مجله مدیریت مخاطرات محیطی
سال هشتم شماره 2 (تابستان 1400)

Landslide is one of the natural hazards which occur worldwide and causes loss of life and property every year. Landslide risk control and management have a vital role in reducing its damage. The first step of landslide risk management is to identify areas prone to landslides, for which different methods have been proposed. Evaluating these methods can provide valuable information to managers and decision-makers. In the present study, the landslide susceptibility map of Mazandaran province was produced using statistical index and confidence factor methods. Besides, to increase the accuracy of the maps, new methods by combining the index of entropy method with each one of statistical index and confidence factor methods have been proposed. To evaluate and compare the methods, 585 landslide data that occurred in a period of 50 years in Mazandaran province have been used. Fifteen conditioning factors have been considered to have the most effects of landslide occurrence, which were divided into four categories: topographic, hydrological, environmental and man-made, and geological. The results showed that topographic factors, among the others, have the most impact on landslide occurrence. In addition, comparing the accuracy of susceptibility maps generated using hybrid methods with SI and CF methods showed an increase of 3% and 3.5% (based on urea under curve index).

Occurrence of wildfires in forests is one of the important environmental hazards. Remote sensing is one of the useful sources for detecting and monitoring wildfires. The purpose of this paper is to evaluate "during fire" image and "before and after fire" images from Landsat8 satellite in identifying fire areas using Support Vector Machine (SVM) and Random Forest (RF) classifiers. Based on the analysis of the output from the images of the Sacramento area in the state of California, it was found that RF classification method with an overall accuracy of 99.83%, compared to the SVM method with an overall accuracy of 99.53%, has a better ability to distinguish fire from non-fire areas. It should be noted that in both methods, the overall accuracy was considerable and indicated their desirability to wildfire detection. Moreover, the classification results with a “single image” input during a fire were better than the “difference image” input.

Human and natural factors cause the river to be out of equilibrium and this imbalance leads to changes in erosion and sedimentation. One of the forms of erosion in rivers is stream bank erosion which can change the plan and morphometry of the river and due to these changes, various hazards including : Change the morphometry of the channel and produce sediment may happen. Changing in river's pattern, longitudinal and transvers displacement of the river, occurrence of bank accretion, changing hydrological and geometric characteristics can be the results of change in river's sedimentation and erosion. Monitoring the variables affecting the stability of bank and stream characteristics can be effective in preserving human life and property also managing the natural environment. In this research the method of Rapid Geomorphic Assessment (RGA) has been used for investigate the stability and morphometric change in Haji Arab river that located in south of Qazvin province. For this purpose were chosen 8 reaches. Field studies and mapping were done from all reaches. The parameters of Oklahoma Ozark Streambank Erosion Potential Index (OSEPI) were scored during the field studies. In this research have been used statistical analyzes. Results show that the unstable stream banks belong to reaches of 1 in left side (down strem) and 7(up stream) in right side also the stable reaches are the reaches of 2(down stream) in left side and reach of 3 in right side. the most effective factor in stability of Haji Arab river's bank in both sides is riparian woody vegetation after that in left side stream curvature and in the right side Stream Curvature, Percentage of Bank Height with a Bank Angle Greater than 80 o, Unconsolidated Material equally are the most effective factor in stability.

One of the serious challenges of rural settlements in developing countries is the issue of socio-economic sustainability, which despite the systematic relationship with environmental sustainability is largely overshadowed and less independently conceptualized and studied. These two dimensions, in connection with which a significant part of the instability of the country's rural settlements are concerned, emphasize more than anything else the concept of intergenerational justice. The purpose of this study is the spatial distribution of socio-economic sustainability indicators in rural areas of Ilam province and also study this issue of what environmental factors and forces have caused spatial differences in these areas using spatial analysis in GIS for sampling, among 378 villages with more than 20 households, 37 villages were selected as a sample and 250 questionnaires were completed by the villagers. The research method in this article is descriptive-analytical and for data collection were used of two methods field ‌ libraries. Also, data analysis was performed by one-way analysis of variance and Tukey test in SPSS software and GIS. The results of the analysis of variance test show that is accepted the difference between the average social and economic dimensions in the levels of rural settlements, also, the results of Tukey test show that the spatial distribution of socio-economic sustainability indicators in the study area is different, which is affected by environmental factors and forces in the region.

Improving the safety of the country's schools as a gathering place for students is an undeniable necessity. To benefit from a safe school, in addition to the standard structure and stabilization of non-structural components, the readiness of those involved in dealing with the earthquake and sufficient knowledge about the tasks and duties to be performed before, during and after the earthquake are also very important. School principals, as the pioneers of decision-making and planning in the school executive space, are the basis for the realization of these factors in schools. Therefore, the present study was conducted to analyze the perceptions and lived experiences of school principals, to identify the themes and sub-themes related to school preparedness against earthquakes. For this purpose, a qualitative approach and a descriptive phenomenological method were used. Data were collected through in-depth and semi-structured interviews. Using standard sampling, data saturation was obtained after 14 interviews. Interviews were analyzed using MAXQDA2018 software based on Colaizzi’s strategy. The analysis of the interviews identified five main themes, including "prerequisites", "seismic safety measures", "training and maneuvering", "active participation of actors" and "thematic knowledge and approach of school principals". Findings show that the promotion of seismic safety in schools should be done more quickly and it is necessary to allocate a certain budget for the education and maneuver of the schools and provide adequate and safe escape routes in schools. Accelerating the process of comprehensive safety of schools against earthquake requires the active approach of their principals and their constructive and effective interaction with experts, teachers and parents.

Today, smuggling of goods and currency has caused extensive cultural damage to the country and deprived the nation of legitimate incomes, in addition to the harmful effects of smuggling on domestic production and economic anomalies caused by this phenomenon of social and cultural anomalies through changing culture and taste. Household consumption leads to smuggling of non-standard goods by weakening domestic production. The present study examines the prevention of smuggling of goods and currency through the use of strategies of resistance economy and strengthening national production. The research method is applied in terms of purpose and in terms of field information collection method and in terms of methodology is descriptive-survey type. The statistical population in the qualitative stage was the experts of organizations and institutions involved in the issue of smuggling of goods and currency (work experience of at least 10 years) and experts of companies involved in the export and import of goods (work experience of at least 10 years) who were selected theoretically. In a small stage, the employees of organizations and institutions involved in the issue of smuggling of goods and currency, as well as the employees of companies involved in the export and import of goods. Sampling methods were qualitatively available in the qualitative stage and simple in the quantitative stage at random. The data collection tool was a researcher-made questionnaire based on strengths, weaknesses, opportunities and threats. The data were analyzed based on SWOT method and finally it was concluded that in order to boost national production and a resilient economy to prevent the smuggling of goods and currency, a series of defensive, competitive, aggressive and strengthening strategies of religious culture have been proposed.