Geomorphology
Mohammad Hossein Rezaei Moghaddam; Masoumeh Rajabi; Masumeh Mousavi
Abstract
r optimal land use, it is necessary to be aware of land use changes and the type of land use; this is possible by assessing and predicting land use changes. The purpose of this study is to investigate the trend of land use change over a period of 18 years (2000-2000) and predict it using the Markov chain ...
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r optimal land use, it is necessary to be aware of land use changes and the type of land use; this is possible by assessing and predicting land use changes. The purpose of this study is to investigate the trend of land use change over a period of 18 years (2000-2000) and predict it using the Markov chain model for 2025, 2050 in the Yellow River Basin of Baghmalek city in Khuzestan province. To achieve this goal, first corrections (geometric, radiometric and atmospheric) and necessary processing were performed on Landsat satellite images of 2000, 2006, 2012, 2018; Then, land use maps for four time periods were classified into five classes: green space and gardens, barren lands, agricultural lands, water levels (sedgereh) and man-made residential areas. These changes were addressed using the Markov chain model for 2025, 2050. After making the necessary corrections on the Landsat images, the land use estimate showed that the highest percentage of the study area is barren lands and arable lands. The overall accuracy and kappa coefficient for 2000, 2006 and 2018 are above 0.80 and 0.92. .. The results of revealing the changes between the period 2000 to 2018 showed that barren lands with a rate of 823.51, green space and gardens with a decrease of 157.85 hectares. In contrast to the built-up areas of 439.59 hectares, 1356.56 hectares of arable lands and 404.94 hectares of water levels have been facing an increasing trend. Also, the results of the forecast using the CA-Markov model of land changes in the region for 2025 and 2050 showed that if the speed of land use change is the same as in previous years, in 2025 the use of built-up areas will be 1089.54, hectares of arable land. To 1154/52 hectares and surface water use will increase to 666/54; Landscaping and orchards will be reduced to 42/2012, barren land land use to 59,85279 hectares and in 2050 landscaping and orchards land use to be reduced to 192.62 hectares, barren land land use to be reduced to 8438.69 hectares, arable land land use Increase to 1243.73 hectares and surface water use increase to 8959.59 hectares of built-up areas to 1671/98 hectares. By examining land use change, valuable information can be obtained about man-made changes and natural factors. On the other hand, the prediction map derived from the Markov chain model is very important to provide an overview for better management of natural resources.
Geotourism
asadollah hejazi; Mohammad Hossein Rezaei Moghaddam; zahra ghasemizadgonbad
Abstract
Introduction Ecotourism is one of the common types of tourism activities that has attracted a lot of attention in recent years. The ecotourism concept is based on the ideals of environmental protection and sustainable development and refers to a responsible journey to nature with an emphasis on ...
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Introduction Ecotourism is one of the common types of tourism activities that has attracted a lot of attention in recent years. The ecotourism concept is based on the ideals of environmental protection and sustainable development and refers to a responsible journey to nature with an emphasis on ensuring the improvement of local community life and environmental protection (Seifi and Janbaz, 2017: 479). Ecotourism has a deep connection with sustainable development, which stems from the interactions between tourists and the environment. Proper planning and management in order to develop ecotourism are essential to preserve and maintain the environmental richness of the region as well as the economic improvement of local people (Bunruamkaew and Murayama, 2011: 269). Iran is one of the countries that have a lot of potential for ecotourism development, however, studies show that Iran's natural tourism assets are vast array of scattered, unstabilized resources, and in some cases are on the verge of extinction. The main object of the current paper is to assess the ecotourism potentials and capabilities of the Margavar rural district of Urmia County in northwest of Iran. For this purpose, Analytic Network Process (ANP) and Fuzzy method have been used and ecotourism capabilities zoning map of the study area has been produced. Data and Method The current research is a Multicriteria-based study and the Analytic network process (ANP) method and Geographical Information System (GIS) has been used to analyse the data. Spatial criteria were clustered based on reviewing the background into five main groups including climate, human, topography, geology, and tourism and criteria have divided into these 5 groups. At first, the criteria map was prepared in the ArcGIS environment, then all the maps were reclassified with the Reclassify function. In the next