Geomorphology
leila aghayary; sayyad Asghari Saraskanrood; Batool Zeynali
Abstract
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. ...
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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.
Hydrogeomorphology
Aghil Madadi; sayyad Asghari Saraskanrood; Hossein Hajatpourghaleroodkhany
Abstract
the purpose of this research is to reveal the changes in land use and the destruction of forest cover and its effects on soil erosion in the watershed of Ghaleroodkhan Fuman.In the next step, using the object-oriented classification method and the nearest neighbor algorithm by eCognition software, land ...
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the purpose of this research is to reveal the changes in land use and the destruction of forest cover and its effects on soil erosion in the watershed of Ghaleroodkhan Fuman.In the next step, using the object-oriented classification method and the nearest neighbor algorithm by eCognition software, land use maps were extracted in 1992 and 2023. In the next step, by identifying the effective factors involved in the erosion of the area and preparing the information layers of each criterion in GIS, the valuation and standardization of the layers were done using the fuzzy membership function and the weighting of the criteria, using the CRITIC method. Eventually; The final analysis was done using the MARCOS method. The forest cover of the studied area has experienced a decrease of about 1700 hectares in its area. Also, residential use with an increase of 27.17 square kilometers has changed the most during the 30-year period of study. In addition, the most important land use change in the basin has been the destruction of forests and their conversion to agricultural lands, pastures and settlements, as well as the conversion of agricultural lands to residential areas, and this method of land use change and conversion, along with other natural factors in the area, Such as; The distribution of loose and erodible formations, high slope, adequate rainfall and the abundance of river have played the greatest role in increasing the soil erosion potential of the Ghaleroodkhan basin.
Groundwater
sayyad Asghari Saraskanrood; Maryam Riahinia
Abstract
Today, due to population increase, industrial development, excessive exploitation, droughts, exploitation of underground water has multiplied. Therefore, identifying areas with underground water as one of the important sources for providing drinking water, agriculture, and various industries is considered ...
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Today, due to population increase, industrial development, excessive exploitation, droughts, exploitation of underground water has multiplied. Therefore, identifying areas with underground water as one of the important sources for providing drinking water, agriculture, and various industries is considered to be one of the important and necessary issues in water resources management. The purpose of this research is to investigate and zonate the areas with underground water in Khorram Abad plain located in Lorestan province using convolutional neural network method. For this purpose, maps of nine factors affecting underground water were first prepared in the ArcGist environment. In the convolution method, the number of samples was determined as the ratio between the training set and the test set was 70:30, and the convolution neural network framework was used as 2 convolution layers and 2 integration layers, 2 complete connections. layers and finally the sigmoid layer was used for classification from the 3-3 convolution kernel, the Relu function as the activation function and the cross entropy function as the loss function. The obtained maps were classified into 5 classes: very good, good, average, low and very low. Confusion matrix was also used to validate the results of the model. 30% of the real data was used for evaluation, which resulted in an overall accuracy of 92%, that is, the model was able to correctly identify 92% of the data as underground water and 93% as the absence of underground water. The analysis of the groundwater potential map of the convolutional neural network model shows that about 57% of the area is in low groundwater conditions and 43% of the area is in good groundwater conditions.
Hydrogeomorphology
hasan Setayeshi Nasaz; sayyad Asghari Saraskanrood; Raoof Mostafazadeh; Aghil Madadi
Abstract
Rivers are very important in terms of human uses and ecological functions. In the present research, the environmental flow components of the Khiavchai River have been determined. Therefore, changes in the EFCs were determined using IHA software. According to the results, the values of low flows were ...
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Rivers are very important in terms of human uses and ecological functions. In the present research, the environmental flow components of the Khiavchai River have been determined. Therefore, changes in the EFCs were determined using IHA software. According to the results, the values of low flows were high in the first period (1988 to 2017), but decreased in recent periods. Also, the decrease in the discharge values of the maximum flow indicators and the increase in the number of days with zero discharge to the number of 174 days were also caused by the change of the river regime. The amount of peak rate and decline rate components has increased in recent periods. The values of low flow duration indicators and low flow frequency have increased. Based on the change of flow dispersion index, the occurrence of strong or very low flows in the river has been intensified. According to the FDCs, in the early periods of the river flow regime, river flow was higher than 0.01cms during the year, while in recent periods it has decreased to less than 0.001cms. Based on the changes in the duration of the flow in recent periods, the duration of the river has changed to 50-60% of the days of the year with a very low discharge. Overuse of river flow changes in the flow regime, and successive droughts have increased the severity of the change in the flow regime and the deviation of the river conditions from the normal state.
