfahan are the best critics of the watershed governance. In contrast policies of jihad agricultural organization, farmers and Regional water organization of Isfahan have been criticized by other actors.
© 2026 CC BY-NC 4.0 | Journal of Spatial Analysis Environmental hazarts
Designed & Developed by : Yektaweb