Journal of Spatial Analysis

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Environmental hazards include all kinds of hazards in the environment such as natural and technological or natural and man-made. The natural phenomena such as rains or floods are the normal behaviors of the nature which only when they cause damage to the human life, are considered as hazard. The technological events such as road accidents, air pollution and chemical pesticides are always dangerous to human life. Both kinds of two hazards are produced in the context of human- nature relation. For example if human beings avoid flood prone areas there will be no harm or damage. And if human beings control their waste in the urban areas they will never pollute the city. Thus, this is the human who causes risk and damage to his life. The relation between human and the nature is governed by the thoughts and beliefs of human or in general terms his world perspective and philosophy. It is the human perspective and belief which controls his action at any circumstances. A person who believes in the nature as his mother and supporter of life differs from the one who thinks of nature as a sole source to use and enjoy. The first one gets only his basic needs from the environment, but the second person tries his best to exploit the nature for his benefits. Therefore to understand the intensity and frequency of environmental hazards, we should investigate the mental beliefs of people living in different places. A brief discussion of the historical development of hazards will help us to have a better understanding of the philosophical basis of the environmental hazards. From the ancient times up to around nineteenth century life was very simple and man had been using nature only for his basic needs, there was no consideration of environmental hazards. Hazards were considered only as diseases threatening the human life. But later, especially after the industrial revolution, due to the increase of human population and demands, the use of natural resources was exponentially increased far above the production and recovery of the nature. This process triggered the occurrence and expansion of environmental hazards.  The human- nature relation is studied by different scientific fields such ecology, anthropology, and geography from different aspects. The ecologists mostly emphasize on the relationship of individuals with his environment, as the characteristics of environment controls his life. While geography studies the spatial relations between human population and environmental assets. As a result, the philosophical stances of these fields differ substantially. Ecologists want to see whether this relation is dominated by the needs and intentions of man or by the capacity and potentials of the nature. From this point of view three kinds of philosophies were developed including anthropocentrism, biocentrism and ecocentrism. On the other side, geography emphasizes on the spatial distribution of human population on the basis of environmental resources. This spatial relation between human and natural resources is believed to be controlled by the nature or human conducing to the development of two philosophies of environmental determinism and possiblism. Ecological philosophy of anthropocentrism was dominated in the earlier centuries, focusing on the will of human to use and enjoy the nature. In this view, the nature has the instrumental value for human. The result of this philosophy was depletion and destruction of the environment in favor of the human development. But during the twentieth century some philosophers stated that the human does not have the right to harm and damage all living creatures including animals and plants. This view ended with the biocentrism approach.  During the second half of the 20^th century due to the over exploitation of nature by human, the philosophers and ecologists realized that the human kind in order to possess a sustainable living should not harm any members of the environmental system including even rocks, rivers, soil and etc. This approach developed the ecocentrism philosophy. The main controlling force in these philosophies is the ethical stance of humans. On the other hand, the older geographers believed that it is the nature that controls the human distribution and living conditions. The humans cannot change the natural arrangement of the environment and should limit their activities to the natural allowances. The development of the technology after the Second World War changed this view. Some geographers believed that human can change the environment by his techniques and developed the possiblism. The adoption of this philosophy and the growth of industrial development ended with the deployment and damage of the natural resources. It is clear from the aforementioned discussion that in all cases, the main reason for the depletion and destroy of the environment was lack of ethical considerations in human behavior toward the nature. If the ecologists have come with the ecocentrism, geographers developed the geocentrism philosophy. That is, to save the nature and prevent environmental hazards we, as human beings, should preserve the natural arrangement of resources. We should not disrupt the spatial order of any resources, because it will cause harmful results in the environment. For example eroding the soil will deteriorate the vegetation and cause floods and other hazards. The alteration of spatial order of surface temperature has caused the thermal imbalance and hence global disorder and warming. There is no doubt that the relation of each human should be controlled and put in the moral contexts, but to prevent the environmental hazards an overall effort is needed over the environment which is possible only through the preservation of spatial order of natural resources. Spatial management of land resources is the outstanding example of this philosophy and ethic.

