Environmental Erosion Research Journal

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In this study, the exact area of the Khuzestan sand dunes was first drawn and then classified in terms of morphology. Next, the dynamic state of the Khuzestan sand dunes was evaluated, and then the relationship between the speed and direction of the region's winds and the morphology and dynamics of the sand dunes was analyzed. The results of this study have shown that the Khuzestan Sand Dune, with an area of 2629 square kilometers, consists of various forms of sand dunes. The results of the analysis of the status of the Khuzestan Sand Dune activity have shown that about 43 percent of its area is covered by active areas, and in total, the Khuzestan Sand Dune sand dunes have moved between 1 and 55 meters under the influence of various natural and human factors during the years 2005 to 2020. Also, the results of the analysis of the winds in the region have shown that high wind speeds in some seasons, including spring, play an important role in the movement of sand dunes, and different wind directions have also caused the morphological diversity of the sand dunes in the region. Also, human activities, including the stabilization of sand dunes by vegetation, have caused sand dunes to remain stationary in many areas, despite the availability of conditions.

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Erosion means the harvesting, transportation and movement of eroded material .The concept is very extensive erosion that has different definitions in different disciplines. The purposes of this paper is finding a brief definition of “erosion” concept in different perspectives and comparing it in Geomorphologic and Natural Resources point of views. To achieve this goal, we try to use the library documents, analyze and compare the findings of this work with each other. Results show that most differences between these approaches, different time, place, is corrosive agents and erosion processes. In Geomorphologists view of point,erosion is a natural phenomenon and Sformation of it is slow and makes landscapes and landforms that are environmental resources suitable for human life. But the erosion in the point of Natural Resources Science view is destruction of fertile soils and have negative effects on the lives of many inhabitants of the plan. Natural Resources Science specialists believe that soil erosion phenomena even is a destructive force for civilizations. General concept of erosion according to the type and scope of the study has significant differences from the perspective of Natural Resources Science and Geomorphology.

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Rivers have a complicated and various condition in the diverse environment, and various science such as Hydrology, geomorphology, hydraulic, ecology and engineering have it been discussed. River geomorphology with studying of river process and landforms, examination of river landscape evolution, can be playing an important role in identifying of river channel character and behavior. To order that river has been examined precisely and damage to property and river engineering designed declined.In this study based on River Style framework, first type of river style is determined. Then, with three degree of freedom channel morphology, planform and river bed character, capacity for adjustment, and relevant geoindicators for each degree of freedom for each river style are determined. Next, river evolution interprets using with ergodic reason to assess whether irreversible geomorphic change has occurred and geomorphic recovery potential of each reach is determined by assessing the connectivity of reaches and interpreting limiting factors and pressures.In Lavij rud catchment eight river style identified. More steep headwaters have intact condition and gorges, low sinuosity planform with discontinuous floodplain and high energy with gravel bed river styles have high river recovery potential. Cut-fill, bedrock controlled with discontinuous floodplain and confined with occasional pocket floodplain river styles have moderate river recovery potential. Confined with slump bank river style have a low river recovery potential and their condition are degraded. Results show that river styles in this catchment also have respectively 65, 28 and 7 percent high, moderate and low river recovery potential. Management prioritization each river style proposed to notice river geomorphic condition and river recovery potential.

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The river’s Geomorphology and its evaluation explore explanation of erosion, the longitudinal profile of the river bed and different forms of the rivers. Alvand River as the main river of the Alvand basin is located in Kermanshah Province W, Iran. The aim of this study is to investigate changes in longitudinal and longitudinal profiles of the river bed using mathematical functions and their relationship with the land and its base. Using the Applied-Developed research method, analytical-statistical and field study method is used in this paper.The results show that, the evaluation of longitudinal profiles and morphological forms of the river bed is in relation with various factors such as erosion, tectonics, lithology and geomorphological elements such faults. The rivers located in the upper part, are fitted with a linear function due to this part of the basin is affected by activities tectonic. The middle and low parts except Alvand 2 which are affected by tectonic activities, other parts due to tectonic activity on weak lithologycal structure, have been fitted with an exponential function and contains bed and bank erosions.

