نشریه تحلیل فضایی مخاطرات محیطی
سال نهم شماره 1 (بهار 1401)

In this study, the relationship between dieback of Persian oak trees and drought in Ilam province has been investigated. The main purpose of the research is to introduce a suitable model of relationship between oak dieback and drought. So from SPI and NDVI indicators and Moran index and statistical regression statistics and satellite images of Modis and Landsat have used to analyze the relationship between dieback of Ilam forests and happened drought in the region. The precipitation data of 93 rain gauge stations were analyzed during the statistical period and according to the dry coefficients of SPI index, drought zoning layers of Ilam province were prepared for two time series of 2000 to 2009 and 2010 to 2019. Greenery's raster layers were prepared from Modis satellite imagery for the mentioned time series. The results of analysis of Moran's statistical showed a significant correlation between the SPI index and the NDVI index in spatial dimensions. By a simple random method, 143 points of oak dieback with dimension of 30 m2, which each point was equivalent to a pixel-size, were recorded with a GPS device, and by simulating in satellite imagery, the droplet layer of oak dieback was extracted. Although linear regression between extracted oak dieback points with SPI and Moran statistical indicators was significant, but the relationship between NDVI index and Moran statistic has the effect of independent variable of drought trend in spatial and temporal dimensions on the dependent variable process of oak drought with spatial analysis. And nonlinear regression has a more appropriate and accurate statistical significance and explanation. So this method as desirable method has been introduced for analyzing of drought and oak dieback.

With the observation of the first confirmed case of Covid-19 in Qom on 20 February 2020, restrictions were imposed by the government and executive agencies to prevent the spread of the Covid-19 virus in all cities of Iran. These restrictions seem to reduce the production and release of air pollutants from human resources. Therefore, this study was conducted to investigate the changes in the time series of sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone pollutants before and after the outbreak of the Covid-19 virus in three metropolises of Tehran, Isfahan, and Mashhad using Sentinel-5 satellite data. For this purpose, using the Google Earth Engine system, the concentrations of these pollutants are averaged monthly in the two periods of 20 February  2019 to 20 February 2020 for the period before the outbreak of Covid-19 and the period of 20 February 2020 to 20 February  2021 for the period of outbreak of Covid-19 Was considered. Then, to evaluate the significance of the change in the concentration of these contaminants before and after the outbreak of the Covid-19 virus, a t-test (dependent t) was used at a significance level of p-value <0.05. The results of the T-test showed that for sulfur dioxide, nitrogen dioxide, and carbon monoxide pollutants in all three cities there was no significant change in the mean data concentration; But ozone for all three cities had a decreasing trend and a significance level of p-value <0.05. The results of this study showed that the application of restrictions has not been effective in reducing the release of primary pollutants from human resources.

To support the proper management of ecosystems, vulnerability analysis of ecosystems is very important. Vulnerability analysis of ecosystems provides information about weaknesses and capacity of the studied ecosystem for recovery after damage. Considering the degradation status of Miangaran wetland, vulnerability evaluation of this wetland is one of the most important management methods in the region. For this purpose, in this study, after identifying and evaluating the threatening factors of Miangaran wetland, these factors were scored using evaluation matrices. Then, the interaction between these values ​​and threatening factors was examined and the vulnerability of wetland values ​​was obtained by multiplying the scores of all studied factors. Finally, management solutions were presented to deal with the most important threatening factors. According to the results, the most vulnerability is to the hydrological and ecological values ​​of the wetland. The highest effects of threats on the ecological value are also on the birds of Miangaran wetland. The results of the evaluation of Miangaran Wetland show that this wetland has a high potential for ecosystem functions of the wetland. These functions have been neglected in the planning and managing of wetlands at the local, regional and national levels. As a result, ecosystem-based management is suggested as the best management approach. The management in these areas should take action to prevent the vulnerability of Miangaran wetland. Also, the vulnerability evaluation method used in this study can provide a good understanding of the relationship between wetland functions and the resulting services for the management of the ecosystem of Miangaran Wetland.