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Although environmental hazards occur because of natural factors, however, political economy, controlling the sociospatial relations and conditions, also affect centrally the increase or decrease of physical and social vulnerability caused by hazards. In this regard, present paper has put the spotlight on “explaining the role of spatial distribution of social stratification in vulnerability to environmental hazards in the city of Tehran”. This is based on Political Ecology Approach which emphasizes the domination of prosperous social strata on the urban natural-ecological endowments and utilities and marginalizes low-income and inferior social strata. So, the recognition of social strata inhabitation across the city is significant for the analysis of social inequalities and their effects on the vulnerability of environmental and human hazards. The concentration of middle to high class and working and inferior classes has also caused the range of social inequality to increase in the metropolitan of Tehran and this trend per se has transformed Tehran to the spatial reflection of the contrast between poverty and wealth to the greatest extent in the country. Hence, regarding the fundamental role of social stratification and class structure and its evolution in explaining the dynamics of socio-economical relations in the dominant society and the process of urban space production and reproduction, explaining the role of spatial distribution of social stratification in vulnerability to environmental hazards in the city of Tehran is significant and necessary. Vulnerability to environmental hazards has been studied from the physical, biological perspectives, social construction perspective and contingency perspective. The present paper emphasizes the effects of social construction on the production of vulnerability. Scientists think radical and critical geography of space is a kind of social production. They believe that not only urban space, but also the entire space has a social structure and nobody can analyze it thoroughly regardless to the society’s work on the space. Thus in a world under the Capitalist System, urban space represents a reflection of the control and domination of superior social strata (owners of power, wealth and high status, or the owners of political, economic and socio-cultural assets) in its functional zones.  This has been appeared in the recent decades, within the literature of hazards and catastrophes and based on “an approach of vulnerability” which has been rested on Political Ecology. The mentioned approach has been concentrated on a series of socio-spatial conditions and political economy which shapes the hazards and catastrophes. Some of the effective social conditions in shaping the hazards and catastrophes and their amounts of vulnerability depend on the racial, ethnic and class characteristics. Racial, class, ethnic and political economy analyses, which dominate their social ties, are considered as part of understanding knowledge system of hazards and catastrophes. Since this causes detecting the role of political economy of inequalities and racial, class and ethical processes and the marginalization caused by it, in the emergence of hazards and exacerbation of catastrophes and crises impacts. To use job structure means to emphasize concrete class structures, according to which an image of social inequality can be offered. Thus in present study, for structure determination and main composition of social stratification in Iran and Tehran “Structure Determination and Composition of Social Strata Model” was used. According to this model and with the use of data from matrix tables, major occupational groups and occupational situation have been classified in 5 classes superior strata, traditional middle strata, new middle strata, working and inferior strata and farmers. The data were prepared and analyzed by ArcGIS and Ms Excel softwaares.   During the last century, uneven development process of the country was in favor of the Tehran and superior strata and powerful institutions located in this city. Regarding the processes and relations emerged from political economy of space and political ecology of Tehran, social strata inhabitation of Tehran has been in compliance with environmental capacities raised from topographic and microclimatic distinctions and ecological endowments. The findings of present paper also indicate physical and social vulnerability changes caused by probable hazards related to the general pattern of social strata inhabitation in north-south geographical direction. Spatial distribution of populated blocks in 1996, for which more than 30% of their inhabitants were “senior managers and experts” and “manufacturing jobs employees and laborers”, indicates the above mentioned issue and clearly show the poverty (old poor neighborhoods) and wealth (expensive and rich neighborhoods) spatial centers. In addition, according to the supporting studies on Tehran Comprehensive Plan, most of old urban tissues are in central and southern regions. Also according to the International Seismological Research Agency (JICA), the mentioned regions would be the most vulnerable in the Tehran probable earthquakes. Therefore, it can be said that findings and results of the present study indicate the determining place of political economy of space and urban political ecology and also the fundamental role of social stratification and class structure for recognition, analysis, explanation and understanding of the urban development challenges and problems. Hence, this is impossible to reduce social and physical vulnerabilities caused by natural and human hazards, particularly in the poor neighborhoods, regardless of political economy of space mechanisms and reduction of the gap and even urban development. 

