مجله مدیریت مخاطرات محیطی
سال هفتم شماره 2 (تابستان 1399)

One of the most contagious and infectious diseases of the 21st century is the coronavirus (Covid-19), which has been spreading worldwide since the end of December 2019 as a pneumonia outbreak from China. Analysis of spatial-temporal patterns of Coronavirus using GIS is important in understanding the geographical distribution of this epidemic as well as epidemiological and community health studies in the country. Therefore, it is necessary to study the geography of this disease in order to control and prevent it; Therefore, in the present applied and descriptive-analytical research, using spatial statistics, it has performed spatial-temporal analysis as well as spatial modeling of coronavirus epidemiology in the country. The statistical population of the present study is 31 provinces of the country. The data of Corona virus patients were analyzed in the period from March 24, 2017 to April 24, 2012 (21638 people) using ArcGIS software. The results of spatial correlation show that the provinces of Tehran, Alborz, Qom, Mazandaran, Gilan, Qazvin, Isfahan, Semnan, Markazi and Yazd are in the HH cluster, which means that the number of people infected with coronavirus in these provinces is higher than average. 32.26% of the country's provinces. Also, the analysis of hot spots on the number of people infected with Coronavirus showed that the provinces (Qom, Tehran, Golestan, Semnan, Isfahan, Mazandaran and Alborz) in the hot clusters and the provinces (Bushehr, Ilam and Kermanshah) in the cold clusters. Are located. The results of the study indicate that the most important geographical factor in the spread of coronavirus in the country is the distance and proximity of the provinces affected by the disease, which follows the pattern of compatible spatial distribution.

The main objective of this study is to identify and prioritize the risks of construction projects with a focus on dam-building projects, according to PMBOK standard. Method of Failure Mode and Effect Analysis (FMEA) and its risks, using multi-criteria decision-making techniques namely Additive Ratio Assessment (ARAS) and Analytical Hierarchy Process (AHP) in a fuzzy environment are applied to try to provide practical solutions. 31 experts’ opinions are collected in tow steps which in the first one their opinions about the potential risks of construction projects with a focus on dam-building projects are considered; while the second step expressed in qualitative terms for parameters probability of risks’ occurrence, severity of risks’ impacts, and capability of risks’ prediction before occurrence. Results show that the Risk Priority Numbers (RPNs) were calculated in a range of 80.7 for lack of experienced project engineers to 274.5 for the delay in paying contractors. Also “delay in providing equipment” with the rate of 1.000 was ranked as 1, “financial issues” with the rate of 0.980 was ranked as 2, and “delay in notifying the plans with the rate of0.909 was ranked as 3 were indicated as the most important potential risks in dam-building projects.

In the previous 50 years, rapid growth of tourism industry has been imposed a lot of destructive results on ecology. Reaching to a sustained tourism in a vast area as an important principle, is impossible unless by recognizing biological, environmental factors on tourism and considering of vulnerable spots in implementing of tourism projects in countries such as Iran in which ecological assessment is ignored or is the last priority. In Langaroud city, the industry of tourism left various changes on tourism centers. Therefore, the main purpose of this research is considering and evaluating effective factors on ecological vulnerability of tourism centers in Langaroud city. The method of research is navigation, and the proper tool for collection of data is inquiries that have distributed among tourists and local community. The statistical community includes 383 participants that acquired results from these inquiries on the basis of kochran formula have been calculated. In order to analysis of data from SPSS and ESPRS correlation coefficient tools have been used. The results have indicated that man–made artificial phenomena has a negative effect on ecology of local, poor managerial decisions in evaluation, implementation of tourism projects, overlooking the violators, lack of cooperation between tourists and local community and uncontrolled growth tourism. Although has positive effects beside it. At the end, according to the weights obtained from statistical analysis and evaluation of centers, appropriate strategies have been proposed.