Geomorphology
sayyad Asghari Saraskanrood; abozar sadeghi; elham molanouro
Abstract
Snow-covered (SC) surfaces influence the land surface energy balance through albedo feedback, and also have a major impact on climate processes, human activities, and the hydrological cycle. Land surface temperature is one of the main elements in knowing the climate of a region, whose changes and fluctuations ...
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Snow-covered (SC) surfaces influence the land surface energy balance through albedo feedback, and also have a major impact on climate processes, human activities, and the hydrological cycle. Land surface temperature is one of the main elements in knowing the climate of a region, whose changes and fluctuations in different altitude classes are very useful for hydrological studies. The purpose of this study is to evaluate and investigate the relationship between ground surface temperature and snow cover level with the topographical component of height in Urmia lake basin. In this research, due to the ease of access to remote sensing data and the appropriate temporal and spatial separation of Terra satellite images, monthly, seasonal and annual MODIS sensor images have been used in the period of 1379-1399. The obtained results show that there is an inverse relationship between LST and SC, also the examination of SC maps and elevation classes shows that there is a direct relationship between these two variables, in fact, with the increase in altitude, the stability of snow in the region increases so that at altitudes higher than 3000 m, the amount of snow cover is more than 98% compared to the region. The changes in the temperature of the earth's surface at different altitudes are the reverse of the changes in the snow cover, so at altitudes less than 2000 meters, the annual average temperature is 21-35 Celsius, but at altitudes higher than 3500 meters, the average temperature is about 7-13 Degree.
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.
Aghil Madadi; Zohreh Bashokoh; Ehsan Ghale
Abstract
1-IntroductionOne of the most important wealth of a nation is the water that is flowing in the rivers of that country, and because of its impact on the settlement, site selection and development of villages, cities, communication networks and agriculture, it is of great importance since the past. Because ...
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1-IntroductionOne of the most important wealth of a nation is the water that is flowing in the rivers of that country, and because of its impact on the settlement, site selection and development of villages, cities, communication networks and agriculture, it is of great importance since the past. Because of this, human attention has been given to river systems as one of the most vital constituents of the earth's surface in a variety of respects. River morphology is a multifaceted branch of earth science that may be considered as a specific geomorphological subject. One of the most important purposes of investigating river morphology is the geometric description of river bed parameters and interpretation of its main causes with the help of the theoretical knowledge base of water flow, solids and sediment transport. Changes in river morphology can cause many problems, including river diversion, flooding of surrounding areas, damage to hydraulic structures, as well as some environmental impacts. Short-term river variability may be gradual and continuous, but the long-term variability or under certain conditions, it is inconsistent and abrupt. One of the factors that can severely impair the stability of rivers is the construction of dams. Flow changes by the dam can affect the amount, timing, and duration of upstream and downstream currents. The purpose of this study was to investigate the morphological changes (patterns and dynamics) of the Gharasu River (from Samian Bridge to Sabalan Dam) over a period of 19-years (2000–2019). 