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Spatial Analysis of Villagers’ Resilience Against Environmental Hazards
(A Case Study of Central District of Faruj County)
Statement of the problem
The concept of resilience is the outcome of changes in risk managing in current decade. Today, the views and theories of disaster management and sustainable development seek to create societies resilient against natural disasters. Natural disasters such as earthquakes, droughts, floods, etc. are inevitable phenomenon which always pose a serious threat to development, especially in rural areas. This reflects the need to pay more attention to resilience in local level (rural areas). Resilience is the ability of a social or ecological system to absorb and deal with disorder or disturbance, so that the basic functional structure, can maintain the capacity of reorganization and adapting to changes and tensions. Carpenter defines resilience as the capacity of an environmental and social system to absorb a disruption, reorganize and thereby maintain essential functions. Thus, in order to reduce damage caused by natural disasters, the capacity of rural areas to deal with these events should be increased. Increased level of resilience against natural hazards is possible through accurately identifying the factors affecting resilience. Therefore, the aim of this study is the spatial analysis of factors affecting the promotion of rural environmental resilience in the face of natural hazards in rural areas of Faruj County.
In fact, the present study seeks to answer the following questions: what are the factors which may increase the level of resilience in the sample communities exposed to natural hazards, and how resilient are the sample villages of the study?
Research Methodology
This study is an applied research conducted in a descriptive-analytical method based on questionnaires. Data were collected through library research and field works which required completing questionnaires and conducting interviews with villagers living in the Central District of Faruj County.
Validity of the questionnaires was confirmed based on experts' views and its reliability was calculated using Cronbach alpha for different dimensions. The population consisted of 4591 households from the villages suitable for temporary accommodation. Based on the Cochran formula, 252 were obtained from these samples. They were selected by stratified random sampling.
Using statistical analysis methods in SPSS software, we analyzed the data to measure resilience in sample villages of the study area. We also used Excel and GIS in various parts of the study. To determine the best option, we used the VIKOR models, Gray relational analysis and Additive Ratio Assessment (ARAS).
Results and discussion
The results showed that infrastructure dimension with a mean of 2.92 and the economic dimension with a mean of 2.58 respectively had the highest and least impact on increased resilience which suggest that these villages compared to sample villages have relatively good infrastructure facilities. However, due
to the lack of proper institutional framework and poor performance of crisis management institutions, villagers are less satisfied with these organizations. Accordingly, based on t-test, the actual mean of the total respondents’ views was less than 3 and at the moderate level, and the economic index with the t statistics of -10.38 had the most negative impact on the resilience of the villagers.
It should be noted that according to the results of the resilience correlation with the individual characteristics of the respondents, it became clear that the gender and marital status has a direct and weak relationship with each dimension of resilience, which means men and the married people compared to the women and the singles believe their villages are more resilient. Besides, there is a weak and reverse relationship between the education of the individuals and their resilience, meaning that people with lower education compared to educated people, believe their villages are more resilient. There was no relationship between age and the dimensions of resilience.
In order to assess the impact of each index of the study on the level of resilience in the villages of the study, the confirmatory factor analysis test was used which revealed that among the indices of the study, "the villagers’ satisfaction with the performance of the Rural Council and administers (Dehyars)", "the role of institutions in educating people about various incidents" and "the use of new and durable materials to prevent the damaging effects of the incidents" had the greatest effect on the resilience of the samples villages.
Eventually, to determine the best village in terms of resilience for establishing a temporary settlement site in crisis management, we use three techniques: additive ratio assessment (ARSA),- VIKOR and Gray relational analysis. We prioritized the villages based on the mean rank method. -Considering the indices of resilience in the rural areas of the study, the villages of Mefrangah, Ostad and Pirali have the highest ranks, and the villages of Rizeh and Roshavanlou have the lowest ranks.
Key words: resilience, environmental hazards, organizational-institutional dimension, additive ratio assessment (ARSA), Faruj Central District

