مجله مدیریت مخاطرات محیطی
سال دهم شماره 1 (بهار 1402)

The present study investigates and analyzes the role of hydrogeomorphic parameters in flood susceptibility of sub-basins of the Siah Cheshmeh basin located in West Azerbaijan province. For this purpose, first, the study area was divided into 6 sub-basins based on topographic and drainage characteristics using a digital elevation model (DEM) with a spatial resolution of 12.5 m. In the next step, 8 hydrogeomorphic parameters including Stream order, Streams length, Drainage density, Compactness coefficient, Circularity ratio, Form factor, Basin relief and Ruggedness number were prepared using Horton, Schumm, and Strahler geomorphological rules in ArcGIS software. Then, to weight the parameters, the SWARA multi criteria decision-making method was used, and the relative weight of each of the eight parameters was determined for the 6 studied sub-basins. The results of weighting and prioritization showed that sub-basins 2 and 4 with the weight of 0.276 and 0.250, respectively, have the highest weight and have very high flood susceptibility. In contrast, sub-basins 3, and 5 with weights of 0.105, and 0.061, respectively, had the lowest weights in terms of 8 parameters, and therefore, in terms of Flood susceptibility is very low in the class. The total area of the sub-basins that are in high and very high classes (sub-basins 2, and 4) is about 327 Km2, which includes 33.8% of the total area of the basin.

PM2.5 pollution is one of the critical environmental problems that occurs after industrialization and the increase in the population of cities. Information about pollutant concentration, including PM2.5 pollutants, significantly impacts how city managers make decisions to improve cities' health. This study used the ordered weighted averaging (OWA) technique to produce PM2.5 pollutant zonation. For this purpose, meteorological information layers include wind speed, maximum temperature, minimum temperature, average temperature, 24-hour precipitation and humidity, normalized vegetation difference index layers (NDVI), and road density are used. The gradient descent algorithm has been used to calculate the weights related to the order of the values to apply the OWA algorithm. The optimal learning rate parameter has been obtained to achieve the optimal value of the weights. Also, the layers of information were combined based on the obtained weights from OWA. Finally, the RMSE index was used to evaluate the obtained results, and the PM2.5 pollutant estimated for the summer and winter seasons had the lowest and highest errors, respectively. The error values for these two seasons were 0.129 and 0.190, respectively. Also, Aqdasiyeh station had the lowest error in all seasons, and Golberg, Region 11, and Shahr-e-ray stations had the highest error.

Along with the growth of technology, and the increase of natural hazards in the contemporary world, human life is faced with many challenges, deal with social responsibility has major importance to prevent hazards and reducing their unfortunate consequences for humans which leads to a healthy relationship between people and the environment. To explain the factors affecting social responsibility, the current research examines the existing theories and analyzes previous research findings. The research method of this study is the documentary which explores studies related to the subject that was published from 2011 to 2022. The cited sources were obtained by searching the keywords: social responsibility, social indifference, social commitment, risk of Covid-19, and risky society. The data has been analyzed by attributive and holistic coding and factors related to social responsibility in a risky society, and have been categorized using the obtained results. Findings show that crises and risks can change people's actions and social responsibility is an important factor that affected the actions and relations between actors in crisis conditions. The final results based on holistic coding have extracts, 7 main categories, and 18 sub-categories. The important factors affecting social responsibility are social capital, moral and normative values, and inequality in various dimensions such as power, health, identity, awareness, and indifference, which have the greatest impact in a risky society. These factors through the concepts such as insecurity, citizenship, and altruism affect social responsibility.

Natural hazards are recurring phenomena that can cause significant material and moral damage. Reducing vulnerability to these hazards depends on citizens' understanding and recognition of them. In Iran's current education system, textbooks are the primary teaching tool for this issue. Therefore, it is necessary to evaluate how natural hazards are represented in these textbooks. This study uses content analysis to examine the images and contents of guidance, geography, and human and environment textbooks. The results show that only a small percentage of the textbooks' content was dedicated to natural hazards. Specifically, (6.4%) of social studies course content in middle school textbooks and (7.1%) of first and second grade high school geography textbooks were related to natural hazards. In the third year high school geography book, (33%) of the content was related to hazards, with earthquakes (26%), floods (40%), droughts (14%), and landslides (13%) being the most frequently discussed hazards. In "Human and Environment" textbooks, only (21.2%) of the topics were related to natural hazards, which is insignificant compared to the total contents.

The studied area is located as a part of the Caspian Sea catchment with an area of ​​about 50083 hectares in the east of Kurdistan province, northwest of Iran. In this research, the data of 34 observation wells were used to investigate the condition of the underground water level and its depth fluctuations, and also to investigate the phenomenon of subsidence in region 8, the Sentinel-1 satellite image was used in the period (2014-2021). The research method includes statistical analysis of changes in the underground water level and interferometry of radar image. The results of the research showed that in the years 2014 to 2021, Dehgolan plain has subsided by -12 to -32 cm. In this way, an average of 6 centimeters of subsidence has occurred annually in these areas. The complete subsidence pattern of Dehgolan plain and the analysis of profiles and water level maps showed the center-west and southwest trends and the maximum subsidence is related to the central and western parts. Therefore, the conformity of the subsidence areas and the curves of the water table level drop, the use of underground water resources indicates that the withdrawal of more than the amount of aquifer nutrition has caused an increase in the effective stress in the sediments because the subsidence areas coincide with the areas of the groundwater level drop, or are located near them. In other words, this location adaptation in the high plains of Dehgolan shows that the cause of the subsidence of the high plains is the drop in the groundwater level, and as a result, the high plains are more vulnerable to the risk of subsidence.

This study is aimed at investigating and formulating strategies for the ecological restoration of the Khoshk River in Shiraz in the framework of sustainable urban development with a focus on flood management. Using an exploratory-correlative research method and library data, the most relevant literatures are reviewed and analyzed based on reliable historical documents, field observations, and remote sensing. These generates a theoretical model which identifies the effective ecological components and related strategies for urban river ecosystem restoration according to sustainable urban development framework. The model draws four stages of restoration including: river survey, strategy formulation, strategy implementation, , and monitoring and evaluation. The ecological components and sustainable urban development framework form a process-based structure that enables the assessment of the ecological conditions of the Khoshk River with emphasis on flood management to restore the river system. Effective strategies for the ecological restoration of the Khoshk River include integrated catchment management in the Shiraz basin, protection and restoration of its ecological habitat, preventing the transfer of pollution from sewage and urban runoff into the streambed, filtering pollutants naturally with phytoremediation, implementing water harvesting schemes, controlling river flow rate, restoring river morphology in particularly usable areas in the southern and south-eastern regions of Shiraz. In addition, conducting other measures such as enhancing ecological flow systems, storing water in various locations in the green-blue corridors of the Shiraz Khosh(dried)River, and unleashing the entire riverbed from it asphalt side roads, as well as developing regulations and land-use restrictions for river buffer zones are essential actions in mitigating and management if urban flood risks and intensity.