2-MethodologyThe study area of the Gharasu River is approximately 51 km 2 in geographical coordinates of 48 ° 2 min to 48 ° 18 min east longitude and 38 ° 22 min to 38 ° 30 min north latitude in the political-administrative boundary of the city of Ardabil. The highlands of the region are mainly composed of Eocene volcanic rocks. There are also two Quaternary units of Qsc and Qst related to Sabalan volcanic activity. The study area is located in the geological division of Iran in the Alborz-Azerbaijan zone. In most of Iran's construction divisions, the Azerbaijan region has been considered the continuation of central Iran. Topographic maps, geological maps, Landsat, Sentinel and Google Earth satellite imagery, digital elevation model (DEM) images, and climatic and hydrometric data were used in the study. In order to quantify the meandering development of alluvial rivers and determine the behavioral pattern and its changes over time, the geometrical characteristics of rivers such as central angle, meander radius, wavelength, valley length and bending coefficient ( Sinusitis), were measured and analyzed to determine changes in the course of the river channel from the past up to the present. 3-Results and DiscussionThe mean radius of meanders for the entire Gharasu River channel during the study periods of 2000, 2010, and 2019 were 11.02, 100.90, and 99.40 meters; respectively, indicating a decreasing trend. The average length of arches during these years was 254.29, 250.24 and 251.74 meters; respectively. For this reason, over the years under the study, the mean central angle has an increasing trend from 138/50 in 2000 to 153/15 in 2010 and 157/41 in 2019. The mean curvature coefficients for the entire study period from the Gharasu River for the periods 2000, 2010 and 2019 were 1.58, 1.61 and 1.63;respectively. The values of this index during the years 2000, 2010 and 2019 were about 2.40, 2.52 and 2.58; respectively, which is of a severe meander type. The average rate of migration (Rm) of the study period from the Gharasu River during the years 2000 to 2010 was about 0.5 m / year. The value of this indicator for the period 2010 to 2019 has decreased to about 0.3 meters per year. According to calculations, the index has grown to about 0.4 m / year over the past 19 years (from 2000 to 2019). Another method called transect method was used to evaluate lateral variations of the study through the Gharasu River channel. According to calculations using the transect method over the past 19 years, a total of approximately 22.45 hectares of the Gharasu River margin lands have been lost due to erosion processes during the study period. This amount was about 13.75 ha during the period 2000 to 2010 and about 10.22 ha during the period 2010 to 2019.4-ConclusionIn this study, the morphology and lateral variations of the ditch of Gharasu River in Ardabil province were evaluated. Based on geomorphological conditions, slope and width of the flood plain as well as other factors (such as river discharge variations), the river was divided into three sub-intervals and 30 transects in the study area. In addition to the visual interpretation, in order to evaluate and analyse the morphology of the Gharasu River, quantitative indicators were required. The present study used four indices of curvature, central angle of the cornice, channel migration rate and transect method to detect and identify the river pattern as well as lateral channel changes. These indices were calculated over the time periods of 2000- 2010, and 2010-2019 for the study river channel. The results showed that the Gharasu River has had a developed meander pattern in most of the studies. The results of the two channel migration rate indices and the transect method also confirmed that, overall, the transverse changes of the Gharasu River channel have been low. Also, these two indices, similar to the Cornis curve coefficient and the central angle, showed that transverse dynamics have declined sharply in the last decade.
Sayyad Asghari; Rasool Hasan zadeh; Soheil Raoofi
Abstract
1-Introduction Instability of natural slopes is one of the geological and morphological phenomena that has a significant role in changing the form of surface of the earth, and when it affects human activities, it can become a dangerous phenomenon (Esfandiari, 2006: 113). Landslides as geological events ...