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Land cover changes as a basic factor in environmental change act and has become a global threat. In this research, changes in land cover in rural tourism areas by neural networks, Markov chains in software ArcGIS, ENVI, Terrset using the TM and OLI satellite imagery, Landsat Satellite was surveyed for a period of 30 years for three periods of 1985, 2000, and 2015. The findings of the first stage show that land cover changes at the period 1985-2015, were classified in five class residential spaces, Commercial, Green, Empty and mountainous spaces and communication networks. In this study, the area of mountainous and empty spaces (13.25%) has decreased and in contrast, has decreased the amount of green spaces (6.221%), Residential (5.258%), commercial (1.264%) and communication networks (0.529%). Changing land cover as one of the most important environmental risks has been directly influenced by the Commodification phenomenon. Also, the findings of the prediction using the Markov-CA chain showed that with the continuation of the current and excessive loading on the ground, on the horizon of 2030, green cover (Agriculture, gardens and grassland, garden and residential)  and  wild land  and mountain cover have been reduced and to cover residential and commercial villas will be added. Based on research findings concluded that land cover changes in rural tourism areas in order to achieve more profits has become incompatible applications. This change in land cover, in addition to the economic, social impacts, has led to the formation of environmental hazards in the Bharang area. Developing tourism in the study area by removing agricultural land from the production cycle has led to an increase in urban activities and the formation of new activities (service, Residential Garden, residential villa) instead of traditional activities(agriculture and livestock) that are economical. And by loading too much ecological power tolerable land, while posing environmental hazards, causing incompatible activities next to each other, they do not match. Therefore, tourism, which gradually formed over the years and now it has become a part of rural texture, Spatial Conflict and heterogeneity two strains has created for them. Spatial Conflict created, due to changes in land cover and acceptance of incompatible activities that derive from human-nature relationships. This means that the rapid and unpredictable trend of tourism development, the rural landscape has encountered a problem and with changes in land cover, has led to inconsistencies between different activities and eventually has shaped the Spatial Conflict.
 

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Analysis and Measurement of Environmental Resilience of Villages in Gorganrud Watershed against Flood (Golestan province, Iran)
 
Abstract
Environmental hazards are inevitable phenomena that always place serious risks on the development of human societies, especially rural development. In the recent years, however, significant changes have been made in crisis management approaches, and the prevailing view has shifted from the "reduction of vulnerability" approach to "resilience improvement". Resilience is a new concept often used in the face of unknowns and uncertainties. Therefore, along with this change of attitude, it is important to examine and analyze natural hazards in terms of resilience. According to global statistics, floods, as one of the most devastating natural disasters, have caused the greatest losses and casualties to human settlements, which is true both in our country and in Golestan province. Investigations show that only in the statistical period of 1991-2014, 106 rainfall cases have led to the occurrence of floods in this province. These floods have damaged natural resources, the environment and the prevalence of environmental pollution; In addition, other natural and human factors have contributed to the heightened risk of flood damage. But if it was planned for the restoration of villages, then the damage could be reduced. Therefore, this research was conducted with the general purpose of determining the relationships between environmental factors and factors of rural communities of Gorganrud watershed on their resilience and numerical values. Finally, the residual spatial analysis of rural limited settlements was studied. Accordingly, the research questions are as follows: a) What is the relationship between environmental factors and factors in the villages of Gorganrud watershed in Golestan province with the resilience of the communities living in them in the face of flood? b) What are the resiliency values ​​of these communities in the environmental dimension and which zones? This is an applied research with descriptive-analytical method. A library of researcher-made questionnaires was used for collecting data using library resources. The statistical population consisted of 106 villages with 22,942 households. First, 31 villages were selected by cluster sampling. Then, using Cochran formula, 318 families were selected as sample size and selected by simple random sampling method. Also, for assessing the validity of the questionnaire, using Delphi collective wisdom methods, it was determined by using historical studies and opinions of experts in rural areas. The reliability of the questionnaires was also determined by using the Cronbach's alpha coefficient in the pre-test method. The value for the household questionnaire was r_a1=0.841 and r_a2=0.862, respectively. All steps for statistical analyzes have been performed by Excel and SPSS software. Additionally, the development of mapping, risk-taking, risk and resilience was also done with the help of ArcGIS software and the weight of each criterion was determined by the Super Decision tool; Then, using the weighted and linear overlapping methods, each of the sub-criteria of the main indexes was multiplied in its weights. The study area is divided into two distinct sections in terms of geological and geomorphological structure. The southern and eastern parts of it are the ripples of the eastern Alborz mountains, which are taller in the southern part and extend along the east-west direction. Also, the northern part of the studied basin is the Gorgan plain, in which the main branch of Gorganrud flows from east to west and all branches of the south and east are drained. Following the general slope of the main branch and its long-standing walls in the mid-east, it is usually not flooded; but as far as the west is concerned, its slope is very low and one of the flood plains is considered as the basin. The results of the research show that there is a significant relationship between the environmental factors of the studied basin villages and the resilience of the communities inhabited by them in the face of floods. Also, the average environmental resilience of the whole region was lower than the average (2.76 average), rural households in the sub-basins of TilAbad and ChehelChai with an average of 3.24 and 3 had relatively good environmental resilience, But most of the rural households in the sub-basins of Ghurechai and Lower of Gorganrud, Mohammad Abad-Zaringol, Madarsoo and Sarisoo, with an average of 2.89 to 1.85, had a poor environmental resilience. In addition, According to the flood risk resilience map, it can be said that of the total 31 sample villages studied, about 29 percent of sample villages have "medium upward" resilience in facing flood risks; conversely, most of these villages (71%) also have relatively low degree of resilience. Also, comparing the findings of this study with the results of most other researches, such as the studies of Olshansky and Kartes (1998) regarding the necessity of considering the environmental factors of settlements, observing the necessary environmental standards and the necessity of using proper land use management tools to reduce risk hazards and improve resilience, Center of Emergency Management Australia (2001) on the need to consider the state of the infrastructure, including the level of communications and accesses, biological conditions, including the status of pollution, as well as geographical characteristics, such as distances and proximity, climate, topography, as well as the general results of studies by Rafiean et al. (2012) in special selection of the most suitable model of resilience based on the combination of carter and socioeconomic model due to the simultaneous attention of this model to its geographical features and its comprehensiveness, as well as attention to the local communities' participation, Rezaei (2010), Shokri Firoozjah (2017) and Anabestani et al. (2017) Regarding the low value of the calculated population, the resiliency number of the society is consistent and consistent with the lack of attention to infrastructure issues, locations, etc., which is below the baseline (3). As a result, all of the aforementioned components of the resilience of inhabitants of sample societies have been affected by its environmental dimension, which is often due to insufficient attention and insufficient handling of them, which reduces resilience of rural residents to flood risks.
 