step, the criteria maps are standardized with a Fuzzy linear function and the ANP model was run in Super Decisions software, and pairwise comparisons and related super matrices were calculated for the criteria and the relative weight of each criterion was obtained and the resulting weights were applied to maps. Finally, the weighted maps were combined each other using the 0.9 fuzzy gamma operator, and the Fuzzy ecotourism capability zoning map was produced in value 0 to 1. Results and Discussion After designing the network structure, matrices and related super-matrices were calculated and the relative weights of all criteria were determined. Results showed that temperature, geological structure, slope, rain, and tourism facilities have the most importance and weight in relation to the ecotourism ability of the study area, respectively. According to the ecotourism capabilities zoning map, the study area was divided into four class: completely suitable, relatively suitable, relatively unsuitable, and completely unsuitable. The resulting map analysis shows that areas located in the central and western parts of the region, which have a low slope percentage and also include rich pastures and natural tourist attractions, are in the completely suitable group. Furthermore, some parts of the study area have mountain slopes and difficult topographic conditions that are very difficult to access grouped in completely unsuitable lands for ecotourism activities. The final results of the study show that 14.50% of the study area is in the completely suitable class, 26.32% in the relatively suitable class, 27% in the relatively unsuitable class and 32.15% are in the completely unsuitable class Conclusion Research evaluations show that In general, Margavar rural district, both in terms of potential for the future development of ecotourism and in terms of Its current situation has a lot of potential in this regard in terms of receiving a large number of tourists That comprehensive planning and formulation of effective solutions in this field can be considered an effective way and an important step to achieve sustainable regional development. Application of multi-criteria analysis techniques such as ANP model and Fuzzy model in this research indicates the great flexibility of these methods, which makes it possible to determine different scenarios and combine different criteria with each other. On the other hand, the use of GIS has provided a good platform for feasibility studies, assessment, and identification of the natural environment. Therefore, it can be said that due to the high potential of the Margavar rural district, there is a need to review measures and pay more attention to tourism development plans and studies in this region.
Geomorphology
Mohammad Hossein Rezaei Moghaddam; Davod Mokhtari; Majid shafieimehr
Abstract
Introduction
Proper management of catchments is one of the most important ways to make optimal use of water and soil resources. In our country, most of the catchments, especially the mountainous catchments, do not have enough hydrometric and sedimentation stations. This fact makes any development and ...
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Introduction
Proper management of catchments is one of the most important ways to make optimal use of water and soil resources. In our country, most of the catchments, especially the mountainous catchments, do not have enough hydrometric and sedimentation stations. This fact makes any development and management plans difficult. Hydrologists and water resources researchers have come up with various solutions but none of them have been completely successful (Roustamiyan et al., 1999; 588 & Shaygan et al., 2011; 2). On the other hand, the limited methods of measurement in hydrology and the need to have a method to generalize the available statistics to areas without statistics or places where measurement is not possible. Also, simulating future hydrological changes is one of the main reasons for hydrological simulation (Beven & Binley, 2001; 46). The ability of the SWAT model to simulate the complex hydrological processes of watersheds in the GIS environment distinguishes this model from integrated models in which larger user units are the basis of operation.
Data and Method
The study area is part of the Qizil Üzan River. Shahar Chai basin along with other rivers such as Zanjan Chai, Aydughmush, and Qaranquchay is one of the sub-branches of Qizil Üzan that flows northwest and north of the basin and joins near the Myaneh city. The data used in this study include a digital elevation model of 1: 10000 of mapping organization, land use, soil, precipitation, minimum and maximum temperature, wind speed, solar radiation, relative daily humidity of synoptic stations, Sarab, Heris, Bostan Abad, Charoymaq and Runoff and the sediment of Shahar Chai station. In the watershed of Shahar Chai, a soil map prepared by natural resources of East Azerbaijan province has been used. Based on these maps, 21 soil texture classes can be distinguished in the whole basin. Also, based on the land use map, six land use classes in the area were identified.
