Geomorphology
sayyad Asghari Saraskanroud; Aghil Madadi; nazfar aghazadeh; Raoof Mostafazadeh
Abstract
Soil erosion is one of the significant environmental challenges that leads to the degradation and decline of soil quality. This study examines the impact of land use changes on soil erosion in the Givi Chai region. The use of satellite images (ETM+7 2010 and OLI 2022) as the primary tool for analyzing ...
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Soil erosion is one of the significant environmental challenges that leads to the degradation and decline of soil quality. This study examines the impact of land use changes on soil erosion in the Givi Chai region. The use of satellite images (ETM+7 2010 and OLI 2022) as the primary tool for analyzing land use changes and assessing soil erosion has been a crucial step in this research. The images were classified using an object-based method, identifying various land uses. These uses included residential areas, agricultural lands, barren lands, orchards, dense, medium, and sparse vegetation, and water bodies. The factors influencing the G2 model included R (rainfall), S (soil erodibility) , V (vegetation cover), T (topography) , and I (slope adjustment factor). An erosion map was created and analyzed. Results indicated an increase in residential areas and sparse vegetation while showing a decrease in orchards and medium vegetation cover. These changes directly impacted soil erosion. The amount of erosion in 2022 increased compared to 2010, with the highest erosion occurring in agricultural and barren land uses. The final erosion map indicated areas with very high and high erosion associated with agricultural land use, weak pastures, and residential areas. The increase in agricultural and barren lands and the decrease in vegetation cover were identified as the main factors contributing to soil erosion. The study shows that changes in land use, particularly the increase in residential and agricultural areas, have a negative impact on soil erosion.
Geomorphology
Mousa Abedini; Mahrokh sardashti
Abstract
In recent years, the Kandovan-Chalus axis in the north of the country (in Mazandaran province) has experienced numerous dangerous floods. Geological and topographic features, precipitation and human intervention have made the Kandovan-Chalus axis susceptible to potential flood risks. In addition to natural ...
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In recent years, the Kandovan-Chalus axis in the north of the country (in Mazandaran province) has experienced numerous dangerous floods. Geological and topographic features, precipitation and human intervention have made the Kandovan-Chalus axis susceptible to potential flood risks. In addition to natural factors; lack of dredging, lack of proper watershed management and unprincipled human interventions have led to an increase in flood risks in the researched area. The aim of this research is to zone flood-prone areas and determine the priority of factors affecting their occurrence using the random forest algorithm in the Kandovan-Chalus axis. For this purpose, 9 land use indicators were selected: distance from the river, slope, height, failure to observe the river boundary, river discharge, waterway network, rainfall, and lack of river dredging. After determining the variance inflation factor and tolerance coefficient, in the next stage, modeling was carried out by entering the data related to the effective factors into the ARC/MAP10.2 software. Then, the random forest algorithm was used to determine the role of the effective factors in the occurrence of floods in the region. Finally, a flood risk zoning map was prepared in three very dangerous, medium-risk, and low-risk zones in the ARC/MAP10.2 environment. The results show that based on the flood potential map, the risk of flooding in the region is about 261.43 square kilometers of the region, 151.1 square kilometers of the region are considered low-risk areas, 118.3 square kilometers of the region are considered medium-risk areas, and about 118.3 square kilometers
Geomorphology
بهناز سلیمانی; maryam ilanloo
Abstract
Understanding the river's changes and displacements in the past decades is essential for future planning. Using remote sensing facilities, satellite images, and aerial photographs, these goals can be achieved at minimal cost and in the shortest possible time. The aim of this study is to zone the ...
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Understanding the river's changes and displacements in the past decades is essential for future planning. Using remote sensing facilities, satellite images, and aerial photographs, these goals can be achieved at minimal cost and in the shortest possible time. The aim of this study is to zone the temporal and spatial changes of the riverbed using satellite images in the Arc/Map software environment. Landsat satellite images from 1973, 1986, 1999, 2012, and 2024 were used to examine and monitor the temporal and spatial changes of the Bahmanshir River. The river was divided into six different intervals and the changes were zoned in seven classes: high sedimentation, medium sedimentation, low sedimentation, stable, low erosion, medium erosion, and high erosion. The results showed that in all periods except the 1999-2012 period, the sedimentation rate prevailed over the erosion rate. In all periods except the 1999-2012 period, the sedimentation rate prevailed over the erosion rate. The largest changes occurred in the first period during the period 1999-2012, in the second, fourth and fifth periods during the period 1973-1986, and in the third and fifth periods during the period 2012-2024. Considering that in all the periods studied except the period 1999-2012, sedimentation prevailed over erosion, only in the first period did erosion exceed sedimentation.
Geomorphology
farhad khodamoradi; Shahram Roostaei; Ali Zareiyan
Abstract
Landslides are influenced by internal, external (climatic), and anthropogenic factors. Salavatabad Pass, located in eastern Sanandaj along the Sanandaj–Hamedan route, is a highly vulnerable area experiencing recurrent landslides. The presence of the main road, along with uncontrolled construction, ...