Keywords: Environmental hazards, Flood, Vulnerability, Resilience, Spatial analysis, Golestan Gorganrud basin.
 

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Abstract

Urban heat island (UHI) is one of the environmental phenomenon which has made difficult environmental conditions for citizen. This study aims to evaluate the spatial and locational variability of Esfahan urban heat island according to the role of land use. Thus an area about 190.2 square kilometers (km2) in Esfahan, as the microclimate, was studied. In order to analyze the relationship between land use and land cover changes on Esfahan urban heat island, the images of Landsat 7 (TM and ETM +) and Landsat 8 (OLI / TIRS) on 20 July 1989, 17 August 2005, 18 August 2014 have been used. The results show that the urban areas has experienced 31% changes in positive direction; while the agricultural sector and green space havehad a reduction of 25% in their area. The analysis of the intensity of heat island show that heated cores are related topoor and barren lands with about 37/33 and 36/5. Although the most area of thermal classwere related to warm thermal class in 1989 and 2005, the average thermal classes were about 63/8%in 2014. Moreover, the locational variation distribution of Esfahan heat island shows that the locationof the heat island has gradually changed. For example in 2014 it included small parts in the south of the city, military zones and barren lands in the south, some parts in the north west and north east areas and small areas in the east of Esfahan. This means that urban development isn’t the main factor of the surface temperature increase and urban heat development, but rather the type of land use has influenced the decreasing or increasing of air temperature.