Results and Discussion
After parameterization and data entry, the simulation was performed for 20 years from January 1, 2000, to December 31, 2019, based on a monthly time step. To determine the degree of sensitivity of flow parameters in the SWAT model, sensitivity analysis was performed using the SUFI-2 method for 25 selected runoff parameters and 15 selected sedimentation parameters. Using validation results to remove parameters that are less sensitive from the calibration process, it is decided that finally the parameters with lower sensitivity were removed and 13 parameters for runoff and 7 parameters for sediment were selected that were more sensitive. The calibration model for runoff and sediment was done in one step with 1500 simulations in three replications. The calibration process ends when, based on the objective function, the coefficients required for evaluation are acceptable. According to the obtained results, all the evaluation criteria of the model in the simulation of runoff and sediment are allowed.
Conclusion
Examination of the results of the SUFI-2 method in the Shahar Chai basin showed that, based on the evaluation criteria of the coefficients of determination and Nash-Sutcliffe, both in the calibration and validation stages, it has good results in this basin. But they can't predict peak discharge and sediments well. To better determine the performance of the model, first of all, it is recommended that the statistics of stations and numerous and daily runoff and sedimentation measurements should be used instead of monthly, if any, in a basin, to compare their results. Secondly, to achieve the desired results, this model should be used in comparison with other simulation models in this basin and adjacent basins.
Geomorphology
somayeh karimi; Masoumeh Rajabi; Mohammad Hossein Rezaei Moghaddam
Abstract
Introduction Soil erosion is a process of moving soil by water or wind - when the soil particles are detached and is one of the main forms of soil destruction around the world which restricts sustainable development of the earth resources by creating negative environmental effects (Marques et al, 2018). ...
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Introduction Soil erosion is a process of moving soil by water or wind - when the soil particles are detached and is one of the main forms of soil destruction around the world which restricts sustainable development of the earth resources by creating negative environmental effects (Marques et al, 2018). Every year more than 75 billion tons of soil is eroded from the earth's surface which is amounted to 134 tons per square kilometer (Sobhani, 2002,18). In Iran too nearly 2 billion tons of valuable soils are lost annually and damages resulted from soil erosion is amounted to 56 billion dollar (Gholami, 2002,20). Karst areas have their special conditions due to their special hydrological and geomorphological conditions. Alvand basin is a distinguished karset basin in the west of Kermanshah province and the problem of soil erosion has existed in this basin for long time and exerted destructive effects on the environment. It is feared that by continuing current trend and its intensification due to human activities and destruction of oak forests, this basin faces with stone desertification in addition to disturbance in karst water resources and hydraulic constructions of the basin face with problems resulted from sediment. Meanwhile no study has been conducted in the Alvand basin surface to assess soil erosion by taking in to account karst condition, then conducting this research is essential and necessary. The goal of this study is to evaluate and zone soil erosion by taking karst geomorphological condition in Alvan basin in to account. Methods and materials Library, descriptive-analytical, field methods as well as SMLRK model were used. Above model includes influential internal parameters (infiltration, erodibility and morphology) and external parameters (land use and rainfall erosivity). In this study above model is conducted in two modes with and without involvement of infiltration parameters. For verification of the maps error matrix of two maps were calculated. Research data includes Landsat satellite image, 10 meters DEM, geological and pedological map and rainfall data from climate stations of the region. Results and Discussion In the zoning map obtained from equation (5) infiltration parameter which covers karst aspects has been neglected (Fig.7). Classes with low and very low erosion constitute 44.68% of the basin area, class with moderate erosion 21.9% of the basin area and classes with high and very high erosion 33.4% of the Alvan basin area. Totally, nearly 55% of the Alvand basin area is exposed to the risk of moderate to high soil erosion. Low erosion class conforms to plains’ surface and hilly regions of the basin. These regions generally have agricultural and rangeland and semi-dense forests use. Texture of the soil in these regions is heavy with lot of mineral materials and very deep. This karst class morphologically has low sleep and the directions are back to the sun and are less in the realm of the karst regions. Zone with moderate erosion conforms to erosive plains in the west of the basin, hilly regions and low hillsides of the zone’s mountains. The usage of these regions is usually rangeland- forest and includes parts of the karst regions of the basin. From morphological point of view, it has medium slope and soil texture is moderate with mineral materials and moderate depth. Zone with grate erosion exists both in karst and non-karst areas. These regions are usually steep and have rangeland and thin forest use with light soil texture and shallow. Karset regions are located in Sirvan, Ghalaje, Sarkesh, Deh Nooshak, Navakooh and Dalahou heights. Highly erosive zones conforms to rocky and steep regions with thin rangeland use, soil texture is light and very shallow (Fig.7B). Low and very low erosive zones occupied 38.75% , moderate erosive zone 29.86% and high and very highly erosive zones 31.37% of the Alvan basin surface (table. 