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Landslides are influenced by internal, external (climatic), and anthropogenic factors. Salavatabad Pass, located in eastern Sanandaj along the Sanandaj–Hamedan route, is a highly vulnerable area experiencing recurrent landslides. The presence of the main road, along with uncontrolled construction, gardening, and road construction, has exacerbated these hazards. This study aims to identify, quantify, and classify continuous slope movements using radar interferometry and land use analysis. To assess vegetation cover, the NDVI index was derived from eight Sentinel-2 images, aiding in the selection of appropriate radar imagery. Additionally, four Sentinel-1 images from 2020 to 2023 were processed in SNAP software to analyze surface displacements. The land use map was generated using a 2023 Landsat-8 image, with supervised classification applied in ArcGIS, categorizing the area into six classes. The results indicate an annual displacement of 2.4 cm, totaling 9.5 cm over the study period. Hazard zoning revealed that 14.45% of the area falls within the high-risk category, while 29.33% is classified as moderate risk. The road network was divided into three segments, with the first (6.59 km) and second (6.6 km) segments classified as high and moderate risk, respectively. Ultimately, 18 unstable zones were identified along the road, with 16 primarily associated with rangeland and barren land use. The highest displacements were observed on slopes with northern, northwestern, southern, and western aspects..
Geomorphology
Mohamad Sharifi Paichoon; Leila Moosavi
Abstract
Flooding, while a natural phenomenon that contributes to the formation of fertile plains and agricultural terraces is now recognized as one of the most significant natural disasters globally. This research examines the key factors influencing flooding, assessing their significance and impact across different ...
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Flooding, while a natural phenomenon that contributes to the formation of fertile plains and agricultural terraces is now recognized as one of the most significant natural disasters globally. This research examines the key factors influencing flooding, assessing their significance and impact across different areas of the Hor Roud catchment. Initially, critical indicators such as precipitation, soil, lithology, land use, drainage networks, elevation, slope, and slope direction were identified, mapped, and organized into information layers. These layers were converted into raster format and reclassified. To refine the data, a fuzzy logic approach was applied, utilizing linear and triangular functions based on the properties and effects of each layer. The fuzzy layers were then combined using gamma (0.9) operators. Additionally, the TOPSIS technique was employed to pinpoint the most influential indicators within the basin’s spatial zones. The final results, obtained from a fuzzy logic map and a TOPSIS technique, indicated that distant to the main stream, lithology, and land use were the most influential factors contributing to flooding in the Hor Roud catchment. The maximum flooding occurs along the banks of the main rivers, where conglomerate, marl, and clay soils cultivated. The flood risk map identified key contributing factors: slopes between 0-10%,, elevations of 1500-1800 meters, hydrological group D soils, cultivated land, conglomerate rock formations, proximity to main streams , and annual precipitation levels between 800-800 millimeters. The findings revealed that distant to the main stream, lithology, and land use were the most significant factors driving flooding in the Hor Roud catchment.
Geomorphology
Leila Aghayari; sayyad Asghari Saraskanroud; Batool Zeinali
Abstract
The aim of the present study is to investigate the changes in different land uses and evaluate the effects of land use changes on soil erosion in Namin County. In order to achieve the goals of this study, first a land use map was prepared using the object-oriented method for the two periods of 2002 and ...
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The aim of the present study is to investigate the changes in different land uses and evaluate the effects of land use changes on soil erosion in Namin County. In order to achieve the goals of this study, first a land use map was prepared using the object-oriented method for the two periods of 2002 and 2024. In the next stage, information layers of other effective factors for soil erosion of the city were prepared in the GIS environment. The evaluation and standardization of the layers were carried out using the fuzzy membership function and weighting of the criteria, using the CRITIC method. The final analysis and modeling was carried out using the ARAS multi-criteria algorithm. The results of this study showed that the largest area in 2002 was related to poor pastures and rainfed agriculture, with 493.71 and 209.91 square kilometers, respectively, and in 2024, it was related to poor pastures and rainfed pastures with 422.62 and 271.93 square kilometers, respectively. According to the 2002 erosion zoning map, 15.05 and 22.46 percent, respectively, and according to the 2024 erosion zoning, 15.92 and 25.04 percent of the county's area are in the two very high-risk and high-risk categories, respectively. In general, the presence of erodible soil, the occurrence of heavy rainfall, and the intervention of human factors through land use change, destruction of vegetation, excessive grazing, road construction, plowing on slopes, and improper irrigation can be considered as the major factors of soil erosion and reduced fertility in Namin City.
Geomorphology
Arezou Cheraghi; Shahram Bahrami; Somayeh Khaleghi; Kazem Nosrati
Abstract
Dolines as karst landforms play an important role in soil formation. In this study, the morphometry of dolines and their relationship with the physicochemical characteristics of soil in Noakoh Anticline in Kermanshah province were evaluated. Chemical and physical characteristics of 36 soil samples of ...
