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
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.
Reza Aghayari Samian; Ali Mohammad Khorshid Doust; Saeed Jahanbakhsh Asl; Aida Hosseini Baghanam
Abstract
The aim of this study was to predict changes in temperature, precipitation and evaluate the effects of climate change on the status of surface runoff in the Aras catchment. Climatic conditions were simulated in LARS-WG software environment under RCP8.5 scenario. Using the modified Trent White experimental ...
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The aim of this study was to predict changes in temperature, precipitation and evaluate the effects of climate change on the status of surface runoff in the Aras catchment. Climatic conditions were simulated in LARS-WG software environment under RCP8.5 scenario. Using the modified Trent White experimental model, the amount of potential evapotranspiration was estimated for both observation and simulation periods. To ensure the validity of the model, the mean error orthography (RMSE), and the determination coefficient and Nash-Sutcliffe efficiency coefficient (ENS) were used. Also, modeling of surface runoff changes in GIS software environment and SWAT plugin was performed. After forming hydrological units (HRU), the baseline model for surface runoff changes was selected to calibrate and validate the model. The results show that by modeling climatic data during the simulation period, the amount of temperature, evapotranspiration and transpiration will increase, and in contrast, the amount of precipitation has occurred and the flow rate will decrease superficially. The results of validation showed that the accuracy of the model in the selected stations was high and for the precipitation parameter due to its discontinuous nature, the correlation between the data is less than the temperature parameter and different. The results of hydrometric modeling of the basins showed that the Nash-Sutcliffe value is close to 1 and the correlation coefficient between the data is 0.99, which indicates the high efficiency of the model for simulating and estimating climate change and its effects on surface runoff.
Geomorphology
Ali Bigham; S.Asedolah Hejazi; Mohammad Hossein Rezaei Moghaddam; Jamshid Yarahmadi; Fariba Karami
Abstract
Changes in erosion and sedimentation of the basin are one of the most important factors that affect different parts of human life and natural life. it is very necessary to receive these changes quantitatively, which mainly take place under temperature fluctuations and climate changes in different regions, ...
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Changes in erosion and sedimentation of the basin are one of the most important factors that affect different parts of human life and natural life. it is very necessary to receive these changes quantitatively, which mainly take place under temperature fluctuations and climate changes in different regions, in order to be more prepared to deal with its negative consequences. In this research, erosion and sedimentation changes in Hajiler watershed were investigated and predicted using GeoWEPP and SWAT models. Based on this, first, by using the data of the current situation of the Ahar synoptic station and using the SDSM model, the changes of the statistical period2020-2040 in three scenarios RCP2.6-RCP4.5-RCP8.5 were investigated, then simulation and prediction of erosion changes was carried out. and sedimentation was done under the influence of climate change by using popular models. The output of the SDSM model indicates an increase in temperature and a decrease in rainfall for the basin until 2040.And the analysis of the simulation results of the sedimentation rate of the models showed that in the studied basin, the GeoWEPP with the selection of the domain method has a suitable level in estimating the sedimentation rate compared to observational statistics. The final model was chosen to predict the amount of sediment in the mentioned period of the basin. Using the downscaled results of the atmospheric general circulation model, the sediment changes in the statistical period of 2020-2040 under the above mentioned three scenarios were estimated as -1.97, 4.45, and 2.98, respectively.
Sayyad Asghari Saraskanrood; Mostafa Omidifar; Ehsan Ghale
Abstract
Identification of landforms and the way of their distribution is one of the basic needs in applied geomorphology and other environmental sciences and landform maps show the shapes of the earth's surface. This project aims to identify the landforms of the Qaranqu catchment area using object-oriented classification ...