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Simulation of floodplain zones in Tehran's metropolitan watershed (case study: Kaan basin)
Ezaatollah Ghanavati, Associate prof. Geographical science faculty, Kharzmi University
Ali Ahmmadabadi. Assistance prof. Geographical science faculty, Kharzmi University
Negar Gholami, MA in Geomorphology, Geographical science faculty, Kharzmi University
Extended abstract
Floodplains and adjacent rivers are always at risk from flood events due to their specific circumstances. Flood prone area identification in the watersheds is one of the basic solutions for destructive flood control and mitigation. Flood mapping is one of the best methods for flood prone area planning and identifying. Considering the importance of flood hazard, it is important to understand the role of uncertainty and incorporate that information in flood hazard maps. The hydrodynamic modeling approach is suitable for accounting various uncertainties, and thus lends itself to creating probabilistic floodplain maps. For  this purpose,  flow  boundary  conditions,  peak  instantaneous  discharge with  different  return  periods,  cross  sections and their distance and roughness coefficients for each cross section were entered to HEC-RAS hydraulic model in Kaan watershed  located  in  the Tehran  province,  Iran,  and  this model was  then  run  and  flood water surface profile at different return periods were estimated. In the Kaan Basin, most residential and agricultural lands are located in a very small distance from the river bed. The rapid growth of construction, human activities and land use change in the downstream of the basin have caused a change in the hydrological cycle and runoff production. Floodplain mapping using hydrodynamic models is difficult in data scarce regions. Additionally, using hydrodynamic models to map floodplain over large stream network can be computationally challenging. Some of these limitations of floodplain mapping using hydrodynamic modeling can be overcome by developing computationally efficient statistical methods to identify floodplains in large and ungauged watersheds using publicly.
The aim of this study is to determine flood areas within 20 kilometers of the Kaan River by using the HEC-RAS model and Arc GIS software to identify flood lands in different return periods.
The Kaan basin is located in the central Alborz Mountains. This basin is limited to south, north, east and the west respectively to Tehran, Jajrood Basin, Darakeh Basin and Karaj River Basin. The most important River in the area is the Kaan River and originated from high mountains.
Most commonly, the hydrodynamic modeling approach is used to create flood hazard maps corresponding to a rare high flood magnitude of 100-year return period or higher. Although this approach can provide very accurate floodplain maps, it is computationally demanding. As a result, the modeling approach to flood hazard mapping works well for individual streams, but its efficiency drops significantly when used to map floodplains over a large stream network. In this research, floodplain areas in the Kaan basin in return periods of 2 to 20 years are determined using the HEC-RAS model and the HEC-geoRAS extension. For this purpose, digital maps 1: 25000, DEM (10m), discharge values of Sulaghan Station, morphological characteristics of the river bed and cross sections have been used. Digital Elevation Models (DEMs) play a critical role in flood inundation mapping by providing floodplain topography as input to hydrodynamic models, and then enabling the mapping of the floodplain by using the resulting water surface elevations. Finally, the data is entered into the HEC-RAS software and analyzed. After determining the flood ranges in the various return periods at each cross-section, enter the results to the Arc GIS software and the flood zoning maps were obtained.
In this research roughness coefficients (Maning^,s coefficients) for each cross section were obtain be the
n= (nb+n1+n2+n3+n4) m                                                             (Eq.1)
Geological map and field observations have shown that the main difference between the widths of the valley in the study area is related to the type of rock. The results of the hydrodynamic model show that in the river upstream, the increase in discharge had led to the water level increase and expansion in the floodplain surfaces. But in the middle and low slopes in the downstream of the river, due to the reduced discharge, the river has a larger lateral extension and the flood areas are larger than the upstream of the river. Also, for a longer period of return, the discharge rate and the water level increase and the flood plain was more extensive. The results show that in the downstream of the basin due to instability the bed, existence of wide and eroded chanels, high ability in sedimentation, erosion of the channel bed, and low impact of vegetation, this section They can be restored and regenerated and constantly changing. Due to the location the Tehran-North high way from the Kaan basin, had the construction of roads and structures, the flood plain areas of the river should be fully observed or retrofitted.
 
Key words: Environmental hazards, Flood, Flood areas, Kaan River, HEC-RAS
 
 
 
