مجله مخاطرات محیط طبیعی
پیاپی 35 (بهار 1402)

Shiraz, the largest city in the south of the country, is located in the highlands of Shiraz and has had many changes in different periods and continues to increase the urban area that this physical development without geomorphological studies and taking into account the limitations and risks Has been the result. Therefore, identifying areas prone to physical development by considering the limitations and geomorphological hazards is necessary for Shiraz's urban development. The purpose of this study is to identify suitable areas for the physical development of Shiraz city based on the geomorphological conditions of the region. In this study, using the fuzzy model, the final zoning map of urban development was prepared based on six effective parameters. Then, this map was evaluated based on geomorphological conditions and land use of Shiraz plain, and areas prone to urban development were suggested. The past decades have been subject to topographic conditions and there are many geomorphological hazards and limitations in the study area; About 48,000 square kilometers of the area, which is equivalent to 54%, is not suitable for the development of the city. There is a fault and only 17,000 square kilometers, which is equivalent to 19% of the area of the study area is suitable for the development of the city also according to the research results, the optimal location for the development of Shiraz is in the east.

Explanation:

 The post-metropolitan era can be called the era of the vulnerability of urban and rural settlements; because on the one hand, these settlements are facing natural hazards and technological crises, and on the other hand, they are facing security and social crises.

The present article is applied in terms of purpose and descriptive-analytical in terms of method. Collect data from the country's surveying organization, satellite images, etc., as well as to study and analyze data ARC GIS software, Dimatel model, and WASPAS software were used.

The results of the study show that of the area of 1037.64 square kilometers in Basht city, 150.80 square kilometers (14.53) is in the safe zone and 282.25 square kilometers (27.20%) is in the low-risk zone. 273.29 square kilometers equivalent to 26.33 percent in the middle zone, 233.20 square kilometers equivalent to 22.47 percent in the high earthquake risk zone, and also 98.20 square kilometers of the whole city equal to 9.47 in the very high earthquake risk zone. Also, the results of the earthquake risk showed that the city of Basht is located in a zone with a high earthquake risk. . Also, the results of the earthquake risk showed that the city of Basht is located in a zone with a high earthquake risk. Spatial analysis of the vulnerability of rural areas and settlements shows that 32.16% of settlements and villages of Basht city are in a very high-risk zone, 23.97% in a high-risk zone, 29.23% in a medium-risk zone, and 69.69 11% of rural settlements and settlements are in the low earthquake risk zone.

Therefore, taking necessary measures such as preventing the establishment, issuing permits and preventing construction on faults, public awareness of preventive measures before accidents, preventing the establishment and concentration of urban and rural settlements in high-altitude areas, establishing a warning system And timely warnings in pre-earthquake aftershocks, access of all urban and rural settlements to communication routes and relief centers for quick access to critical areas after the earthquake, etc. to reduce casualties and financial losses caused by the earthquake crisis in the city's population centers Basht seems necessary

floodways are one of the components of cities that act as natural drainage and protect the city from the risk of destruction by discharging runoff from torrential rains. Today, city managers try to take advantage of this natural capacity and plant trees, install urban furniture, create walking and cycling paths, etc. to create a fun and fresh environment and strengthen the sense of place of citizens to Increase their belonging and attachment to the environment and reduce the pressures of living in an urban environment. But in the meantime, care must always be taken that this double operation does not lead to a change in the basis and structure of the floodway and does not take it out of the initial user circuit. In the southern part of the city of Najafabad, there was a natural floodway that the municipality tried to organize and use more by implementing a plan. The purpose of this study was to investigate and analyze this plan based on the relationship between natural and human components of local identity and sensibility. This applied research has been done using library, field and survey methods and relying on descriptive and inferential statistics obtained from 360 questionnaires in the form of  SPSS20 software. The results show that in the implementation of this plan, more attention has been paid to the human components than the natural components. Since the sense of attachment to place formed in citizens is also more related to the human components, this implicitly indicates a kind of neglect of the natural use of this issue, which can lead to the formation of future risks.

Landslides move a huge volume of materials from a place to another place. Moreover, landslides may lead sediment to increase in Downstream of the basin which can be a threat to the populations and may cause erosion, in addition to affecting the landscape of the region. In this article, the landslide of Moallem-Kalaye in Alamut basin, one of the main sub-basins of the Shahroud, is investigated. The basis of the identification and studying of Moallem-Kalaye landslide is on field studies and Phenomenological interpretation. In this regard, in addition to the morphometry of different forms inside the landslide, the authors have climbed the surrounding heights and examined the role of related landforms in the happening of the catastrophic disaster. The topography prior to the landslide was rebuilt by the ArcGIS software and the result topography was analyzed against the current status. Next, the volume of the moved materials was estimated. The amount of the materials extracted in the landslide, by raster calculation in ArcGIS. The landslide of Moallem-Kalaye with the width of 1.3 kilometers (the crown part of the landslide), the longitude of 1.6 kilometers, and the average depth of 80 meters has taken place in the conglomerate of the Andj, which has moved a sum of 91 million cubic meters. The existence of a conglomerate with a very steep slope and marl filled with water, has led a wide area of materials to move. The area of the surface of failure has been roughly 2.632 square kilometers, the materials have scattered on a surface of more than 13.5 square kilometers. Findings show that weaker landslides in the upper side, ruins the hydrological situations of the lower side, regions and provides the grounds for huge landslide.