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Identification of landforms and the way of their distribution is one of the basic needs in applied geomorphology and other environmental sciences and landform maps show the shapes of the earth's surface. This project aims to identify the landforms of the Qaranqu catchment area using object-oriented classification methods including nearest neighbor algorithm and thresholding. Landsat satellite imagery for 1990 (TM) and 2020 (OLI) was used for this purpose. First, to apply the classification, atmospheric and radiometric corrections were applied to the images, then to better identify and extract the phenomena, principal component analysis (PCA), and MNF algorithms were used to classify satellite images using classification methods. Object-oriented, which included the nearest neighbor method and thresholding was used. For the accuracy of the maps produced using the two methods of Kappa index and the overall accuracy of the use, the results revealed that the nearest neighbor method is more accurate than the thresholding method. The classification results showed that the highest rate of decreasing changes during 1990-2020 is related to dense rangeland because it has decreased by 12.49 percent and the highest rate of incremental changes is related to irrigate agriculture which is 10.83 percent. The most important reason for this increase is the construction of Sahand Dam over time. In the absence of well-organized planning and the adoption of appropriate policies, the destruction of rangeland will continue and turning it into arable land, which leads to irreparable environmental and economic losses in the region.
Geomorphology
Reza Abbasian valandar; shahram roostaei; Davoud Mokhtari
Abstract
The Tamtaman area is located between 37◦38/00//-37◦44/00//north and 44◦40/30//-44◦59/30// east in northwestern Iran, approximately 15 km northwest of Urmia. This study aims to identify and zoning the potential development of karst in the area of Tamtaman cave in west Azerbaijan province using ...
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The Tamtaman area is located between 37◦38/00//-37◦44/00//north and 44◦40/30//-44◦59/30// east in northwestern Iran, approximately 15 km northwest of Urmia. This study aims to identify and zoning the potential development of karst in the area of Tamtaman cave in west Azerbaijan province using the AHP method. In this study, the information layers of lithology, tectonics, topography, slope, aspect, hydrology, land use, and climate have been considered as factor maps. The above layers have been called to extract the karst potential model in the GIS environment. Different information layers were classified as Criterion maps by applying expert judgment and assigning the weight of each layer in Expert Choice software and field visits. Finally, according to the obtained weight, the karst development zoning map in the Tamtaman area was obtained. The results obtained in this region exhibited a total area, of 6.68% within the very poorly developed class, 15.64% in the less developed class, 42.50% in the normal developed class, and 35.18% in the developed floor are located. The results show that in the Tamtaman region, the lithological and tectonic factors have the highest weight and are the most important factors controlling potential karst growth, while the land-use factor has the least impact on karst formation.
Hydrogeomorphology
Fatemeh Novin Sarandi; Ghodrat Barzeghari; Mahdi Ojaghi; Nasir Nouri
Abstract
Hajilar chai basin located in the western part of varzegan and it may expose to potential of water resources contamination due to placement of Zarrin Dagh Astarkan gold extraction factory in this area. In order to monitor the water sources of the Hajilar chai basin, 12 water samples collected and analyzed ...
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Hajilar chai basin located in the western part of varzegan and it may expose to potential of water resources contamination due to placement of Zarrin Dagh Astarkan gold extraction factory in this area. In order to monitor the water sources of the Hajilar chai basin, 12 water samples collected and analyzed in March 2021. The results showed that the concentration of Co, Pb and As are higher than permissible limit of WHO standard for drinking water in some places and probably the source of trace element related to geological formations and water rock interaction. The aim of this study is to evaluate the hydrchemical characteristics and source of contamination of water sources using graphical methods, multivariate statistical techniques such as factor analysis and hierarchical cluster analysis. The result of the graphical methods showed that the most of the water samples have bicarbonate calcium dominate type. The result of the factor analysis show that four factors were affecting the quality of water source. The first, third and fourth components result from affecting of formation on water resources and water rock interaction. The second component show evidences of the anthropogenic activities in the study area. Also, hierarchical cluster analysis classifies the data into three categories. The first cluster data have similar geochemical process and less trace element. In second cluster hydrochemcial equilibrium is not established, which is probably due to the impact of factory activities. In third cluster, the concentration of arsenic is high and probably is originated from geological formation.
Mohammad Hossein Rezaei Moghaddam; Davoud Mokhtari; Majid Shafieimehr
Abstract
Floods are one of the most common natural hazards, causing significant loss of life and property each year. The purpose of this study is to determine the risk areas of floods in Shahr Chai Miyaneh watershed. To implement this model, different layers such as slope, aspect, elevation, distance from river, ...