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Zoning and Spatial Analysis of Potential Environmental Hazards
Case study: Silvana District
Abstract
Natural hazards can be considered as one of the most important threats to humankind and nature that can occur anywhere in the world. Natural hazards are one of the main obstacles to sustainable development in different countries and one of the important indicators of the development of world countries is their readiness to deal with natural hazards. Therefore, it is important to pay attention to it and appropriate measures should be taken to reduce the vulnerability of human settlements. Nowadays with increasing population growth, population dynamics and the large number of people exposed to various types of disasters, the need to identify environmental potential hazards and identification of hazardous areas are felt more and more. Meantime, some people may not be aware of potential hazards of their place of residence. So by identifying and evaluating potential hazards and their Risks before the occurrence, we can significantly reduce the severity of the damages and contribute to sustainable regional development. The negative effects of natural disasters can be minimized by the availability of comprehensive and useful information from different areas and Multihazard mapping is one of the most effective tools in this regard.
According to the above mentioned, in this study, the spatial analysis of potential hazards in Silvana district in Urmia County has been studied. This study area due to specific geographic conditions such as position, complexity of topographic and ecological structures, in general, the existence of environmental factors for hazards has been selected as the study area. There have been a number of hazards in the past and assessing of this area is necessary, because of the lack of previous studies. For this purpose, by reviewing various reports and doing field observations, three hazards including Flood, Landslide, and Earthquake are identified as potential hazards of the study area.
For assessing hazards, 12 factors in 6 clusters such as Slope, Aspect (Topographic factors), Lithology, Soil type, Distance to Faults (Geological factors) Precipitation (Climatological factors), River Network Density, Groundwater Resources (Hydrological factors), Land use, Distance to Roads (Human factors), Observed Landslide Density and Seismicity (Historical factors) as the research factors has been selected. For weighting factors, Analytic Network Process (ANP) Method in Super Decisions 2.6.0 software environment has been used. The results of the analysis show that Slope (0.201), Precipitation (0.161), Lithology (0.112), Distance to Faults (0.106), Land use (0.096), Rivers (0.078), Seismicity (0.06), Soil Type (0.055), Landslide Density (0.047), Aspect (0.033), Groundwater (0.03) and Distance to Roads (0.016), Respectively have maximum to minimum relative weight. Then, weighted maps are standardized with using FUZZY functions. For this purpose, Fuzzy membership functions such as Linear, Large and Small has been selected based on each factor. For some factors such as Slope, Aspect, Lithology, Soil type, Rivers density, Land use, Seismicity and Landslide density, Fuzzy linear function has been used. For some others such as Groundwater and Precipitation, Fuzzy large function has been used and for distance to Faults and distance to Roads, Fuzzy small function has been used. Finally, weighted maps were overlay in ArcGIS 10.4.1 environment with Fuzzy Gamma 0.9 operator and potential hazards zoning maps is obtained.
Final results indicate that major parts in the Northwest, West and South of the study area located in high risk zones and 59 percent of the total area exposed to high risk. Based on hazard zoning maps, 44 percent of the area exposed to Flooding, 48 percent exposed to Landslide and 44 percent exposed to Earthquake. Also, 61 percent of the population or 37394 people exposed to one hazard, 7 percent or 3817 people exposed to two hazard and 8 percent or 4914 people exposed to three hazard. According to surveys, only 21 percent of the study area is considered as a low risk area but that does not mean that environmental hazards will never happen in these areas. In general, and based on results, it is concluded that Silvana district has a high potential for environmental hazards. Final results of the research show that potential hazards identifying and preparation of hazard zoning maps can be very useful in reducing damages and achieving sustainable regional development. Therefore, considering the ability of hazard zoning maps to identify areas exposed to risk and assess the type of potential hazards, These analyzes should be considered as one of the most appropriate and useful tools in different stages of crisis management that can be the solution to many problems in preventing and responding to natural disasters and therefore, it is recommended that they be used in the crisis management process.
Keywords: Spatial Analysis, Environmental Hazards, Silvana, ANP Method, Risk
 

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The Spatio-Temporal Variations of Aerosol Concentration Using Remote Sensing in Sistan and Baluchestan Province (2018 - 2000)
 
 
 