8). Land use, morphology, geomorphological, rainfall and soil condition in each of these zones is the same as erosive zones of the previous map. Conclusion In SMLRK model unlike most common models, karst geomorphological conditions have been involved in its sub-parameters. In this research final map of the erosion results from this model has been provided in two ways with and without involvement of the infiltration parameters. In the final maps of the soil erosion obtained from two methods, there are five erosive zones. Providing soil final erosive map for the Alvand basin using infiltration parameters causes changes in the surface of the erosive zones and their special distribution. With involvement of the infiltration parameters in modeling soil erosion of the Alvand basin, surface of low and high erosive zones in the map with five factors compared to the soil erosion maps with four factor has decreased and surface of the very low, moderate and very high erosive zone has increased 2.04%, 7.96% and 5.98% respectively. In order to evaluate exactitude of the obtained maps their error matrix and similarity degree were calculated (Table 9). Accordingly, two maps and their classes were compared based on pixel and total sum of table diagonal is divided to total sum of the tables which expresses similarity degree of two maps. Similarity degree between two maps is 54.85% which reflects the main effect of infiltration parameter in amending result. Indeed, karst developed areas in east and north heights of the basin with involvement of infiltration parameter are located in highly erosive zone. Therefore, karst zoning results obtained from involvement of the infiltration parameter and consequently karst geomorphology have better performance and the results of this mode of model reflects more soil erosion in the area having karst geomorphology.
Geomorphology
Mohammad Hossein Rezaei Mogaddam; Mohammadreza Nikjoo; Davod Mokhtari; Ahmad Fakeri Far; Kazem Koshdel
Volume 22, Issue 64 , September 2018, , Pages 81-101
Abstract
The streams of rivers are extremely complex in nature. Rivers are beneficial for natural vegetation, animals, living organisms and human communities. The river provides the possibility of drinking water and irrigation of agricultural fields. Rivers are considered as active land cultivators with erosion ...
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The streams of rivers are extremely complex in nature. Rivers are beneficial for natural vegetation, animals, living organisms and human communities. The river provides the possibility of drinking water and irrigation of agricultural fields. Rivers are considered as active land cultivators with erosion and sedimentation. Some of the negative effects of rivers such as floods are considered as a natural disaster. Such natural disasters have been shown when the river by anthropogenic activities by changing the shape of the river and arched their plans change. Meandering parts of the rivers are vulnerable to floods. Therefore, river studies are very important in terms of hydraulic characteristics, sediment, width to depth ratio, morphology and arched plan. Kaleibar Chai basin has located on the North West of the country. This research pays attention to the arcuate plan of Kaleibar River from the city of Kaleibar to Jananloo village (one of the branches of Aras River). The study region is part of Kaleibar Chai River with 72 km of length. The channel consists of right, waving, meandering, and braided patterns. The study of horizontal plan of the river in relation to different active processes shows the mutual relationship between hydrological parameters and the materials in the river. The continual changes in sinuosity index in the channel are indicators of variations in the river behavior. For doing this research we used Google Earth and DEM 10m images. The river was divided into 4 openings in which topographic conditions were considered. The river sinuosity index was calculated for all 4 openings in GIS software under the formula: TSI= . In this equation TCI is topographic sinuosity index, CL is the length of the river channel, Al is the aerial length of the beginning and ending part of the channel. The maximum sinuosity index for different lengths of the Kaleibar Chai River was estimated at 1.05 to 1.83. The heterogeneity of bed materials causes erosion and deposition on the river bed of Kaleibar Chai. Erosion and depositional processes occur in the area during the spring and fall floods. The variety of materials and their sizes cause erosion and the collapse of the brinks and the loop in sinuosity index, which finally lead to channel changes. The study of sinuosity index and the identification of rivers patterns help ease the planning procedure
Geotourism
Mohhamadhosen Rezaei moghadam; Mohamadreza Nikjou; Kamran KHalilvalizadeh; Belvasi Imanali; Mehdi Belvasi
Abstract
Landslide is one of the natural hazards in mountainous regions that results in huge losses every year. Alashtar Doab watershed with mountainous terrains, uplands and different natural conditions has the potential for landslide. The purpose of this study is landslide hazard zoning using artificial neural ...