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1-Introduction Instability of natural slopes is one of the geological and morphological phenomena that has a significant role in changing the form of surface of the earth, and when it affects human activities, it can become a dangerous phenomenon (Esfandiari, 2006: 113). Landslides as geological events related to the transportation of soil / heavy rock materials and assessment of its sensitivity, is an important task for local authorities to plan and reduce the land (Xialong Deng, 2017: 2). Therefore, many attempts have been made to assess the dangers of mass movements, and it is suggested to have its reduction methods based on the key characteristics of the slip, including scope and extent, volume, startup mechanism and recurrence, and subsequently, make decisions (Kuo Jeong Chank et al., 2018: 700). (Hemati and Hejazi 2017: 24-7) evaluated the landslide hazard zonation of Lavasanat watershed using logistic regression statistical methods and the result was stated in this way that in the studied area, areas with high risk of zoning, had a large share of the area amount of the region. Aliabad basin with the southwest - northeast trend in the geographical coordinates of - located in the east and - located in the north latitudes of the northeast of East Azarbaijan Province and southeastern part of Horand County.(Figure1) Figure (1): Geographic location of Aliabad watershed 2-Methodology 1- Topographic map (1: 50000) and geological map of Kaleybar region (1: 100000). 2- Landsat satellite images of 8 OLI sensors 3- GPS devices 4- Maps of the faults, slopes, isohyet, isotherm, evaporation, land use, elevation and hydrology 5- Envi 5.3 software 6- Statistical software of SPSS, version 16. For zoning the risk of rock falls, nine layers of information including slope, hypsometry of the region, isohyet, isotherm, evaporation, distance from the fault, distance from the river, land use and lithology were used as independent variables and to prepare the layers in Arc GIS, 1,500,000 topographies and 1.100000 geology maps were utilized, and Landsat 8 satellite imageries were used with the OLI sensor to produce the land use layer. So, after preparing the considered data, the layers were classified as raster, and in their descriptive table, a column called the standard weight was added and the classes related to each layer were calculated using a sum ranking method. In this research, the rock fall layer was considered as the dependent variable and the 9 presented layers were considered as independent variables and all layers had been evaluated in the normalization of the weight between zero and one per pixel; based on the proportion table method, each layer, having 500 weighted pixels that overall included 5000 pixels, was entered into the SPSS environment and regression analysis was performed thereof. Independent variables, including 9 variables, consisting of three PhDs in geomorphology and two Phd in geology were selected based on exports opinions considering their importance in creating and strengthening the dependent variable were weighted between zero and one numbers. 3-Results and Discussion The Chi square test for each of the independent variables, separately, showed that there was a significant relationship between the independent variables and the dependent variable, and the effects of these variables on the dependent variable was acceptable. The numerical value of R was 0.953, and if the R value was closer to one, it would indicate the high validity of the test. The numerical value of the coefficient of determination of the independent variables relative to the dependent variable was 0.909, which indicated the high validity of the significance of the test, because it was closer to number one. Of course, it is clear that the value of the determination coefficient in Pseudo R Square was determined to be good, so the adjusted coefficient of determination was considered whose numerical value was 0.907. These findings indicated that roughly 90 percent of rock falls occurred in the Aliabad basin have been affected by these 9 estimated independent variables. Given that the statistical analyzes confirmed the validity of the effects of independent variables on the dependent variable according to the weightings of the experts in terms of zero and one for each variable as well as the importance of the variables in relation to each other as a binary comparison, the zoning of the risk of rock fall for the Aliabad watershed of the Horand basin was done using Arc Gis software, and in this zonation, five falling risk classes were used including very high, high, medium, low and very low . 4- Conclusion lithology and the distance from the fault and river and foot slopes were the most important factors in the formation of rock falls since the drainage system of the basin exactly followed the fault zone. The reason for this issue can be analyzed in the way that the longitudinal distance of the highest parts of this region, from the basin to the Aliabad River was lower, which has caused the slope of the basin to perform deep slices to achieve a balance in the slopes and hydrology. The southern parts of the basin are considered as one of the most susceptible basins in the geomorphologic phenomenon of rock falls and destructive cones due to the existence of alluvial formations and the lack of proper slopes and the relative reduction of the fault to the northern and eastern parts despite having significant heights and very low and low status of zonation in the risk of rock falls, and in the southwestern part of the basin, a presence of rocky outcrops in the presence of permeable cones has been also observed. This issue should be addressed to the authorities in order to avoid serious damages to the lives of the inhabitants of the basin, so that the potential risks of this phenomenon could be controlled as much as possible including: threatening communication routes and threatening rural villages and damaging electrical and telecommunication facilities, therefore, infrastructure solutions should be applied in this regard.
Sayyad Asghari Sarskanroon; Batool Zeinali; Nader Poornariman
Volume 2, Issue 3 , January 2017, , Pages 1-20
Abstract
Rivers are dynamic systems that lateral boundaries and their morphologic characteristics are changing in time continuously. This instability is created by erodibility of river bed and consequently river patterns changing. Case study of this research is Germi Chay in East Azerbaijan province. ...