landfills in the country and abroad and by examining the conditions of the region. The study and the influencing factors are compiled in the study area. The layers related to each criterion in the relevant table will be prepared, processed and converted from the relevant organizations. The method of this dissertation is applied-modeling in terms of purpose, because on the one hand, the concepts and rules related to the field of knowledge are carefully analyzed, and on the other hand, the relationships between these concepts and rules are evaluated and determined by experts. In this study, there is a need to use the decision theory method to evaluate and investigate the status of construction waste disposal along roads to increase trust and confidence in decision making. The most important results of the study of the dumping of construction debris along the roadsides are that, 1- The most important criterion in the cluster "Environmental factors of construction waste disposal" with code (A), "Soil pollution in the city" with code (AB) with fuzzy network weight of 0.096; And 2- The most important criteria in the cluster "Applications of GIS in urban management of construction debris disposal" with code (B), "Urban green space management" with code (BA) with fuzzy network weight equal to 0.191; And "Urban management related to health" with code (BB) with fuzzy network weight equal to 0.120; Were calculated. on the other hand, 3- The most important criterion in the cluster "Economic factors of construction waste disposal" with code (C), "Construction waste management training cost" with code (CD) with fuzzy network weight equal to 0.123; Prioritized, The results of the present study can be said that, after reviewing the theoretical foundations of the research and reviewing the research background, it was found that due to research gaps in the fields of economic factors of construction waste disposal, GIS applications in urban management, construction waste disposal, environmental factors, Utilization of a combined fuzzy multi-criteria decision-making methodology to investigate the status of construction debris dumping along roadsides; It is possible to realize the innovation of the present research in filling the mentioned research gaps.

Soil erosion is one of the environmental problems that is a threat to natural resources, agriculture and the environment, and in this regard, assessing the temporal and spatial amount of soil erosion has an effective role in management, erosion control and watershed management. The main aim of this study was to estimate soil erosion in Amoqin watershed and its relationship with well-known vegetation-based and topographic-related indices. The meteorological data has been used to determine the rainfall erosivity. The rainfall erosivity index was calculated using the modified Fournier index during the 10-year available recorded rainfall data. The value of LS factor has been calculate using digital elevation model. Meanwhile, C and P factors were determined based on the utilization scheme and condition of the study area. Data were analyzed and processed using ArcMap 10.1, ENVI 5.3, and Excel software. In this study, RUSLE model was used to estimate soil erosion, in GIS environment. According to the results, the amount of factor R in Amoqin watershed varies from 12.32 to 50.52 MJ/ha/h per year. The variation of soil erodibility index (K) over the study area is between 0.25 to 0.42. The amount of LS factor varies between 0.19 and 0.38, which is more in high slopes, especially around the waterways and uplands of the study area. The variation of C factor was estimated to be around -0.18 to 0.4. In general, it can be said that the central part of Amoqin watershed has less C value due to the greater area of agricultural activities and the highest amount is related to western areas, especially southwest areas because existing the rangeland areas. Due to the lack of protective measures in the study area, the amount of factor P was considered as unity for the whole region. The base layers of RUSLE factors were obtained and overlayed in GIS to calculate the soil loss in tons per hectare per year. The map of annual soil loss indicate that the erosion amounts varies between 1.21 to 5.53 tons per hectare per year in different parts of the study area. According to the results, the vegetation factor with a coefficient of determination 0.47% had a significant correlation with soil loss. The stream power index with the coefficient of determination of % 0.07% had the lowest correlation with soil erosion values.

Global warming and the heat islands of cities are one of the biggest challenges in the world today. Cold islands is a word that stands in front of heat islands and refers to areas of the city that have lower temperatures than the surrounding areas. In this study, in order to investigate the factors affecting the formation of cool and heat islands of the city, it was first obtained by using Landsat image processing and using the single-channel surface temperature algorithm. Then to investigate the parameters affecting the land surface temperature changes; Criteria for changes in particulate matter and changes in vegetation were considered. The NDVI index was used for vegetation and the algorithm proposed by Saraswat et al. was used for the amount of particulate matter. According to the results, the highest ranking neighborhood  for heat islands were in Bustan, Shahid Bagheri township and the airport, respectively, and the lowest amount of cool islands were in Baharan, Niavaran and Darband, respectively. Pearson coefficient obtained from the relationship between surface temperature and vegetation was -21.29%, which indicates the inverse relationship between temperature and vegetation, as well as the amount of vegetation index in hot and cold regions. Regarding the relationship between land surface temperature and air pollution, the correlation between these two parameters was equal to 19.31% and comparing the pollution index in areas with cold and warm islands showed that there is a significant relationship between reducing air pollutants and cold islands but the opposite is not true.