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Dolines as karst landforms play an important role in soil formation. In this study, the morphometry of dolines and their relationship with the physicochemical characteristics of soil in Noakoh Anticline in Kermanshah province were evaluated. Chemical and physical characteristics of 36 soil samples of dolines were collected and measured in the laboratory. Also, digital elevation model (DEM; 13 cm) obtaining from UAV images, was used to measure the morphometric parameters of dolines. Pearson’s correlation and T-tests were performed on data using SPSS software. Results showed that large dolines have higher slope, depth and roundness, as well as sandy soils, and higher EC, pH, potassium, phosphorus, water holding capacity and soil organic carbon. Also, low- elevation dolines have higher values of area, slope, depth, roundness, and host soils wih higher EC, PH, potassium, water holding capacity, organic carbon, and saturation percentage than high elevation dolines. The dolines located in the plunge of the anticline have higher values of area, slope, depth, roundness and cntain soils with higher values of clay%, EC, PH, potassium, water holding capacity, organic carbon and saturation percentage than the dolines in the central part. The mean of the most morphometric parameters and physicochemical characteristics of the soil in steeper-slope dolines is higher than in low-slope dolines. Therefore, the morphometric and pedological differences of dolines show that their formation and evolution are more at lower altitudes, plunged areas and steeper slopes. In general, vegetation, elevation, slope and type of precipitation play an important role in morphometric differences and soils in dolines.
Geomorphology
maryam bayatikhatibi; imad ali
Abstract
The Quetta sub-basin is a part of the Pishin River basin, situated in the southwestern region of Pakistan. This study aimed to determine the spatial distribution of annual soil erosion through the utilization of the Revised Universal Soil Loss Equation (RUSLE) model. To accomplish this, numerous data ...
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The Quetta sub-basin is a part of the Pishin River basin, situated in the southwestern region of Pakistan. This study aimed to determine the spatial distribution of annual soil erosion through the utilization of the Revised Universal Soil Loss Equation (RUSLE) model. To accomplish this, numerous data mining techniques were employed, along with machine learning algorithms, to produce thematic layers (K, R, LS, C, and P) that served as input parameters for the RUSLE model. According to the resultant model, soil erosion in the study area ranged from 0.00 to 866 tons per hectare per year. The estimated values for rainfall-runoff erosivity (R), soil. erodibility (K), topography (LS), and cover management (C), factors ranged from 147 to 191 (MJ.mm.ha⁻¹.h⁻¹year⁻¹), 0.0229 to 0.0259 (t.ha.MJ⁻¹mm⁻¹), 0.002 to 360.77, and 0.001 to 1, respectively. The statistics revealed that 58% of the land in the study area experiences a very low degree of soil erosion, at an erosion rate less than 13.58 t/ha/year. About 24% of the study area faces low erosion, with an erosion rate spanning from 13.58-44.16 t/ha/year. 13% of the area is demarcated as moderate soil erosion severity, at an erosion rate ranging from 44.16-81.53.14 t/ha/year. On the other hand, 5% of the study area experienced high to very high soil erosion, with an erosion rate of 81.53-866.34 t/ha/year.
Geomorphology
sayyad Asghari Saraskanroud; Fariba Esfandyari; Mehdi Faal Naziri; Batool Zeinali
Abstract
Land subsidence refers to the gradual or sudden lowering of the earth's surface as a result of various factors such as tectonic activities, mining, oil and gas fields, and illegal extraction of underground water. In Alborz province, the growing trend of population and migration in recent years has added ...
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Land subsidence refers to the gradual or sudden lowering of the earth's surface as a result of various factors such as tectonic activities, mining, oil and gas fields, and illegal extraction of underground water. In Alborz province, the growing trend of population and migration in recent years has added to the increase in demand and the amount of water withdrawal from the underground water table, so it is subject to subsidence due to the sharp drop in the level of underground water. In this research, subsidence was first evaluated using the radar interferometric technique, and then, prone areas were zoned with a multi-criteria algorithm in the time frame of 2016 and 2023. The results of information extraction with interferometric technique showed that the average amount of subsidence in the urban boundaries of Saujblag, Karaj, Nazarabad, Chaharbagh and Fardis is between 15 and 320 mm. According to observations, the highest amount of subsidence is in the eastern part and then in the southern and southwestern parts. According to the estimated results of subsidence risk zoning; The parameters of water level drop, land use, slope and geology, respectively, with weight coefficients of 0.16127, 0.141875, 0.130145 and 0.128474, are the most important factors in creating the risk of subsidence in the study area, which are 31 and 23%, respectively. From the range, it has a very high and high probability of danger. Finally, it can be said that the most important factor in subsidence in the studied area is excessive use of underground water and the drop in water level. In some urban areas, such as Hew and Goch Hesar, Malekabad-Mehrshahr-Mehrvila-Kamalshahr, and Mohammadshahr, the highest risk of subsidence can be seen.
Geomorphology
Reza esmaili; Niusha Nourizadeh Nesheli
Abstract
Rivers are natural systems that have undergone significant changes in their morphology due to human pressures over the past decades. The factors influencing river morphological changes and their responses vary across different regions. Consequently, in the present study, morphological changes in a section ...
