مجله مخاطرات محیط طبیعی
پیاپی 42 (زمستان 1403)

Environmental challenges are one of the most basic issues of today's city and the result of conflict and confrontation with the natural environment. A very important factor that has a decisive effect on the environmental sustainability of urban communities is the environmental governance of the city, which includes all policies, actions, plans, and executive programs in the territory of the city with environmental impact. The purpose of this research is to measure the challenges of environmental governance in Ahvaz metropolis. The research method is applied based on the purpose and descriptive-analytical based on the nature of the research. 18 indicators out of 25 indicators according to the ecological situation of the city were determined and a questionnaire was prepared. In this research, Shannon's entropy method was used to weigh the indicators and by using the Vicor model, the areas of the Ahvaz metropolis were ranked based on the governance challenges of the urban environment. The statistical community of this research, experts, experts, and managers of the environment, Abfa is the metropolis of Ahvaz. The sampling method is snowball and the data was collected using the researcher's questionnaire made this year. The findings showed that the components of domestic-commercial wastewater management (0.078), environmental infrastructures (0.074) are the most important, and magnetic pollutants (0.010) are the least important indicators and in prioritizing the regions, the eighth region is due to the establishment of factories and heavy industries and the company Drilling is facing the highest level of environmental pollution and challenges in industrial waste management. Also, the results have shown that the increase in environmental awareness among citizens and managers and the management of effluents, surface water, and waste are among the prerequisite drivers of environmental governance in different areas of Ahvaz city.

In recent years, population growth has led to the physical development of some cities in flood-prone areas. Among the cities that have faced this problem are those of Gotvand in Khozestan Province. Considering the importance of the topic, in this research, the process of physical development of Gotvand towards flood-prone areas was investigated. In this study, the SRTM 30-meter-high digital model, Landsat satellite images, and digital information layers were used as the most important research data. The most important research software includes ArcGIS, Expert Choice, ENVI, and IDRISI. AHP and LCM fuzzy logic models were used in this study. According to the desired goals, this research was conducted in three stages. In the first stage, flood-prone areas were identified. In the second stage, land use changes were investigated, and in the third stage, the development process of residential areas towards flood-prone areas was evaluated. Based on the results, a large part of Gotvand City, including its eastern areas, has high flood potential. The results of the analysis of satellite images have shown that the physical development process of this city has also increased towards flood-prone areas so that in 1992, about 1.1 square kilometers of the urban area was located in an area with very high potential. It has been estimated that this amount has increased to 1.3, 1.6, and 1.8 square kilometers in 2002, 2012, and 2022, respectively. Also, the results of the LCM model have shown that the size of residential areas on the floor with high flood potential will increase to 2.7 square kilometers by 2050. The population of Gotvand City faces life and financial losses due to flood risk.

Throughout history, human societies have continued to face dangers and have always suffered harmful effects. Environmental hazards are occurring not only in terms of number but also with an increase in diversity and amount of damage, especially in susceptible areas. Close connection with the environment, deprivation, lack of awareness, and preparation increases the vulnerability of coastal areas. However, they are inevitable phenomena and the only way to deal with them is to manage them. One of the approaches to facing environmental risks and crises is resilience. Mahshahr Port is exposed to various types of hazards and is in a highly vulnerable condition, and it is necessary to measure its resilience. The purpose of this research is to analyze resilience against environmental hazards in the 5 regions of Bandar Mahshahr. The current research is practical and descriptive-exploratory in terms of methodology. The tool used is a combination of researcher-made questionnaires. Questionnaires were distributed and completed in five areas of Bandar Mahshahr. Pearson's correlation coefficient and linear regression statistical tests have been used to analyze the relationship between factors affecting resilience. For descriptive items, the statistical methods of mode, median, mean, variance, skewness, and kurtosis have been used, and for weighting and determining the factors influencing resilience, multi-criteria decision-making methods (fuzzy hierarchical model) and ranking of resilience indicators have been used. The Waspas method has been used in the five areas of Mahshahr port. The results of the general state of resilience in the studied area, which is a function of its component indicators and variables, showed that the obtained average is lower than the average. The main reason for the poor state of resilience in the studied area can be attributed to the weakness of economic and physical indicators. Based on the weighting of the economic index, it was ranked first, which has a direct effect on resilience. The ranking of regions showed that Region 3 has a better situation than other regions.