The purpose of this study was to investigate the relationship between drug abuse and socioeconomic factors in Dizaj Abad village of Zanjan township. Type of research is applied and its nature and method is Descriptive-Analysis. Data collection method is library and fieldwork (Observations, interviews and questionnaires). The questionnaire is basically composed of closed questions and answers in the Likert scale (five scale). The formal validity of the questionnaire was confirmed by a panel of experts. Cronbach's alpha has been used to measure the reliability of the indices, which is 0.784%, indicating their suitable value. Data were analyzed using Correlation tests, Mann-Whitney and t-test. In Arc GIS software, hot spot analysis tests and Anselin Local Moran's index and Geographic weighted regression was used for cluster analysis and weighting. The results of the tests show that people with low education have higher addiction than other people and income level has no significant relationship with addiction and drug abuse. according to Z statistic, Level of education items (-4.688) and with significance level of 0.000 had the most significant relationship with drug addiction and abuse and job items with -0.730 and significance level of -0.465, income level of -0.594 and level of significance 0.553 had no significant relationship with addiction and drug abuse.

Introduction Dust storms are one of the significant phenomena in the desert areas of the world. It is internationally agreed that days with visibility below 1000 metres due to dust present in the air are a result of strong winds. This atmospheric phenomenon causes damage or environmental, social and economic damage. Dust storms with visibility of fewer than 200 meters are the most severe storms that can occur in an area. Such storms disrupt the normal life of the residents and cause damage. In this research, the temporal and spatial distribution, as well as the occurrence of such storms in the two regions of southwest and west of Iran, have been investigated. Preliminary evidence indicates an increase in the frequency of these storms. On the other hand, these two regions are important regions of Iran in terms of agricultural and industrial production and population centers. The increase of such storms can cause serious damage to the economy, agriculture and health of the two population poles of the country. For analytical comparison of dust storms in Iran, two regions, 1- southwest including (Khuzestan, Kohkiluyeh and Boyer Ahmad and Chaharmahal and Bakhtiari provinces); 2- west including (Ilam, Kermanshah, Kurdistan, Hamedan and Lorestan provinces) it's been chosen. To select sample stations, after receiving dust data from all synoptic stations of 8 provinces from the Meteorological Organization, including (88 synoptic stations), the data were analyzed. According to the aim of the study, which was to investigate the trend of changes in the phenomenon of severe dust in the last three solar cycles (33-year statistical base), 28 stations of the above stations had the desired conditions. Then, the data with horizontal visibility less than 200 m were sorted. Frequency of dusty days in Excel environment; Extracted daily, monthly, seasonally and annually. SPSS software was used to investigate the traits and data scatter. Finally, from ArcGis10.6 software to draw maps, as follows; The topography of the area is shown as a zoning map and quantitative characteristics of dust events are displayed as a Bar / Column.

To support the proper management of ecosystems, vulnerability analysis of ecosystems is very important. Vulnerability analysis of ecosystems provides information about weaknesses and capacity of the studied ecosystem for recovery after damage. Considering the degradation status of Miangaran wetland, vulnerability evaluation of this wetland is one of the most important management methods in the region. For this purpose, in this study, after identifying and evaluating the threatening factors of Miangaran wetland, these factors were scored using evaluation matrices. Then, the interaction between these values ​​and threatening factors was examined and the vulnerability of wetland values ​​was obtained by multiplying the scores of all studied factors. Finally, management solutions were presented to deal with the most important threatening factors. According to the results, the most vulnerability is to the hydrological and ecological values ​​of the wetland. The highest effects of threats on the ecological value are also on the birds of Miangaran wetland. The results of the evaluation of Miangaran Wetland show that this wetland has a high potential for ecosystem functions of the wetland. These functions have been neglected in the planning and managing of wetlands at the local, regional and national levels. As a result, ecosystem-based management is suggested as the best management approach. The management in these areas should take action to prevent the vulnerability of Miangaran wetland. Also, the vulnerability evaluation method used in this study can provide a good understanding of the relationship between wetland functions and the resulting services for the management of the ecosystem of Miangaran Wetland.