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Rivers are natural systems that have undergone significant changes in their morphology due to human pressures over the past decades. The factors influencing river morphological changes and their responses vary across different regions. Consequently, in the present study, morphological changes in a section of the Haraz River in of Amol city were investigated over a 53-year period (from 1968 to 2021).The changes in river width, planform, and riverbed landforms were examined using aerial photographs and satellite imagery. Subsequently, by calculating the specific stream power and conducting field observations, the hazards associated with the river channel were identified. In 1968, the average river width was measured at 141 meters, but by the years 2006 and 2021, it had decreased to 55 meters. The area of riverbed landforms, including the active riverbed and longitudinal bars, decreased by 50% and 95%, respectively, during this period. The river channel transitioned from a braided pattern to a single-channel pattern due to channel narrowing and significant reduction in longitudinal bars. These changes led to an increase in stream power and erosional processes, resulting in river incision and bank erosion. Key factors contributing to the morphological alterations in the study area included the reduction in base flow, irrigation channel diversion, and land use changes along the river margins. Considering the observed trends, the construction of a new dam (Haraz Dam), continued exploitation of floodplain areas, and channelization could exacerbate the risks associated with the river channel and lead to significant floods.
Geomorphology
Fariba Esfandyari Darabad; Ghobad Rostami; Raoof Mostafazadeh; Mousa Abedini
Abstract
In the current study, the risk of landslides in the Zamkan Watershed, located in Kermanshah Province, was evaluated. Two machine learning models, Support Vector Machine (SVM), and Logistic Regression, were used to prepare a landslide susceptibility map. Toward this, 13 informational layers including ...
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In the current study, the risk of landslides in the Zamkan Watershed, located in Kermanshah Province, was evaluated. Two machine learning models, Support Vector Machine (SVM), and Logistic Regression, were used to prepare a landslide susceptibility map. Toward this, 13 informational layers including elevation, slope, aspect, Melton ruggedness number, terrain convexity, stream length, valley depth, topographic wetness index, precipitation, geological formations, distance from rivers, distance from roads, and vegetation cover were utilized as independent variables. Approximately 70% of the watershed's landslide pixels were used for model training, and 30% for model validation. Model validation was performed using ROC curves. The results indicated the higher performance and accuracy of the radial basis function (RBF) kernel of the SVM model for generating landslide hazard maps in the study area. The area under the curve (AUC) for the RBF kernel was approximately 0.951 for model training and 0.944 for model testing. The results suggest that slope with a coefficient of 0.28, precipitation with a coefficient of 0.27, lithology with a coefficient of 0.26, and elevation with a coefficient of 0.22 are the main controlling factors for landslides occurrence in the Zamkan Watershed. Both the SVM model and logistic regression confirmed the deterministic effects of selected factors on landslides. About 35% of the study area as classified as highly susceptible to landslides, primarily in the eastern half of the watershed. Factors such as high elevation, steep slopes, heavy precipitation, and the Kazhdomi Formation's composition were identified as key contributors to this susceptibility.
Geomorphology
Gholam hassan jafari; zinab barati
Abstract
The analysis of some geological features and structures can be used to determine Quaternary developments. Analyzing the types of landslides, their density, and scale is the key to identify the evolution of landforms. Based on this, the current research was carried out with the aim of spatial analysis ...
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The analysis of some geological features and structures can be used to determine Quaternary developments. Analyzing the types of landslides, their density, and scale is the key to identify the evolution of landforms. Based on this, the current research was carried out with the aim of spatial analysis of landslides that occurred in different lithologies of Mo’alem-Kelayeh basin, a part of eastern Alamut basin, between the longitudes 50°26'00″ to 50°31'20″ and the latitude 36°22'00″ to 36°30'00″, based on topographical, geological conditions, vegetation, the condition of waterways, and the proximity of different rocks in the area. According to the results, the Karaj, Rute, Shamshek and Neogene and destructive sediments are the most erodible formations in the studied area, which are the most important factors involved in the occurrence of mass movements on a micro and macro scale under the Mo’alem-Kelayeh basin. The nonresistant lithology is more extensive in the geographical levels downstream of the rivers. In such areas, in addition to the loosening of the lithology in wide sections, the material and energy flowing in the river also increases, if due to the lower slope of the slopes, the effect of the river on movements of the slopes becomes more limited. In the terrestrial levels close to the ridge line, matter and energy are less and lithology is more resistant; But due to greater slope of the slopes and the involvement of physical weathering in the porosity of rocks, the effect of river on the occurrence of surface slope movements increases.
Geomorphology
leila aghayary; sayyad Asghari Saraskanrood; Batool Zeynali
Abstract
Text Landslides are one of the types of large-scale processes that cause many human and financial losses in many parts of Iran and the world every year. The increase in population and the expansion of human settlements in mountainous areas, the difficulty of predicting the occurrence of landslides ...