Abstract
Atmospheric particles play an important role in balancing the energy budget of the Earth's surface. The Sistan and Baluchestan province because of the specific geographical conditions during the year is witnessing the spread of dust particles caused by dust storms. This paper investigates the spatial changes of this phenomenon in the region to identify the association of dust accumulation and the reasons for these concentrations. In this study, the AOD Index data of the Aqua and Terra Modis Satellite Sensor (MODAL2_M_AER_OD) with 10 × 10 km spatial resolution were used. Then, by using statistical methods, a spatial analysis was done and the temporal and spatial changes trends at 95% and 99% significance level were performed using the nonparametric Mann-Kendall method. The results showed that the maximum concentration of aerosol in areas such as Zabol, Zahak, Hirmand, Hamoun, Iranshahr, Bampour, Jazmurian basin, Chabahar, and Konarak. On average, the highest variations in aerosol concentration were in the southern regions of the province include Dashtiari, Polan, and Chabahar, and the least in the northern part of Polan, Chabahar, Konark, and Bampour areas. The trend of changes was evaluated at two significant levels of 95 and 99%. The results of this section showed that the AOD had a positive and increasing trend in June, July, and August in the areas of Dalgan, Iranshahr, Bampour, Bazman, Mirjaveh, Nokabad, Zahedan, Nosratabad, Zaboli, Qasrqand, Irandegan, and Sib-va-Soran Plain and areas such as Korin, Zabol, Zahak, Sirkan (Bamposht), Hamoun have a negative and decreasing trend. The average changes in aerosol concentration in June, July, and August show a significant increase in the aerosol concentration from 2015 to 2018 up to 0.8.
 
Keywords: Environmental Changes, Dust, Environmental Hazards, Climate.

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One of the causes of environmental hazards is the change in the pattern of surface water flow in floodplains following the construction of flood Spreading networks. The purpose of this study is to prepare a zoning map of vulnerable areas of the flood Spreading station of Musian plain  in Ilam province after the implementation of the aquifer project in this plain. To prepare this map, five factors influencing the change in flow pattern including elevation, slope, flow direction, geological formations, and landuse change were examined. Then, in the GIS environment, each class of the mentioned factors was given a score of zero to 10 based on the range and the corresponding weight layers were created. Then, by combining the created weight layers, the vulnerability zoning map of the area was created based on 5 classes: very low, low, medium, high and very high. The results showed that the most important threat and danger factor is the concentration of waterways behind erosion-sensitive embankments. Also, the study area in terms of vulnerability includes three classes with medium risk, high and very high and covers 16, 62 and 22% of the area, respectively. Flood and upland Spreading areas, risk areas and lowland lands are the most vulnerable parts of the basin in terms of floods and sedimentary deposits.

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Risk modeling of plant species diversity and extinction in Sorkheh_hesar National Park
 
Zahra Mosaffaei¹, Ali Jahani^2*, ³MohammadAli ZareChahouki, ⁴Hamid GoshtasbMeygoni, ⁵Vahid Etemad
 
¹ Masters of Natural Resources Engineering, Environmental Sciences, College of Environment, Karaj
^*2Associate Professor, Department of Natural Environment and Biodiversity, College of Environment, Karaj.
³ Professor, Department of Restoration of arid and mountainous regions, University of Tehran, Karaj
⁴ Associate Professor, Department of Natural Environment and Biodiversity, College of Environment, Karaj
⁵ Associate Professor, Department of Forestry and Forest Economics, University of Tehran, Karaj
 
 
Abstract
Full identification of hazards and prioritizing them for non-harm to nature is one of the first steps in natural resource management. Therefore, introducing a comprehensive system of evaluation, understanding, and evaluation is essential for controlling hazards. This study aimed to model and predict environmental hazards following increased degradation in natural environments by ANN. Thus, 600 soil and vegetation samples were collected from inhomogeneous ecological units. Soil samples were prepared by strip transect method according to soil depth in four profiles (5, 10, 15, 20 cm). Vegetation samples were also collected using a minimum level method using 2 2 square plots according to the type, density, and distribution of vegetation. Sampling was done in two safe zones and other uses were modeled using ANN in MATLAB environment. The optimal model of multilayer perceptron with two hidden layers, sigmoid tangent function and 19 neurons per layer and coefficient of determination of 0.90. The results of sensitivity analysis showed that soil moisture content would be effective in decreasing biodiversity and flood risk as well as increasing the risk of extinction of endemic species in the region, and then the apparent and true gravity and soil porosity and distance from the road play a key role in the degradation of cover. Vegetation has increased flooding and extinction risk. Therefore, it is recommended that measures related to soil and vegetation restoration in this park be taken to reduce future damages as soon as possible.
 
Keywords: Modeling, Artificial Neural Network, Environmental Hazards, National Park, Vegetation