Extream snowfall event that may occur at any time during the cold season, has significant social and economic implications. Therefore, the economic and social consequences of these events reveal the importance of identifying the synoptical mechanisms associated with the extream snowfall events. In order to achieve this goal, using daily precipitation and temperature data during the statistical period of 1951-1 2016 and based on multiple criteria, the two three-days extream snowfall events were identified during February 7-9, 1972 and February 2-4, 1988. After selecting samples, a statistical analysis of the teleconnection indices was done and then, using the NCEP-NCAR reanalysis data, the combined patterns of surface and lower, middle and lower troposphere were plotted in the form of three-days mean. Results obtained from analysis of teleconnection indices and their correspondence to the synoptic patterns indicate the weakening of the tropospheric polar vortex and its division into multi-centers in the periods of extream snowfall events. In the event of February 7-9, 1972, though the centers were moved to mid-latitudes, but they are not completely out of the Arctic and to some extent maintain their position in this area. In February 2-4, 1988, the vortex centers have shown a more equatorwards displacement towards the mid-latitudes that the emergence of negative phases of the NAM and AO represent such a situation. However, in both events, the strong and main center of the polar vortex is located in the eastern hemisphere and therefore in a state close to Iran. The weakening of the sub-tropical jetstream in the eastern hemisphere, especially in the Mediterranean, has resulted in the transmission of potential vorticity tabs to mid-latitudes. The equatorwards progress of these tabs has led to the formation of the trough in the western and eastern Mediterranean regions that accompany with a ridge between them, led to the formation of omega bundle patterns and split flow, respectively, in the events of February 1972 and 1988 in this geographical area. The southern boundary of the progress of the troughs has specified by index contour of the edge of the vortex by 552 gpdam, that extends to the southern part of Iran and in the February 1972, event compared with the pattern of the February 1988, had the more-equatorwards progress toward the middle latitudes, and as a result, over Iran.

In this study, combinated synoptic analysis method was used to identify the role of atmospheric circulation patterns in the occurrence of severe air pollution in Esfahan. To perform the research, data from air pollution stations, digital atmospheric profile data, and HYSPLIT outputs over a 11-year period (2004-2005) were used. The results show that the highly pollutated days of the city of Esfahan can be explained by the four synoptic patterns. The occurrence of days with extremely severe pollution in Esfahan, rather than being rooted in local factors, is due to the interaction of local conditions with atmospheric circulation at the regional scale. In other words, the city of Esfahan will only experience extremely polluted days when the atmospheric circulation of the atmosphere provides conditions for increased concentrations of pollutants. The main causes of the occurrence of days associated with maximum contamination can be attributed to Subtropical high latitude and its progression to higher latitudes. This circulation system contributes to the occurrence of highly polluted days on most days, either directly or in combination with other atmospheric systems.

One of the dangers that has caused cities to face a serious crisis is the outbreak of Covid-19 disease. The corona pandemic has taken cities out of their normal routine. Therefore, cities seek to return to their past conditions and urban resilience as soon as possible. Research Method In this descriptive-analytical study, using field survey, four economic, social, managerial-institutional and infrastructural dimensions in the form of 29 items have examined the resilience of Tehran against Corona pandemic. In research, support and advocacy for affected businesses, insurance coverage, support for affected manufacturing sectors, are in the most unfavorable situation. The results obtained from the final table of Vikor technique show that the economic index with a score of 1 is the most important component of resilience against coronavirus, which is lower than other components of resilience. After that, the managerial-institutional component with a score of 0.94 and the infrastructure component with a score of 0.92 in the next ranks are the most important components of Tehran's resilience against coronavirus. The results show that the metropolis of Tehran is not in a favorable position in relation to the corona virus and is not resilient to selected indicators and the economic index has the most impact and the social index has the least impact on the resilience of Tehran.