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Landslide is one of the natural hazards in mountainous regions that results in huge losses every year. Alashtar Doab watershed with mountainous terrains, uplands and different natural conditions has the potential for landslide. The purpose of this study is landslide hazard zoning using artificial neural network model in Alashtar Doab watershed. In order to preparing the map, first of all parameters of the landslide were extracted and then the layers were prepared and after that a landslide distribution map that was occurred in the basin was prepared and then by combining landslide influencing factors with landslide distribution map, the impact of each of these factors such as slope, aspect, lithology, rainfall, land use, distance from fault and stream in ArcGIS software were measured. In this research, artificial neural network model with error back propagation algorithm and sigmoid activation function was used. The final structure of the network consisted of eight neurons in the input layer, eleven neurons in the hidden layer and one neuron in the output layer. Network accuracy in the testing phase was calculated by 85.93 percentages. After optimization of the network structure, all area information was imported to the network. Based on landslide hazard zoning using artificial neural network model, 37.44, 45.7, 93.8, 49.32 and 76.6 percent of the area at risk is located in very low, low, medium, high and very high classes, respectively.
Geomorphology
Somayeh Khaleghi; Shahram Roostayee; Ali Mohammad Khorshiddoost; Mohammad Hossein Rezaee Moghaddam; Mhammad ali Ghorbani
Abstract
Catchments and river systems altered in response to changes of internal and external factors. Hence, several techniques have been proposed to simulate these changes and Evolution of the river systems. Cellular Automaton is one of the newest river cellular models that define the catchment landscape with ...
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Catchments and river systems altered in response to changes of internal and external factors. Hence, several techniques have been proposed to simulate these changes and Evolution of the river systems. Cellular Automaton is one of the newest river cellular models that define the catchment landscape with a grid of cells, and development of this landscape is determined by the interactions between cells (for example fluxes of water and sediment) using rules based on simplifications of the governing physics.This method is used for simulation of Lighvan catchment with 20 m cell size and 10 years precipitation data (1380 to 89). Simulation results evaluated in two qualitative and quantitative methods, So that the relative changes in the catchment and spatial distribution of erosion and aggradation value in the entire catchment and each cell was identified on Digital Elevation Model map and also, values of different particle size distribution in different discharges showed that with the increasing discharge, and amounts of sediment increased and among this coarse sand have the highest value and very fine sand, clay and silt particles have the lowest value. Also investigation of longitudinal and latitude profile show that Lighvan river is in mature stage and Lighvan channel has been underwent aggradation due to climate changes and increasing catchment precipitation in last decade that causes hillslope erosion and channel aggradation. Finally, Since certainty of Cellular Automata results is difficult and CAESAR is sensitive to input parameters but comparing the results with previous investigation and field observation shows that Cellular Automata has acceptable results.
Climatology
MohammadHoseein Rezaei Moghaddam; Khalil Valizadeh Kamran; Mehdi Belvasi; Hoseein KheiriAstiyar; Sayad Asghari Saraskanroud
Volume 20, Issue 56 , August 2016, , Pages 127-148
Abstract
One of the most important procedures in the water sources studies is the estimation of the local distribution of precipitation in different time scales. The study of precipitation is a basic element in the water balance studies and is an important factor in the natural sources programs of each country. ...