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Text Landslides are one of the types of large-scale processes that cause many human and financial losses in many parts of Iran and the world every year. The increase in population and the expansion of human settlements in mountainous areas, the difficulty of predicting the occurrence of landslides and the numerous factors influencing the occurrence of this phenomenon, reveal the necessity of landslide risk zoning. Identifying the effective factors in the occurrence of this phenomenon and its risk zoning is one of the basic and practical methods to achieve its forecasting, control and monitoring solutions. By using field studies, geological and topographical maps, and by reviewing the researches and studies done in this field, as well as examining the existing conditions in the studied area, 9 factors of elevation, slope, slope direction, lithology, distance from the fault. , the distance from the river, the distance from the communication roads, land use and rainfall were investigated as factors affecting the occurrence of landslides. Therefore, the purpose of this research is to investigate and analyze the most important factors involved in creating the risk of landslides in Garami city and to identify the prone areas that will probably be involved in landslides in the near future. In this research, the zoning of prone areas was done with the Aras multi-criteria algorithm in the Edrisi software environment, and according to the results of landslide risk zoning; The criteria of land use, slope, and lithology are the most important factors involved in creating the risk of landslides in the study area with weight coefficients of 0.187, 0.152, 0.152, and 0.142, respectively, and are 361.99 and 450.32, respectively. A square kilometer of the area has a very high probability of danger. Finally, it can be said that the most important factor involved in increasing the amount and potential of landslides in Germi city is the change of land use and the increase of agricultural land and livestock pastures.
Geomorphology
Jamshid Yarahmadi; Mohammad Khosroshahi
Abstract
The extended periods of drought, decrease in vegetation, and enlargement of the salt playa at Lake Urmia have resulted in the formation of local dust hotspots on the periphery of Lake Urmia in East Azarbaijan province. The objective of this study was to examine the spatial and temporal distribution of ...
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The extended periods of drought, decrease in vegetation, and enlargement of the salt playa at Lake Urmia have resulted in the formation of local dust hotspots on the periphery of Lake Urmia in East Azarbaijan province. The objective of this study was to examine the spatial and temporal distribution of wind erosion in East Azarbaijan province using the DSI index. To achieve this, a set of weather data recorded over the past 30 years at specific codes in meteorological stations was compiled. Subsequently, the Mann-Kendall test was employed to assess the presence of a trend in the data series. Following this, the frequency of dust storms was calculated using the DSI index, and a spatial distribution map was generated in the GIS. The results of the Mann-Kendall test indicated that the slope of the trend for both local and extra-local dust storms in the province is on the rise. However, only the trend in extra-local dust storms is statistically significant at the 95% confidence level. The findings of the research revealed that the majority of the observed dust storms originate from outside the local area in East Azarbaijan province. Nevertheless, there has been a relative increase in the frequency of local dust storms in recent years, which can be attributed to the prolonged droughts resulting in reduced vegetation and the expansion of the playa of Lake Urmia. In this context, the highest frequency of dust storms has been observed at the Tabriz, Sahand, and Maragheh meteorological stations near Lake Urmia.
Geomorphology
Maryam Bayati Khatibi; Behrooz Sari Sarraf
Abstract
Today, following the drying up of Lake Urmia, new centers for wind erosion activity have been formed in the northwest of the country, and these centers have become the source of dangerous dust production. In the southeastern part of Lake Urmia, the formation of wind erosion centers can lead to irreparable ...
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Today, following the drying up of Lake Urmia, new centers for wind erosion activity have been formed in the northwest of the country, and these centers have become the source of dangerous dust production. In the southeastern part of Lake Urmia, the formation of wind erosion centers can lead to irreparable damages from the point of view of nature and human health. In this study, in order to identify wind erosion centers, changes in the water level of Lake Urmia based on the fluctuation pattern of climatic parameters using data The long-term effects of the existing stations in the Urmia Lake watershed were investigated. In order to identify the origin areas of fine walnut production and track dust storms in the studied area, horizontal visibility data below 1000 meters of meteorological data and Lagrangian HYSPLIT model in retrograde mode were used at different stations and at different levels of the atmosphere. It was used regularly and also the highest amount of dust containing 26 pressure tsars (100-1000 hectopascals) and available with a time step of 12 hours. At the same time as the first dust entered the study area, the wind direction was investigated for 24 hours before that. In the studied area (Banab and Malekan cities), the focus of wind erosion was investigated using AOD data from MACC database with a spatial accuracy of 0.125 × 0.125 geographic degrees and a daily time scale. In this study, MODIS Terra and Aqua satellites with a wavelength of 550 nm were used to generate AOD data. Day-by-day review of MODIS satellite images and the implementation of the fine dust characterization index revealed the occurrence of specific dust storms over Urmia Lake and southeast of the lake on different days. Investigations showed that extensive salt dust spreads in all parts of Lake Urmia, including the southeast of the lake in the limits of Bonab city, and the dust in this part is spread in the bed of atmospheric currents to the east and southeast for a distance of more than 140 km. In the northeast direction, they spread over 150 km in 12 hours.
Geomorphology
Mousa Abedini; AmirHesam Pasban
Abstract
Soil erosion is one of the serious environmental threats that can affect the political, social and economic aspects of countries. One of the widely used experimental models for estimating the amount of soil erosion is the modified global soil erosion equation known as the RUSLE model. The purpose of ...