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The river’s Geomorphology and its evaluation explore explanation of erosion, the longitudinal profile of the river bed and different forms of the rivers. Alvand River as the main river of the Alvand basin is located in Kermanshah Province W, Iran. The aim of this study is to investigate changes in longitudinal and longitudinal profiles of the river bed using mathematical functions and their relationship with the land and its base. Using the Applied-Developed research method, analytical-statistical and field study method is used in this paper.The results show that, the evaluation of longitudinal profiles and morphological forms of the river bed is in relation with various factors such as erosion, tectonics, lithology and geomorphological elements such faults. The rivers located in the upper part, are fitted with a linear function due to this part of the basin is affected by activities tectonic. The middle and low parts except Alvand 2 which are affected by tectonic activities, other parts due to tectonic activity on weak lithologycal structure, have been fitted with an exponential function and contains bed and bank erosions.

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Considering the most of country have no gage station, in recent year one method can be proposed with the involvement of other information, which will affect hydrology condition. It can estimate flood water level. In this study, considering relationship between geomorphology and hydrology, using little information, flood hydrograph were simulated. This method is named geomorphological instantaneous unit hydrograph (GIUH). At first, the drainage basin was ranking using Strahler method. Then, the quantitative geomorphologic parameter concluding ratio of bifurcation (RB), ratio of area (RA), ratio of length (RL) and length of last order (L&Omega) were calculated considering this ranking. Then using these parameters and the peak flow velocity in outlet, peak discharge in outlet and time to peak of instantaneous unit hydrograph were calculated. For model evaluation, five events were selected from hydrometry station in outlet of basin, compared with computational hydrograph using GIUH model. Result show that, this model is suitable for this area, and little difference between observed and computed hydrograph was due to construction of earth dams in upstream, which affect hydrology conditions.

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Darab Plain is among region that in there formed several alluvial fans because presence of situation and climate change, and can mention to Katoeh, Rigabad and Chenar alluvial fans. In this research is tried to using of Geology and Topographic Maps, Arial Image ana Field survey analysis are discussed  Factors affecting the establishment and evolution of this alluvial fans. Result showed that Katoe and Chenar Rivers have high pure force because sharp steep of bed and increase of velocity, and is Prevailing practice of digging the river bed because excess of force that was transfers the downstream materials from erosion. This agent was caused formation of case study alluvial fans. Alluvial fans morphology of Katoe and Chenar has the unique feature. because deposition act don’t in an open space by Katoe and Chenar rivers, but was limited the left side of katoe alluvial fan by Noro mountain and right side of Chenar alluvial fan with Barfdan Mountain. Also human disarranged natural order of case study alluvial fans evolution with creation of artificial embankments, and sand removal

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Changes in a river's geomorphologic pattern would be considered in all environmental plannings because this change has special consequences on land ownership properties, the use of cultivable lands on rivers' banks and supply of constructional materials. Sand and gravelmining of the river beds are among factors that lead to changes in river bed patterns. In this research, we investigate geomorphological changes in sections of Kashkan River in Khoramabad County from Kashkan Ancient Bridge to Cham Davood Village, approximately 14 km distance. There are three sand and gravel mining sites in this short length of river which have caused major changes in the bed and banks of the case study river. We used a temporal resolution aerial photos of 1381 (A.H.) and Cartosat images of IRS by 5 meter resolution of 2009 of the study region. We used ARC/GIS, AutoCAD, and Global mapper to calculate and measure geometrical parameters that changed during this time period. By comparing spatio-temporal changes, results showed that sand and gravel mining was a major factor of about 50 percent of changes that occurred in the study area. River dynamic, bridge and curving dams’ construction in the river course were other factors of changes.

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The dimensions, shapes and the patterns of natural rivers change according to their dynamic properties. These unavoidable changes cause the rivers imbalance and a new balance will be formed.  The around lands will be affected by this dynamic and dangers such as instability of the bed. In this research we used chronological inference method to study Kashkan River morphology. Kashkan river is located in a region between Lorestan province and Gavmishan bridge in a reach of 25 kilometers. The aero photos of 1334, 1376, the sensing images of liss3 obtained from IRS P6 satellite in 1385 and the Geo Eye image of the land were digitized in Arc GIS software. In the second step geometrical parameters such as wave length, valley length, sinuosity, central angle and radius tangent on the river arch were calculated. Then these geometrical parameters were statistically analyzed and were compared in 4 stages. We Using HEC-RAS investigated flood zonation as an important factor in river bed changes. The results of this study and comparing these parameters during the 4 reaches showed that in the abovementioned year s kashkan river pattern was meandering in the reaches of 1, 4 and 5 and also it was developed meandering form in the reaches of 2 and 3. Those river’s arcs which had the most changes in those years were located in the reaches of 2 and 3. At the end it was concluded that the geology factor and the river’s flood in the reaches of 2 and 3 were the most important factors in forming the bed’s changes and bank erosion. Topography factor was the most important factor in causing the most changes in the reaches of 2 and 3 which were located in floodplain.