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One of the most important procedures in the water sources studies is the estimation of the local distribution of precipitation in different time scales. The study of precipitation is a basic element in the water balance studies and is an important factor in the natural sources programs of each country. Also, because of the rain-evaluation stations deficiency and their discreteness, it is necessary to use a special model. Besides the interpolation of precipitation amounts of stations, this model should interpolate topography, moisture and the slope direction of precipitation. In this work, at first, some data were gathered, in one year. These data were connected with the precipitation and moisture of 9 synoptic stations and 31 rainevaluation stations. These stations were located in the Lorestan province. Second, using the least square method and with the help of Maple software, the relations between precipitation and moisture was extracted. Third, by using the Python programming language, these relations were linked into the GIS. Finally, by so doing, the digital precipitation modal was achieved. The results obtained from the digital precipitation model show that, the precipitation amounts are different from the measured data in the stations, from 0.02 to 11.6 mm. Also, to investigate the efficiency of the considered model, the data obtained from this model were compared with the precipitation data achieved from TRMM radar at 21 April 2010. The concluded result show that, the determination coefficients are 79 and 86% for the TRMM data and for the digital precipitation model, respectively
Geomorphology
Mohammadreza Rezaei Moghaddam; Khalil Valizadeh Kamran; Soghra Andaryani; Farhad Almaspoor
Volume 19, Issue 52 , June 2015, , Pages 163-183
Abstract
Land use and land cover maps are necessary for planning and natural resources management. In the way, remote sensing data have special place because of providing update data, repetitive covers and low cost images. Therefore Optimum Land Image/ Thermal Infrared Sensor were used to map land-use and land-cover ...
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Land use and land cover maps are necessary for planning and natural resources management. In the way, remote sensing data have special place because of providing update data, repetitive covers and low cost images. Therefore Optimum Land Image/ Thermal Infrared Sensor were used to map land-use and land-cover in 1 and 2 level. Because of, this images are new thus radiometric correct was used ERDAS software model maker. Also Normalize Difference Vegetation Index (NDVI), Bare Soil Index (BI) and Principal Component Analyze (PCA) were used as inputs to improve classification accuracy. On the other hand kernels functional and polynomial ranks of Support Vector Machine method evaluated in side others bands and the best result of SVM method compared with Artificial Neural Network (ANN). The results indicated that SVM method has accuracy: 92% with Kappa Coefficient: 0.91 and ANN method has accuracy: 89% with kappa coefficient: 0.87 also SVM method has a good performance in the regions that, classes show similar spectral behavior.
Volume 19, Issue 52 , June 2015
Abstract
Preparing landuse and vegetation cover in planning and management of natural resources is very important. For this aim, using remote sensing data has important role especially because of daily cover and low cost images. So in this research, Landsat 8 images are used as input data for extracting landuse ...
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Preparing landuse and vegetation cover in planning and management of natural resources is very important. For this aim, using remote sensing data has important role especially because of daily cover and low cost images. So in this research, Landsat 8 images are used as input data for extracting landuse map in levels 1 and 2. Images with respect to newly issuing are correcting radiometric by using relationships in ERDAS software's modeling formulation environment. Also, NDVI , BI and PCA as input beside other bands are used for increasing classification. SVM is evaluated and it’s the best result compared with ANN. Results have been shown SVM with 92% accuracy with Kappa Index 0.91 and ANN with 89% accuracy with Kappa Index 0.87. SVM have better result than ANN in all places which classes have same behavior.
Mohammadhossein Rezaei Moghadam; Nooshin Pirouzi Nejad
Volume 18, Issue 47 , April 2014, , Pages 109-132
Abstract
River channel change, such as bank erosion and accretion are natural processes in alluvial rivers. This paper aims to investigate migration and channel change plan form and effect on bank erosion and accretion done in Gamasiab River in Kermanshah Province. This study used aerial photography taken ...