There are very valuable habitats and ecological areas in Iran. One of these areas is Sistan and Baluchestan province, which is known as the habitat of the swamp crocodile, the only representative species of the order of crocodiles in Iran. Preservation of this valuable species and its environment in the conditions of global warming, consecutive droughts, and future climate changes requires planning and management of water resources. To achieve this goal, WEAP software was selected to simulate and model water resources in the Gwando protected area, and after simulating the geometry of the area, by defining eight scenarios, different management policies were investigated to optimize the use of water resources under climate change conditions. In this research, exponential micro-scale and production of meteorological data of the region under the influence of climate change in the future was done with the help of LARS-WG software. The results showed that with the continuation of the current conditions in the studied time horizon (twenty years), there is an unmet demand of 27.75 million cubic meters, which population growth and the continuation of geopolitical policies for the development of trade and industry will increase the intensity of tension and water demand in the region. Even the scenario of saving and managing water demand, although with a ten percent reduction in consumption, has an effect on reducing the amount of unmet demand, but it is not enough.

This research aims to evaluate the intensity of wind erosion and analyze the deposit processes in the Sistan Plain, focusing on two critical loci, Niatak and Jazink, covering approximately 131,660 hectares in southeastern Zabol, located in northern Sistan and Baluchestan Province in southeastern Iran. The key objectives of the research include providing appropriate solutions to minimize the damage caused by aeolian deposits and their secondary damage and identifying the hazards due to aeolian deposits in construction, agriculture, roads, and the damage incurred in the region. Wind-blown sand hazards as major natural threats in the Sistan Plain have increased in frequency and intensity in recent years. Due to climate change and the droughts of the past two decades, the vegetation cover has weakened in the research area, increasing its susceptibility to erosion. Therefore, it is essential to further evaluate the occurrence of this hazard and the resultant increase in vulnerability and associated financial and human losses. The research uses field studies, aerial photo analysis, satellite image evaluation over different periods, assessment of the regional general morphology and prevailing winds (120-day winds), geomorphological mapping of the area, as well as deposit sampling (sedimentology and related diagram plotting), and laboratory studies (X-ray diffraction (XRD), X-ray Fluorescence (XRF), and granulometry tests, morphoscopy, and statistical parameter determination). Comparative analysis and data analysis will be performed after conducting the relevant tests. Topographic maps, geological maps, and computer software such as ENVI and GIS were used in this research. The research results indicate that sand transport and prevailing wind directions are generally from northwest to southeast. This pattern, along with the centrality of existing dunes and 120-day winds, has the greatest effect on the region. Various factors such as strong and persistent winds, the flat and unobstructed nature of the plain, fine-grained soil, successive droughts, and poor vegetation cover play crucial roles in the extent of sand displacement across the Sistan Plain and the entry into the Chahnimeh reservoirs.

Zagros forests are one of Iran’s most valuable ecosystems, hosting diverse fauna and flora. Recent crises such as global warming, droughts, and dust storms have endangered this ecosystem, causing the weakening of individual trees or groups of trees in the region. Decline is an important disorder and challenge that threatens oak trees in the Zagros region. This study aimed to investigate the possibility of zoning decline-affected trees using machine-learning algorithms. The study area encompasses 101 hectares of middle Zagros forests known as the "Baloot Boland" region. Filed sampling was conducted to assess the health status of trees in 37 sample plots (1000 square meters each). In addition, the ground truth map was prepared on a tree-by-tree investigation basis for 11% of the total area. After analyzing reparability, three classes were selected for classification: "Class 1" representing areas with decline levels below 50%, "Class 2" representing areas with drought levels exceeding 50%, and "Class 3" including bare soil, sparse forest, roads, and rocky outcrops. The capabilities of the four machine learning methods, namely Maximum Likelihood, Neural Network, Random Forest, and Support Vector Machine, were compared. The results showed that the Maximum Likelihood method provided the highest overall accuracy and Kappa coefficients of 87.0% and 73.0%, respectively. Additionally, in Class 2, the area of decline was higher, indicating an increasing level of decline in the region. It is recommended to study the spectral behavior of trees directly during the decline process and to introduce suitable spectral indices to identify the early stage of decline-affected stands.