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Landform is a complication of land or landscape the establishment of which is formed by natural processes that can be described and defined by diagnosis index and if detected, the Landform information about their structure and composition, texture or its integrated offers. Landform variety and diversity of participants, mainly by changing the shape and position of the controls placed. So, classify and identify different areas according to their morphologic characteristics is essential. This study attempts to classify different Landform in the Hakan Watershed, Jahrom City. This research is Descriptive - analysis based on quantitative methods, field and modeling software Where the TPI method were used for the identification and classification of Landforms the study area. The model input data, including slope, curvature width, curvature minimum and maximum curvatures. The results of the study showed that the morphological classification of the study area includes 10 Landform (stream, mid-stream valleys, drainage, high, u-shaped valleys, plains, small, open slopes, steep upper edge high, middle edge of the slope, the high ridge, mountain).

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Predictions of total and even partial changes in rivers patterns are as the most essential issues related to rivers geomorphology. In this regarding, a lot of researches have been done by geomorphologists. This research has explored Kordan River aqueduct morphology changes in bights areas of Afkaneh cone surface. Kordan river is the one which has been affected by various factors and has changed a lot so that this changes has impressed on components an human activity around the river and on side erosion and channel. The research method is on analytical and time comparison method by which direct and indirect observations, maps and images are used, to the drainage characteristics in the two study periods. In this research topographic maps at 1:25000 scale and photogrammetry at 1:55000 and 1:40000 scale of studied region was used. Beside these, to exploit sack changes some software application such as Arc GIS , Excel and SPSS were applied. Research results show that river side changes in 37 to 165m are varied in river different parts that in average, river has gotten eroded 31583.4 m2 in 44 years that annual erosion amount has been 718.8 m2. It can be predicted for further 20 years that probably right side of the river will get eroded 14415 m2 in average. In 1999, developed and non-developed bights were added to river area, and high developed bights have been reduced from river than 1955. According to Leopold and Wolman index, bend coefficient more than 1.5 has bight pattern, therefore in studied bight parts of Kordan river 90% of bows has had evolved bight pattern in 1955 and this amount has arrived to 81% in 1999. Regarding to calculation, it can be concluded that bights had been increased from 1955 to 1999 but their sharpness were decreased.

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Recognition of growth pattern and folding mechanism in the fold-thrust belts with hydrocarbon resources is important in exploration and development planning of oilfields. As the processes of tectonics, erosion, and geomorphology impact on each other, therefore, the investigation of a process, one can obtain information about the other process. In this research the tectonic process of transverse growth of fold, was investigated based on the erosion pattern of the streams on the fold limb and geomorphological and hydrological indices in the Khaviz oilfield which is located in the Dezful Embayment. The results of investigation of the erosion pattern of the streams and the indices showed that the fold growth pattern in this oilfield in the south limb is limb lengthening through the toe and in the north limb is lengthening through the crest and toe.

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Extended abstract

1. Introduction

The vital need for river management is understood and predicts bank erosion processes. River bank erosion is one of the sediment major sources for many rivers across the world. Bank erosion is a key process in fluvial dynamics, affecting a wide range of physical, ecological and socio-economic issues in the fluvial environment. These include the establishment and evolution of river and floodplain morphology and their associated habitats, turbidity problems, sediment, nutrient and contaminant dynamics, loss of riparian lands, and associated threats to flood defense and transportation infrastructure. Moreover, recent studies have shown that the contribution of bank-derived sediments to catchment sediment budgets may be higher than what previously thought. The study of the factors influencing Bank Geomorphology and Erosion requires basic information on geological, hydraulic and geometric characteristics. Therefore, the main aim of this paper is to study the stream banks susceptible to bank erosion in Bashar River.
 

1. Methodology

 
2-1- Geometry and Morphology of Beshar River
 In order to understand the mechanism of the lateral erosion, the morphology of the Bashar River was identified through digitizing the Landsat satellite image in the ENVI software. After making necessary corrections, the geometric properties and the river morphological parameters were determined in the AutoCAD software. The most important indicators used in this study included the central angle of the grunge, the bending coefficient, relative radius and Meandander width and length. To calculate each of the indicators, refer to the guide for river morphological studies.
 
2-2-Geology of Beshar River:
In order to study the geological condition of the  Beshar river, the geology map of Bashar watershed was prepared using a map of 1/400,000 Geological organization; then the map of Bashar's main river was overlapped with the geological formations map and the geological map of the river was extracted.
 