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Floods are one of the most common natural hazards, causing significant loss of life and property each year. The purpose of this study is to determine the risk areas of floods in Shahr Chai Miyaneh watershed. To implement this model, different layers such as slope, aspect, elevation, distance from river, river density, land use, vegetation, lithology, rainfall and soil were used. The final analysis and modeling was performed using the Vikor model. The results showed that rainfall, slope and distance from the river have the greatest impact on the occurrence of floods in this watershed. Also, according to the obtained results, 5.2 and 1021.7 square kilometers, respectively, are located in a very high-risk and high-risk area. Dangerous and very dangerous areas are mainly located along the main river and mountainous in the steep logic. Due to the high slope and height of the region, it plays an effective role in the amount of runoff and flow peak floods. Also, in the catchment area of Miyaneh Chai city, 2.2, 27.2, 1099.6, 1021.7 and 10.2 square kilometers, respectively, are in a very low risk, low risk, medium, high risk and very high risk area.
Davoud Mokhtari; Mohammad Hossein Rezaei Moghaddam; Somayyeh Moazzez
Abstract
1-IntroductionDebris flows are mass movements that always threaten human activities and cause a lot of damage. The aim of this study was to zoning the risk of debris flow in the Leilan Chai catchment located in East Azerbaijan province and the impact of this hazard on the Leylan alluvial fan. For this ...
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1-IntroductionDebris flows are mass movements that always threaten human activities and cause a lot of damage. The aim of this study was to zoning the risk of debris flow in the Leilan Chai catchment located in East Azerbaijan province and the impact of this hazard on the Leylan alluvial fan. For this purpose, 10 effective criteria in the occurrence of this hazard, including slope, aspect, elevation classes, land use, lithology, precipitation, distance to fault, river density, distance to river and distance to road were used to prepare a zoning map for debris flow hazard. Identifying areas with high risk sensitivity helps regional managers and planners to manage and control this risk in the basin.2-MethodologyLeilan Chai catchment as one of the tributaries of Zarrineh Rood River is one of the important rivers in the eastern part of Lake Urmia (Movahed danesh, 1999:45). This basin is located in East Azerbaijan province in terms of political divisions. The area of this basin is 723 Km2 and is located in the geographical coordinates of 37° 00′ 31″ to 37° 38′ 20″ north latitude and 46° 14′ 26″ to 46° 38′ 37″ east longitude. The minimum elevation of the basin is 1356 meters and the maximum elevation in the heights of Sahand Mountain is 3554 meters. This basin forms an alluvial fan at the exit of the mountain that called Leilan. In the present study, the SAW decision-making method has been used to weight the criteria. Layer fuzzy was also performed due to their importance in the occurrence of debris flow in ArcGIS and Idrisi software.3-Results and DiscussionMass movements such as debris flows have always been a threat to the development of human activities. The results of weighting the criteria using SAW method showed that lithology, slope and precipitation criteria with a weight of 0.260, 0.211 and 0.190, respectively, are of more importance in the occurrence of this hazard in the study area. After determining the weight of the criteria and sub-criteria, the layers were overlapped in the GIS environment and a potential map of the risk of debris flow in 5 classes was prepared. The results of the final map show that upstream of the basin area due to having high altitude and receiving more rainfall during the year and also having a high slope are highly sensitive to the occurrence of debris flow. The downstream areas of the basin, despite the high density of river and the presence of numerous faults, but due to the very low slope, show low sensitivity to the occurrence of debris flow.4-ConclusionIn this study, an attempt was made to prepare a map of the risk of debris flow occurrence in the Leilan Chai basin using effective criteria in the occurrence of this risk. The final debris flow hazard map was prepared by overlaying and multiplying the final weight of the criteria in fuzzy layers in GIS environment. The results showed that about 117 Km2 (16% of the area) of the study area is in the high and very high risk classes in terms of sensitivity to debris flow. In contrast, 49% of the total area is low and very low sensitivity to this risk. Areas located in high and very high classes mainly include the upper parts of the basin, which have the potential for this risk in terms of slope, precipitation (more than 400 mm) and lithology (presence of volcanic ash). Also, according to the research results, it can be said that this hazard cannot have much effect on the Leilan alluvial fan. Due to the occurrence of this hazard in the upper parts of the basin, the possibility of transferring these materials to the downstream areas and even the surface of the alluvial fan is very low due to the very long distance.