Currently, with the increase in aridity due to drought and climate change on the one hand, and the inefficiency of resource management on the other, we are witnessing a decrease in the water level of lakes or the complete desiccation of some lakes in Iran. Certainly, the weakening or destruction of this vital element (lakes) in the country's ecosystem will lead to the emergence of problems and hazards. Therefore, in the present article, an effort has been made to identify the hazards resulting from the drying trend of lakes in Iran and to present appropriate solutions to address these hazards from the perspective of experts (elites). Given the nature of this research, the Q-methodological approach was used to achieve the objectives. First, the changes in the water level of the country's prominent lakes over the past 20 years are reported. Then, through the analysis of document content and interviews with 14 expert specialists, 29 statements related to the hazards resulting from the drying of lakes were identified within 5 mental patterns. Additionally, 22 statements were obtained within 4 mental patterns regarding the appropriate solutions to address the drying of the country's lakes. The result is that the serious decline of the natural foundations in the surrounding ecosystem of the lakes is a consequence of this drying, which can create human-social challenges in the geographic space. Overcoming this situation primarily depends on the adoption of an integrated risk management approach to prevent ecosystem manipulation, continuous monitoring of Lake Desiccation, and the implementation of programs compatible with the human environment among them, we can mention the establishment of neighborhood management headquarters that have a direct relationship with the crisis management headquarters.

The purpose of this study is to determine the contribution of the maximum dust production capacity of 4 centers in the maximum dust production of Khuzestan province. According to the field information on soil texture and land use, the WRF-CHEM chemical model was used to simulate the occurrence of severe dust storms. To simulate the occurrence of a dust storm and estimate the maximum power of dust production at the peak of the activity of the dust system of four hypothetical centers in Khuzestan province, in addition to the dust concentration data of the environmental organization, in the verification of the event and the selection of the system from the data meteorological organization; Wind direction and speed and horizontal field of view were used. First, the simulation was done in real mode with full physics of the model, and in the next step, the amount of dust production and the role of each dust center in the centers were checked with the assumption of moistening of the surface layer of soil and ground. Among the 94 dust systems by defining the maximum event conditions, 39 main systems were selected. The results showed that each of the foci, on average and independently, caused an increase in dust and feeding systems that migrated to the region during the storms that occurred over two decades (2003-2018). The maximum contribution of each center was determined separately and simultaneously at the peak of the activity of the dusting systems. The results showed that at the peak of the activity of the dust collection systems, the maximum production capacity of source 1 (Horal Azim and North Khorramshahr) is 65.14% on average, source 2 (Mahshahr Center, Omidieh and Hindijan) is 59.91%, source 3 (East Ahvaz city) was 52.27% and source 4 (southeast of Ahvaz) was 55.74%. The total share of the average dust production in the four centers of the province is 62.94%, which if it is deducted from the amount of dust produced in the southern region of Khuzestan, which is 83.30% of the total dust in Khuzestan during the occurrence of different systems. , the remaining 20.36 percent, which is the share of unknown sources such as secondary sources that have the potential to produce dust or the dust created from them is the result of the discharge of major and larger sources. Knowledge of the contribution of each of the numerous dust centers in the Khuzestan Plain can help the decision-makers of operational plans to control internal fine dust centers.