2-3- Shear Stress
The reach of Beshar river with a length of 10-km was selected and the hydraulic, morphologic and geologic characteristics were studied. Then, the critical shear stress was computed using the empirical relations based on the soil parameters.
 
2-3-1- Near-Bank Shear Stress
In order to determine the erosion reaches of Beshar river, shear stress coefficient was used which was calculated according to the ratio of the curvature radius to the river's width.
 
2-3-2-Total Shear Stress
Shear Stress (t) is a measure of the force of friction from a fluid acting on a body in the path of that fluid. In the case of open channel flow, it is the force of moving water against the bed of the channel. Shear stress is calculated as:


2-3-2- Critical Shear Stress



 
2-3-3-Relative Bed Stability Index



 
3- Results
The results showed that Bashar river has more than 100 large and small meander. Curvature coefficient in reach located in the kilometers of 7-14 and 75-85, is equal to 1.4. Critical shear stress index indicated that the reach of Beshar river located in 10km is instable (τ_c> τ and RBS< 1 and FS<1). The results showed that the shear stresses calculated for the east, west and bed cross-sections are instable (facror safety<1). Also, the rate of bed stability index is less than one in most sections. The results inicated that the shear stresses calculated for the cross sections are more than thershold amount. The average shear stress on the eastern and western banks are 8.85 and 14.87 kg / m2, respectively Whereas Permissible shear stresses average in the eastern and western banks are 61.93 and 61.76 kg / m2, respectively. Therefore, shear stress average of the river bank is less than the Permissible shear stress average. Also, the shear stress average of the river bed is equal to 17.44 kg / m2 and the bed Permissible shear stress mean of river bed is 78.17 kg / m2. Therefore, the average shear stress tolerance is lower than the shear stress average on the bed.
4- Discussion and Conclusions
Results indicated that the reach of Beshar River, crossing the silt formations, has a high level of sensitivity to erosion bank. More than 50 km of the Beshar River crosses Asmari formation. The long length of Beshar River contains alluvial sediments, which is located on Asmari formation. The effect of shear stress on the cross-sections of Beshar River indicated that the shear stresses on the riverbed and bank are more than the Permissible shear stress. Also, the bed stability index is less than one, which indicates the instability of Beshar River in the selected reach, which is in line with the findings of Ghaffari et al (2006), who reached similar results in terms of Babol River. On the outer side, the amount of shear stress in the river bank is less than the main channel, so that in the river meanders, the amount of shear stress and the amount of bank erosion increased.