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Rivers are dynamic systems that lateral boundaries and their morphologic characteristics are changing in time continuously. This instability is created by erodibility of river bed and consequently river patterns changing. Case study of this research is Germi Chay in East Azerbaijan province. The purposes of this study are investigation of river patterns and determining erodibility of river route. For these used Landsat satellite images, digital elevation model (DEM), vegetation, geologic and land use maps. In order to determining of river pattern and its Effective factors were used Sinuosity, Central angle indexes and longitudinal profile analysis. Finally river erodibility classes were determined in 5 classes by overlaying effective layers in erodibility. Results indicated pattern of studied river is meandering. Longitudinal profile analysis in both intervals indicated that changing of situation is not seen in longitudinal profile and these changes are in a normal state. This is indicator regular trend in effective factors of river morphological actions. Also results indicated that erodible areas of Medium to high and high are in parts with Structures sensitive to erosion (mainly Quaternary sediments), the lack of suitable and dense vegetation that are caused slope movements in river bed.
Sayyad Asghari Sarskanrood; Mahdi Poorahmed
Volume 2, Issue 5 , January 2017, , Pages 1-16
Abstract
Variations in route and morphology of the rivers are among the important characteristics of floodplains. Since these variations occur within time scale, it is appropriate to study those using remote sensing techniques. This study aims to identify and extract part of Zarineh Rud river variation from 1989 ...
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Variations in route and morphology of the rivers are among the important characteristics of floodplains. Since these variations occur within time scale, it is appropriate to study those using remote sensing techniques. This study aims to identify and extract part of Zarineh Rud river variation from 1989 to 2014 using landsat satellite images. To gain this objective, radiometric and geometric modifications have been carried out in the first phase. Afterward, the images have been developed by linear method for enhancing the resolution. Then, by principal component analysis and band combination, the best component and band were determined. By adding these components and bands to ArcGIS, the river range within the mentioned time span was extracted and analyzed. Furthermore, for quantitative analysis of the river route variation, curvature coefficient and Fereaktaly dimension indices were used to compare the different years. It was found that there is a low potential in river to have morphologic variations in different parts. This is due to the fact that there has been a negligible change in river flow rate since 2000. The highest variation is observed in 1989. Instability of the river route during the studied time span was very low, except for one of the river’s twists from the 1989 pattern. The results of river extraction methods also confirmed that principal component analysis for identifying the border line of the river is more appropriate than the other methods.
Sayyad Asghari; Batool Zeinali; Saleh Asghari
Volume 3, Issue 7 , October 2016, , Pages 39-57
Abstract
Sayyad Asghari[1]* Batool Zeinali[2] Saleh Asghari[3] Abstract The location of human settlements and other facilities created by human are affected by Environmental factors, particularly geomorphology and geology. Today, as a result of population growth, development of construction is inevitable and ...
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Sayyad Asghari[1]* Batool Zeinali[2] Saleh Asghari[3] Abstract The location of human settlements and other facilities created by human are affected by Environmental factors, particularly geomorphology and geology. Today, as a result of population growth, development of construction is inevitable and the adverse impact of human needs on the ground as well as operation of areas around city and villages for creating of home and economic and industrial facilities have increasing expansion. Meanwhile, a plurality of geomorphological factors and dynamics of the natural environment makes difficult possibility of assessment all factors in order to recognize the best location for the placement elements of development. So the use of efficient methods of evaluation will be the most important measures for better planning. Accordingly, the aim of present study is using from Topsis method to locate the best places of natural and geomorphologic structure for future development of Urmia. In this study with entering of area data layers to the ARC GIS and based on topographic factors, the most important constraint of morphological Urmia, was diagnosed three sites suitable for development that proposed sites using natural and morphological components and by techniques Fuzzy ANTROPY (for index weighting) and TOPSIS (to prioritize sites) were evaluated. According to research, site C in the eastern part of the city by a factor of 0.76877 CI as the best place in Urmia is intended for future development. [1]- Assistant of Geomorphology, Urmia University, (Corresponding Autor), Email:s.asghari@urmia.ac.ir. [2]- Assistant of Climatology, University of Mohaghegh Ardabili.. [3]- Ph.D Student of Geography and Rural Planning, Kharazmi University.