The vulnerability of informal settlements to environmental hazards reveals the importance of paying attention to resilience. Resilience is considered a form of foresight due to the dynamic nature of society's response to risks. Accordingly, this issue is one of the ways to reduce risk and vulnerability in human settlements. This research has been carried out to identify physical factors affecting the creation of resilient neighborhoods in the areas involved with informal settlements in Hamedan city against environmental hazards. The research indicators were evaluated in five spectrums of user index, density index, access index, physical structure index, and road network. The present research method is practical in terms of its purpose and descriptive-analytical in terms of its nature and method, and to collect information and data, documentary and field method (questionnaire) has been used. The results show that the level of resilience of informal settlements in Hamedan city is lower than the average level and the first factor i.e. building resistance has the biggest role in explaining the improvement of resilience of informal settlements in Hamedan city. This factor can be successful in dealing with and adapting to resilience. Among the identified factors, the density factor does not affect improving the resilience of informal settlements, and other factors have a direct and positive effect.

Precipitation is one of the most important and variable elements of climate that has a lot of spatiotemporal variability, especially in arid and semi-arid regions. Adequate knowledge of precipitation variations is crucial for agricultural planning and water resource management in any region. For this purpose, in this study, using the daily data of Asfezari precipitation database during the period 1349 to 1394, the characteristics of precipitation and also the precipitation trends in Yazd province were investigated. The average coefficient of variation of the total annual rainfall of the province was 42.2 and varied from 32.9 to 68.4 in different cells. The highest coefficient of variation of precipitation on an annual scale was observed in the central and western regions of the province, which indicates the greater dispersion and risk of precipitation in these regions. The trend of precipitation was examined using nonparametric statistical tests of Mann-Kendall and Sen’s slope estimator. The spatiotemporal distribution of the trend of total annual Precipitation and total annual extreme Precipitation was similar and in both cases the general trend of the province was decreasing. The highest share of extreme Precipitation in total annual Precipitation was observed in the central regions of the province (Yazd-Ardakan plain). Therefore, in rainy years, these areas have favorable conditions for severe floods.

Floods are one of the largest and most common forms of natural hazards, and identifying areas prone to floods is one of the basic measures in natural resource management and development planning. Therefore, the aim of the present study is to zoning the basin upstream of the Soltan Meshkinshahr Bridge Hydrometric Station in terms of flood potential. To achieve this goal by field studies and resource review, first 11 effective factors of flood occurrence in the region including slope, dem, lithology, distance from the fault, precipitation, land use, distance from the river, flow velocity, flow time and soil, were identified and extracted in GIS environment. The standardization of the maps was done using the fuzzy method and then in order to weight the proposed criteria, the CRITIC method was used and the final analysis and modeling was performed using the Aras model. The results showed that the factors of slope, lithology, land use and dem were by weight values, respectively; 0.164, 0.156, 0.118 and 0.116 have the greatest impact on flooding in the study area. Also, according to the results, 20.46 and 32.02 square kilometers of the area, respectively, are in a very high-risk and high-risk category, which indicates the high potential of this basin for floods. The results also showed that the time required for water to flow to the outlet varies from 0 seconds (rain falling on the outlet itself) to 68,000 seconds (over 17 hours). In this case, smooth areas near the basin with the highest time and lowest speed and also in the pastures on the northeast side with the lowest time and highest speed reach the watershed exit point. Therefore, flood risk zoning can be effective in carrying out conservation, watershed management and management measures in this basin.

Khorramabad-Pol-e-Zal freeway is one of the mountainous and high-risk routes that need to study the risk of rockfall. Therefore, the present study was conducted to investigate and zone the risk of rock fall on the Khorramabad-Zal freeway in 1400. In this study, fuzzy-gamma and AHP multi-criteria decision-making methods were used to prioritize and weigh the criteria. All studied layers and sub-layers include: land use, distance from faults, average rainfall, distance from waterways, distance from roads, slope classes, slope direction, lithology, and digital elevation model (DEM) They were weighed using the fuzzy-gamma method and ranged from 0 to 1 and Fuzzy layers with gamma value (γ) of 0.95 were combined and maps of areas prone to rock fall in the study area were obtained. Then, using the AHP method, areas at risk of rock fall Khorramabad-Pol-e-Zal freeway were identified. The results of the AHP method showed that the distance from the road with a weight of 0.1633 and the rock material with a weight of 0.1621 is the most important principles for measuring the risk of rockfall. The results showed that the Hierarchical Analysis (AHP) method compared to the fuzzy-gamma method identified areas more prone to rock fall risk, which indicates the higher accuracy of this method compared to the fuzzy-gamma method.

Evaluating the impact of climate change on the planning of optimal allocation of water resources in Kohgiluyeh and Boyer-Ahmad Abstract In recent years, reduction of precipitation following climate change had undesirable effects on various sectors, especially water resources in the province. For Manage these conditions requires recognizing the two dimensions such as, climate behavior and the optimal and efficient allocation of water resources in important and consumer sectors such as agriculture. In this research, investigate climatic behavior and climate change prediction with approach of evaluating dry spells in the middle decade based on the emission scenario RCP4.5 and HadGEM2-ES Model for the province. Identified High risk areas under the influence climate oscillation. Then, for the control and optimal allocation of water resources in the catchment area in the province, using the Compromise Programming method (CP), the first step extracted and weighted allocation criteria, and finally done analysis sensitivity to climate change. Ration each regions of surface water availability allocated. The results showed that with considering the climatic state and sensitivity analysis of the model from an average of 12 billion m3 of surface storage, areas such as Yasuj and Sisakht with increasing the length of dry spells in the future and, they have a larger share in the final optimal allocation values (33% and 19%). In contrast, in hot and dry areas such as Basht, Charam and Gachsaran Because of lower sensitivity, received the lowest optimal allocation values with 6, 7 and 10% in all of the final allocation.