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Extended abstract
1- Introduction
    Granulometric analysis is a common tool used to understand and determine the origin of wind sands, and is applied in desertification studies; to realize such knowledge, the parameters of sand particles size as well as statistical analysis such as mean, standard deviation, kurtosis, skewness, etc. are used. One of the most common types of sand dunes formed by accumulation of sand in desert areas is crescent-shape dune known as Barchan. The most prominent features of such dunes are mobility and lateral movements which transform them into the heart of crisis and threat to the urban and rural residential areas as well as economic, army and communication centers. Barchans are produced in the lands where the sand fails to fully cover the surface area and the wind action is predominant from one direction. The main location of Barchan dunes is between the original wind source and the main dune concentration areas. They are crescent-shape, and possess two "horns" that face downwind and two gentle and sleeper slopes. There is a ridge in between the two slopes. Barchans are produced by the moving sands, appearing convex, and wind action predominately from one direction, and might gradually migrate. The most prominent features of this phenomenon are mobility and lateral movements with specific annual trends.
3- Methodology
   The research have investigated the granulometric characteristics of 7 barchans in Pashuiyeh, western Lut. Up to 42 samples have been taken from different parts of the dunes. These parts are right horn, left horn, lee slope, two samples from windward slope, and the crest. From each sample, 100 g of sediments have been separately sieved by the shaker, and then weighed, and the measurements have been transferred into GRADISTAT to analyze the data. In this step, various coefficients and granulometric components of the grains, such as K2f coefficient (chromobin sorting index), percentage of component particle size, uniformity or alignment, middle, faces, mean particle size, bending and stretching of particles using statistical relationships of Folk and Ward (1957) were applied.
4- Results
   The greatest mean size belongs to Barchan number 3 (2.502 j). This is because the dunes are located in alluvial fans. The greatest proportion of particle size refers to sand particles. All dunes have good sorting and due to fine grained particles they have also a sym­metrical skewness. All Barchans, from the origin point of view are single-origin with a relatively good particle size and the type of texture in all is sand. The components of Barchans are all single-origin (Single-origin grain stipulates that the sediment, the water, or the wind were single-origin). Flooding from the mountains of the west to the Yardang creates streams in the region with fine-grained sediments which form a part of the sedimentation of the Barchans. For this reason, the chromaticity coefficient is based on the river sediments. The statistical results indicate that Barchans number 1 and 6 are more of a microfiber. Barchan number 6 is smaller than all the others which might be attributed to the fact that it can be split from asymmetrical Barchan behind it. Barchans numbers 2 and 7 contain the highest amount of sand. The reason of this very fact in Barchan 2 might be attributed to the tilled and abandoned farmlands around the village. These lands, which have destroyed the hard surface of the desert and are abandoned, provide a very good source of sand accessible for regional wind, traveling from the northwest. Barchan number 7, in addition to being in line with an asymmetrical and large Barchan, is located in the dry path of the streams caused by a large conifer, which provides a lot of sandy sediments for this Barchan. The least amount of sand belongs to Barchans 4 and 5. These barchans are exposed to the dry, large rivers of the area, and therefore, it is provided with more fine-grained sand material, which confirms the presence of mud aggregates and fine-grains. The amount of mud in Barchans 4 and 5 was higher, first, due to the presence of floods stuck behind these Barchans with fine-grained sediments, leading to an increase in finer materials in these Barchans, and second, due to the fact that these Barchans are on the track or behind the cloves, which are generally fine-grained.
4- Discussion and Conclusions
   According to the results, including crumbin coefficient, despite common perceptions of the origin of Barchan sediments, the sediments of under-study Barchans were mostly water and river sediments and due to their location by the end of the alluvial fans, they are mostly fine-grained and mobile. In most of the studies of sand dunes, as it is already known in the background, either types of sand dunes including Barchans is studied in terms of their morphometric and granulometric measurements. Most of these studies consider the source of these desert sand dunes as wind sediments. However, in this research, in addition to the morphometric and granulometric studies of Barchans, the wind sediment element in these dunes was ignored to achieve new results; upon the completion of laboratory and software processes, interesting results were gained which were different from what is attained concerning desert dunes and particle size and grain origins. These results indicate that in the study area, the Barchans have no wind origin but are the results of water and stream sediments. This result, prior to this study, in the desert area of study was unperceivable and the result is achieved through in-depth studies and scrutiny over these sand dunes within the area.

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Extended abstract
1- Introduction
Dust occurrences as natural events are common in arid, semi-arid and desert areas. Investigation of the dust with internal sources in the Khuzestan province including about 15 percent of the dust events coming to the region and the presence of the annual average of 50 times of the internal dust (with the concentration maximum of PM₁₀ particles more than 8000ppm in Khuzestan) is very important. Recently, air pollution due to the occurrence of dust is one of the worst environmental problems in the western and southwestern Iran, especially the Khouzestan province. Dust mineralogy is an important factor in source identification of the particles. In this way, frequency, distribution, mineralogy and morphology of the internal dust and so the depositional centers susceptible to dust production in this province were studied for the first time. The source, generation, transport and sediment of dust have been paid significant attention by the scientific community. Investigations of dust events are important because of the impact of the dust on the environment, particularly on the health and human biological system. The regional dust had negative effects on the health of human life which can cause asthma, bronchitis and lung diseases due to their carrying micro-organisms. Dust causes severe soil erosion, desertification, and a significant reduction in the agricultural production and farming as well. Thus, such a crisis is concerned with economic consequences in the short- and long-term periods. In this way, distribution, mineralogy and morphology of the internal dust and so depositional centers susceptible to dust producing in this province were studied for the first time.
2- Methodology
At first, the frequency and the spatial-temporal data related to the internal dust (Code 07) over the 2009-2015 periods were investigated using 13 synoptic data stations in Khuzestan. 32 TSP samples of dust and 65 sediment sample were taken. Mineralogical study of the 11 dust samples associated with 11 sediments samples were determined by X-Ray Diffraction (XRD) using Philips 3040 PW at Kansaran Binaloud Company in Pardis Science and Technology Park, Tehran, Iran. With regard to morphology studies, Scanning Electron Microscopy (SEM) was used on 20 internal and external dust samples at the central laboratory of Shahid Chamran University of Ahvaz (LEO 1455 VP). Also, grading analysis of the erosional zones using LPSA method and Q10- Q50- Q90% standards were done on 11 samples at the central laboratory in Shahid Chamran University of Ahvaz, Iran.
3- Results
The obtained data shows 406 times internal dust in the studied period. Also, the internal dust has a continuity between 1-3 day(s). Bostan, the northeastern city, with the annual frequency of 78 days, has the maximum, and Izeh and Masjid Suleiman, with the annual mean of 6 days, has the minimum duration of the dust in the province. With regard to time, the year of 2009 and the month of June have experienced the largest amounts of dust. Also, the frequency and duration of the internal-derived dust are compatible with the east-western and north-southern increasing trend. The temperature, height, relative humidity and precipitation indexes do not show the same pattern as the frequency of the internal dust in 2009-June, 2015 period.
4- Discussion & Conclusions
Mineralogical study of the 11 dust samples and 11 sediments samples using XRD shows that carbonates, silicates and evaporates are the main mineralogy composition of the internal dust and the erosional sediments in Khuzestan. Halite and dolomite are considered as the main minerals of dust particles, respectively, in over the 70 and 30 percent of the samples, respectively. Evaporate minerals such as gypsum and halite are found more in the internal dust compared with the external dust coming to Khuzestan. Also, quartz frequency in the internal dust occurrences is about 45% more than the dust occurrences from the neighboring country. In addition, minor minerals such as albite are present in all the samples and the other minerals including gypsum, chlorite, illite, and muscovite are the minor minerals in the dust samples as well. SEM analysis shows that spherical and crystalline shapes are the most abundant ones in the dust with calcite, quartz and halite composition. Grading analysis of the erosional zones using LPSA method and Q10- Q50- Q90% standards, illustrates high amounts of silt particles in the Province. But clay distribution was seen in 10-35% of the samples. 15-24 µm is the predominant grading range in Khuzestan. Mean grading of these samples with about 18.9 µm, is a sign of dust-producing potential of all the desert centers in the Khuzestan province. 