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Soil erosion is one of the serious environmental threats that can affect the political, social and economic aspects of countries. One of the widely used experimental models for estimating the amount of soil erosion is the modified global soil erosion equation known as the RUSLE model. The purpose of this research is to analyze and zonate the amount of soil erosion and its relationship with hydrogeomorphic indicators and vegetation cover of Khiavchai Meshkinshahr watershed in Ardabil province. RUSLE model factors include rain erosion (R), soil erodibility (K), topography (LS), vegetation (C) and protection operations (P). respectively, by using rainfall data, soil texture layer, digital model of height and land use were prepared in the environment of geographic information system (GIS) and after overlapping the layers, the amount of annual soil erosion between 0 and 150.54 tons per hectare per year in The area level was estimated. In the next step, the hydrogeomorphic and vegetation indices that are effective in soil erosion include topographic moisture index (TWI), waterway capacity index (SPI), domain curvature index (Curvatore), section curvature index (Profil Curvatore), surface curvature index (Plan) Curvatore) and Normalized Vegetation Index (NDVI) were created in ArcMap environment and zoning maps were prepared. The results of this research also showed that the topography factor with a correlation coefficient of 0.92% had the greatest impact on the estimation of annual soil erosion by the RUSLE model. In another study, the relationship between hydrogeomorphic indices and vegetation cover with annual soil erosion rate was conducted, and the results showed that normal vegetation cover indices and cross-sectional curvature were the most and least effective with correlation coefficients of 0.57 and 0.05, respectively, compared to other indices.The results of this research confirm the possibility of combining the effective indicators of hydrogeomorphic and vegetation on erosion, as well as the possibility of using other effective indicators and the capabilities of RS and GIS to quantitatively estimate the amounts of soil erosion.
Geomorphology
Davoud Mokhtari; Mohammad Hossein Rezaei Moghaddam; diana dortaj
Abstract
Tectono-karst processes play an important role in the formation and change of landforms. Some areas, such as Zagros in Fars province, are affected by tectono-karst activities due to being in a tectonically active area and also having karstic formations. Due to the importance of studying landform changes ...
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Tectono-karst processes play an important role in the formation and change of landforms. Some areas, such as Zagros in Fars province, are affected by tectono-karst activities due to being in a tectonically active area and also having karstic formations. Due to the importance of studying landform changes in different planning, in this research, the analysis of tectono-karst processes in the formation and expansion of the transverse valleys of Zagros, Fars, from the range of Avaz to Karmostaj has been done. In this research, Sentinel 1 radar images, SRTM 12.5m high digital model, 1:100000 geological map of the region and hydroclimatic information of the region are used as the most important research data. The most important tools used in the research were ArcGIS and GMT. This research has been carried out in two stages according to the desired goals, in the first stage, the tectonic status of the region has been evaluated using the SBAS time series method, and in the second stage, using the Fuzzy Logic-AHP integrated model, to the potential The measurement of areas prone to the development of karstic processes has been discussed. The results obtained from the SBAS time series method have shown that some of the transverse valleys of the region are subsiding in comparison to their downstream regions, and this problem has caused a decrease in the height difference, a decrease in the speed of runoff, creating the necessary opportunity for erosion and dissolution, and in The result is the transverse development of these valleys. Also, based on the results, all the transverse valleys are located in the category with high or very high potential for the development of karstic processes, which indicates the role of karstic processes in the formation of transverse valleys in the region. The total results of this research have shown that the formation and development of transverse valleys in the studied area were affected by tectokarst factors.
Geomorphology
Naimeh Rahimi; Somaiyeh Khaleghi; Alireza Salehipour Milani
Abstract
In the east of Jask City, four severe floods with high discharge occurred in the Sadij River between 2009 and 2019. This research aims to evaluate the morphological changes of the Sadij River due to the occurrence of floods over a period of 11 years and in the four significant floods during 2009, 2014, ...
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In the east of Jask City, four severe floods with high discharge occurred in the Sadij River between 2009 and 2019. This research aims to evaluate the morphological changes of the Sadij River due to the occurrence of floods over a period of 11 years and in the four significant floods during 2009, 2014, 2017, and 2019. Geomorphic effects on the river were extracted using Landsat and Google Earth satellite images. GIS10.5 software and the Fluvial Corridor were used to investigate the morphological changes caused by floods in the river. The erosion and sedimentation levels were evaluated with the RNCI model. The results showed that the average width of the channel decreased by about 38 m, and the length of the river increased by about 3510 m in the floods between 2009 and 2019, corresponding to the increase in the curvature coefficient of the river from 1.40 to 1.56. According to the results of RNCI, the flood of 2019 with a discharge of 1167.73 m³ caused the highest amount of erosion compared to the other floods. Among the studied reaches, the most changes in geometrical parameters belonged to reach B
Geomorphology
Mojtaba Yamani; Shahnaz joudaki
Abstract
Terraces are important archives for paleontology. In this research, the paleotemperature changes and discharge frequency of Jajroud basin in the northeast of Tehran have been investigated based on the sedimentology and geochemistry characteristics of the reservoirs. First, the sediment samples were analyzed ...