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River channel change, such as bank erosion and accretion are natural processes in alluvial rivers. This paper aims to investigate migration and channel change plan form and effect on bank erosion and accretion done in Gamasiab River in Kermanshah Province. This study used aerial photography taken in 1955, 1969, 2003 and IRS satellite imagery of 2010 with a resolution of 5/8 m, aerial photographs were orthophoto in ARCMAP software based on 1/25000 topographic map. Shoreline was digitized and river was divided into 12 reaches. By comparing river in the sequence period investigated the positions have a change. Using the ARCMAP software to create polygons that represented the difference between two positions we calculated erosion and accretion separately for each side of the river. The area of bank accretion along the river had been 285.5 ha and from 1955 to 1969 this area had been 402.6 ha from 1969 to 2003 and the area of bank accretion was 112.9 ha from 2003 to 2010. Bank erosion had been 347 ha from 1955 to 1969, and this was been 414.17 ha from 1969 to 2003 and the area of bank erosion had been 138.2 ha from 2003 to 2010. Results show that the amount of bank erosion is more due to bank accretion in the Gamasiab River. Change and migration in river is the cause of the erosion. Some places in river show about 400 m of movement.
Mohammadhosein Razaeemoghadam; Adel Mohammadifar; Khalil Valizadeh
Volume 17, Issue 44 , September 2013, , Pages 161-178
Abstract
Most of water structures and land uses being rivers or in rivers banks are somehow influencing morphological changes in rivers. Therefore survey of this phenomenon is considered as the most important part of studies projects and land uses. In this study part of the AjiChayRiver has been studied between ...
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Most of water structures and land uses being rivers or in rivers banks are somehow influencing morphological changes in rivers. Therefore survey of this phenomenon is considered as the most important part of studies projects and land uses. In this study part of the AjiChayRiver has been studied between Khaje and Vanier with about 22 km length. The main aim of this study is indicating trend of morphological changes in the river, in 52-years period using the geometric parameters of the channel such as arc length, along the river valley and radius of the river circle tangent arc in the form of models the curvature coefficient and the central angle. For this purpose river path from satellite image IRS sensor Pan and aerial photos for years 1956-1995 and 1995-2008 in the ArcGIS environment in two intervals and two periods were digitized and calculated. Causes of changes using the topographic maps 1:50000 and geological 1:100000, hydrological data and field methods were investigated. Results show that 1) river on average in both periods and in both interval of their arch curvature is reduced. So that the central angle in the first interval of 137 to 100 degrees and the second interval of 160 to 148 degrees and curvature coefficient in the first range of 1/133 to 1/15 and the second period from 1/48 to 1/27 is reached. Also numbers of arcs in the years 2008 to year 1956 have increased making the year 2008 the first range number of arcs of 11 to 51 and the second interval of 19 to 86. No observed meander-like and horseshoe (oxbow) pattern on the river exists. Morphological changes of AjiChayRiver in the timeframe and location studied have been affected by natural factors such as loss of power of flow due to reduction of annual average water discharge and sediment, accumulation of sediment and erosion.
Mohammad hossein Rezayee Moghadam; Mohammad reza Servati; Sayyad Asghari Serkanrood
Volume 16, Issue 40 , September 2012, , Pages 119-139
Abstract
Researchers of river Geomorphology science are seeking new ways to check River Geomorphology and its pattern changes always. Fractal geometry is one of the new methods that can be used in Geomorphology of river science. The main importance of fractal geometry is presentation of the model and mathematical ...
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Researchers of river Geomorphology science are seeking new ways to check River Geomorphology and its pattern changes always. Fractal geometry is one of the new methods that can be used in Geomorphology of river science. The main importance of fractal geometry is presentation of the model and mathematical description for complex shapes that in nature can provide. The goal of this research is Fractal analysis of GezelOzanRiver changes between routes of Miyaneh to Zanjan. For this purpose was used satellite images of periods 2000, 2004 Sensor ETM + and 2007 sensor IRS. For Fractal analysis the studied route was divided into three periods that each period is different in terms of morphological characteristics. For determine of fractal dimensions was used from box-counting method. The survey results showed that the first interval (interval arterial) has had the highest changes and the second range (Mid-range Mountain) has had the lowest changes and third period (mountain range) has had an intermediate case.