 One of the most important challenges that agriculture has encountered with, is the overusing of nitrogen fertilizers. Excessive use of these fertilizers, not only proliferate the costs of production and harm human health but also expand environmental pollution. Improving the efficiency of the nitrogen fertilizers depends on monitoring the plant nitrogen status at the different stages of plant growth and applying a sufficient amount of fertilizer at the right time and right place. Considering the necessity for diminishing the harm of nitrogen fertilizer overuse on human health, research was conducted to identify nitrogen stress in the maize field as a new approach for optimization of the use of those fertilizers by means of a new, fast and non-destructive aerial multispectral remote sensing technology via UAVs. The experiment was carried out on a maize field in a randomized complete block design in 4 replications of urea fertilizer in 4 treatments including 0% (witness), 50% (critical range), 100% (adequate range), and 150% (maximum or toxic range). Urea fertilizer was utilized with irrigation water in two growth stages, including the 8-leaf stage (V8) and tasseling appearance stage (VT). Multispectral aerial imaging was accomplished in both maize growth stages. In order to ground Sampling, 10 specimens of maize plants were randomly selected from each treatment in those plant growth stages. At first, the amount of chlorophyll was measured for each sample, next, the amount of nitrogen was delineated by the Kjeldahl method. After taking the images, they were processed. The vegetation indices including NDVI, NRI, MTVI2, CI, GM, which were related to plant chlorophyll amount and nitrogen content, were calculated. Data analysis for nitrogen concentration stress indicators, with leaf chlorophyll content, considering their variable relationships, was performed by the fitting regression models. Based on our research, CI (R^2=0.88) and NRI (R^2=0.90) index were the most appropriate indicators for detecting nitrogen stress in the V8 and VT growth stage of maize, respectively. According to our results, aerial multi-spectral remote sensing is capable of detecting the variability and stress of nitrogen fertilizers in the maize field.

Floods are one of the three main natural hazards in Iran, and it is safe to say that significant floods occur at least once a year in this part of the country. According to studies, 40 small and large floods occur annually in all parts of the country. This highlights the need to study the factors influencing the occurrence of floods. The purpose of this study is to zoning flood prone areas in the region and determine the priority of factors affecting flood occurrence using a random forest algorithm. Thus, according to the studies and research background, 9 land use indicators, distance from the river, slope, height, humidity index, river flow, waterway capacity, precipitation, and land curvature were selected. After determining the variance inflation factor and tolerance coefficient, in the next step by entering the data related to the effective factors to the R software, modeling was performed using a random forest algorithm and the role of effective factors in flood occurrence in each sub-basin was determined. Flood risk zoning was prepared in four very dangerous, dangerous, medium and low risk zones in ARC / MAP 10.2 environment. The results show. . According to the research results in all sub-basins, rainfall is the most important factor in the occurrence of floods in the region. In the northern and western basins of the Dubai River region and the slope of the next ranks have played a role in the occurrence of floods, while land use in the southern sub-basins of the region is an important factor in the occurrence of floods. Also, according to the results, more than half of the area is located in a very dangerous and dangerous area. Most of the dangerous and very dangerous zones cover the northern, northwestern and western parts of the region, which include the sub-basins of Fasham, Meghun and Ahar.

The spread of the corona virus is one of the most important challenges in the world today, and the epidemic of this virus has affected all sections of society, including universities. As with any challenge, the coronavirus epidemic has posed many threats and opportunities for universities and the academic community. This crisis has led the scientific community to gain valuable experience in electeronic learning and be ready to enter a new era of teaching in new ways, including learning in three-dimensional spaces. Culture and art are also linked to education, and this can be the beginning of a move towards global integration in the education process. In recent months, many conferences have also been held virtually, which have been widely welcomed. Global policies have also taken measures to increase the budget for applied sciences so that, the National Science Foundation's budget is shifting from $ 8 billion a year to $ 40 billion. On the other hand, the Covid-19 epidemic has attracted the attention of researchers in various fields and it has changed the direction of world-wide research towards the basic sciences and finding solutions to treat this virus. This will pose a budget problem for some other research areas. Many universities around the world have also faced a number of problems due to the cyberspace approach, including declining enrollment of international students and lack of funding, and this has threatened the lives of some universities. Now, more than eight months after the onset of the coronavirus epidemic, universities around the world have made valuable arrangements to maintain and enhance their educational goals and to adapt more and more to this global crisis. Given the above, in this article we look at these valuable approaches globally. It is hoped that by taking advantage of scientific participation and transferring useful experiences at the global level, we can turn this threat into an opportunity to improve and enhance the level of science and awareness in the country.