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Terraces are important archives for paleontology. In this research, the paleotemperature changes and discharge frequency of Jajroud basin in the northeast of Tehran have been investigated based on the sedimentology and geochemistry characteristics of the reservoirs. First, the sediment samples were analyzed with calcimetry, EC, XRF, and PH techniques, and then these data were correlated with the indices of salinity, chemical weathering, acidity, and maturity of the sedimentary layers of the defenses. The results show three periods of flow changes, during the alternation of cold and warm periods of the river. One is at the peak of the glacial period, when the accumulation of snow and ice in the mountainous part has reduced the discharge (before the Holocene). In the second stage, by passing from the glacial period to the warm period (11 to 8 thousand years ago), Jajrud has experienced its highest discharge. Because the melting of glaciers has been accompanied by rainfall. The existence of very coarse layering in the early Holocene terraces indicates the occurrence of floods in this period. In the third stage, the dominance of recent hot and dry conditions (8 thousand years ago until now) and the lack of glacial deposits have led to a decrease in river flow. Based on this, the geochemical studies of the reservoirs can provide valuable data to recover the dynamic changes of flow and discharge during the Quaternary period and can be generalized to other similar basins.
Geomorphology
Raoof Mostafazadeh; Fariba Esfandyari Darabad; Ahmad Naseri; Ahmad Abyat; Maryam Adhami
Abstract
Fractal dimension is a powerful and important index that reflects the physical and morphological characteristics of rivers and has a close relationship with geometric features of rivers. The fractal pattern was used to investigate the sinuosity of the Gharehsou River in Ardabil Province, using the box-counting ...
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Fractal dimension is a powerful and important index that reflects the physical and morphological characteristics of rivers and has a close relationship with geometric features of rivers. The fractal pattern was used to investigate the sinuosity of the Gharehsou River in Ardabil Province, using the box-counting method. The results show that the fractal dimension of the Gharehsou River varies between 2.068 and 2.186. The minimum fractal dimension is in the first category of meanders with lower areas of tangent circle, and the maximum number of circles falls into the eighth category (having high areas of tangent circle). Based on the correlation between the number and area of tangent circles (0.71 to 0.84), it can be said that the river reaches studied follow a fractal and self-similar pattern. The fractal dimension values in the Anzab village-Taleb Qeshlaqi village reach were calculated to be 2.23, indicating a higher level of self-similarity, which is related with the naturalness of this river reach, which is located within a plain area, and the river has undergone more evolution. On the other hand, in the Taleb Qeshlaqi village-Sabalān Dam reach, the fractal dimension value was found to be 1.85, which may be related to the river traversing steeper paths, limiting its meander development and making the fractal pattern less observable. Human interventions in the river's course, as well as the river's passage through agricultural lands in some cases, have led to changes in the width and depth of the river and restrictions on meander expansion.
Geomorphology
Amirhosein Ghorbani; Raoof Mostafazadeh; Mohsen Zabihi; Masoud Jafari Roodsari
Abstract
Landslide, as an important natural hazards, causes damage to infrastructure and leads to economic, social and human losses. In this regard, determining the critical zones of landslides occurrence can be used in planning for damage reduction. The aim of the current research is analyzing and identifying ...
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Landslide, as an important natural hazards, causes damage to infrastructure and leads to economic, social and human losses. In this regard, determining the critical zones of landslides occurrence can be used in planning for damage reduction. The aim of the current research is analyzing and identifying landslide hot spots using Getis-Ord algorithm in Gharnaveh watershed, Golestan province. Therefore, the frequency and characteristics of landslides has been analyzed in different classes of slope, aspect, soil and land uses. The area, length, width, depth and height of the precipice of landslide features have been considered as the basis in hot spot analysis. The results showed that the landslide hot spots are located in the eastern part of the study area, which includes high altitude classes, rangelands and moderate slopes. Results showed that the rangeland and forest land uses, loess soils and 50-75% slope class and the northern aspect had the highest number of landslides. Also, the non-significant landslide points using the Getis-Ord method and considering landslide area criterion located in the middle and downstream of Gharnaveh watershed. Determining the landslide hotspots and affecting factors through the spatial analysis in GIS provides the defining thresholds in the landslide’s occurrence. The analysis of the landslide hotspots can be a basis for spatial planning, and risk reduction. The implemented approach can be used in the evaluation of the spatial autocorrelation of natural hazards, and in combination with the areas prone to multiple environmental hazards can predict the risk and severity of damages in the future.
Geomorphology
mehdi feyzolahpour
Abstract
Glacier cirques show the characteristics of past glaciers and climates. In this research, the analysis of 39 glacial cirques in the catchment area of Jajrud River was done. For this purpose, Arc GIS software and Google Earth images were used. The parameters of length, width, height of the top of the ...
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Glacier cirques show the characteristics of past glaciers and climates. In this research, the analysis of 39 glacial cirques in the catchment area of Jajrud River was done. For this purpose, Arc GIS software and Google Earth images were used. The parameters of length, width, height of the top of the circus, height of the floor of the cirques , area, perimeter, ratio of length to width, ratio of length to height of floor and ratio of width to height of floor were used to check the morphometry of cirques. For each of the morphometric parameters, statistical factors of coefficient of variation, standard deviation, average, maximum and minimum were calculated and estimated in Excel. Then R2 values or coefficient of determination were estimated for each of the parameters and a scatter diagram was drawn. Finally, the correlation matrix was estimated using the Pearson correlation coefficient for all factors. The highest abundance of cirques is located in the southwest direction. The maximum height of the cirques is 3800 meters and belongs to the geographical direction of the south.The highest correlations between length and width parameters were observed at the rate of 0.9936. The results show that the cirques in the north-facing slopes have a lower height. This indicates the high nutrition of these cirques and their significant volume in the Pleistocene period. Investigations showed that more developed cirques have more area, less height and less length to width ratio than less developed cirques .
Geomorphology
somayyeh moazzez; Davoud Mokhtari; Mohammad hossein Rezai Moghadam
Abstract
AbstractAlluvial fans are among the areas prone to geomorphological hazards. One of these hazards is liquefaction, which the main purpose of this research was to investigate this phenomenon in the surface of the alluvial fan. The FUZZY-VIKOR combined model and GIS technique were used to prepare the liquefaction ...
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AbstractAlluvial fans are among the areas prone to geomorphological hazards. One of these hazards is liquefaction, which the main purpose of this research was to investigate this phenomenon in the surface of the alluvial fan. The FUZZY-VIKOR combined model and GIS technique were used to prepare the liquefaction risk potential map. The used parameters in this research were: slope, depth of underground water, type of soil and seismicity. The information layers of each of these parameters were prepared in the ArcGIS software environment. Next, the fuzzy model was used to standardize the layers. At the end, the weighting of the parameters was done by Vikor method. . The results of weighting the parameters by Vikor method showed soil and depth of underground water have obtained the highest importance coefficient with the weight of 0.442 and 0.236 respectively. The final map was prepared by overlapping the layers and multiplying the final weight of the criteria in each layer in 5 classes from very low to very high potential. The final map was prepared by overlapping the layers and multiplying the final weight of the criteria in each layer in 5 classes from very low to very high potential. The results of examining the area of each risk class showed that 0.28% of the area is in the very high class and 70% is in the high class in terms of the risk of liquefaction. Mainly, the areas with high risk potential are located in the downstream parts of the region.
Geomorphology
elnaz piroozi; Aghil Madadi
Abstract
AbstractSoil erosion is one of the most important problems in the watersheds of Iran, which causes the loss of thousands of tons of arable soil every year. The aim of the present study is to zoning the risk of soil erosion in Givi Chay watershed (northwestern Iran). In this study, first, the effective ...
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AbstractSoil erosion is one of the most important problems in the watersheds of Iran, which causes the loss of thousands of tons of arable soil every year. The aim of the present study is to zoning the risk of soil erosion in Givi Chay watershed (northwestern Iran). In this study, first, the effective factors for erosion in the region were identified and then the information layers of each criterion were prepared in Geographic Information System (GIS). Valuation and standardization of layers was done using fuzzy membership function and criteria weighting, using critic method. Final analysis and modeling was performed using the Multi-Attributive Border Approximation Area Comparison (MABAC) method as one of the Multi-Criteria Decision Making (MCDM) methods. According to the results of the study, slope, land use, soil and lithology had the highest weight coefficient, respectively. Also, the results of the study showed; 283.89 and 414.93 km-square of the area, respectively, has a very high and high risk potential, and very high-risk and high-risk areas in unstable and erodible formations, agricultural uses and gardens and slopes of 25-40 % are located. It can be said that the results of this study indicate the high potential of the study basin in terms of erosion occurrence and it is necessary to control erosion and conservation measures on the agenda of experts and land managers. In addition, the results of validation of the results showed that the use of MABAC method has a high relative accuracy for studying the risk of erosion.
Geomorphology
leila aghayary; Mousa Abedini
Abstract
Therefore, the purpose of this research is to investigate and analyze the most important factors involved in creating the risk of subsidence in the Ardabil plain and to identify the susceptible surfaces that are likely to be involved in subsidence in the near future. The purpose of this research in the ...
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Therefore, the purpose of this research is to investigate and analyze the most important factors involved in creating the risk of subsidence in the Ardabil plain and to identify the susceptible surfaces that are likely to be involved in subsidence in the near future. The purpose of this research in the first stage is to evaluate the subsidence using radar interferometry technique in the Sarscape software environment, using the capabilities of A1 Sentinel images in the time frame of 2016 and 2021, and also in the following, in relation to the zoning of susceptible areas with the algorithm Aras multi-criteria was implemented in Edrisi software environment. The results of the present study showed that between 0 and 22 mm of subsidence has occurred in the studied area, and the highest amount of subsidence is concentrated in the central part and then in the eastern and north-eastern parts. According to the results of subsidence risk zoning; The criteria of water level drop, distance from the river, geology, and land use are the most important factors involved in creating the risk of subsidence in the study area, respectively, with a weighting factor of 0.221, 0.166, 0.152, and 0.147, respectively, and 267/41 and 403/21 square kilometers of the range have a very high probability of danger. Finally, it can be said that the most important factor involved in increasing the amount and potential of subsidence in the Ardabil plain is the excessive use of underground water and the drop in the water level.