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Extended abstract
1- Introduction
Soil erosion by water is a dominant geomorphic process which threatens food security in most parts of the world .The geomorphic characteristics of a watershed play an important role in watershed hydrology, soil erosion processes and sediment yield. Geomorphic characteristics can be an indicator of soil erosion and sedimentation of a watershed. Geomorphic characteristics of watersheds are classified into linear, relief, and areal categories. Linear characteristics include stream number, bifurcation ratio, stream length and streams order. Relief characteristics include three-dimensional features of the watershed such as hypsometric integral, ruggedness number, and relative relief. Areal characteristics encompass morphological characteristics such as drainage density, stream frequency and watershed shape parameters. Accessibility to Digital Elevation Models and remote sensing data as sediment yield predictors simplify the calculation of the watershed geomorphic characteristics. The purpose of this study was to use the latest capabilities of geographic information system to extract the watershed geomorphic characteristics and determine their relationship with sedimentation in the subwatersheds of Khorasan Razavi province.
2- Methodology
This study was conducted in 22 subwatersheds in Mashhad, Neyshabour and Fariman watersheds in Khorasan Razavi province. In order to select appropriate subwatersheds, the hydrometric and rainfall data for hydrometric and meteorological stations were obtained from Khorasan Razavi Regional Water authority for the selected watersheds. Annual sediment load was calculated using sediment rating curve method. Physiographic and geomorphic characteristics including 30 geomorphic parameters were calculated for each subwatershed using Digital Elevation Model with spatial resolution of 30 m. In order to determine the relationship between geomorphic characteristics and sediment yield of the subwatersheds, a multivariate regression stepwise analysis was used. In the multivariate regression, the important geomorphic characteristics which affected watershed sedimentation were identified and based on those parameters, the best annual sediment yield and geomorphic characteristics equation were presented.
3- Results
The subwatershed areas under study vary from 40 square kilometers for the Chakaneh Olya to 9339 square kilometers for the Hossein Abad subwatershed. The average annual sediment yield for the studied subwatersheds during the period of 30 years varied from 1026 tons per year in the Jang subwatershed to 274572 tons per year at Hossein Abad watershed. The subwatersheds of Kalateh Rahman and Jang had the highest and lowest sediment yield, respectively, with 317 and 5 tons per square kilometers. The relationship between geomorphic characteristics and sediment yield of subwatersheds showed that the annual sediment yield had a positive correlation at the 5% confidence level with form factor and annual rainfall. The results of this study showed that the watershed shape parameters including form factor, elongation ratio and shape index had high correlations with sediment yield with the pertaining coefficients of 76.8, 76.5 and 72 percent, respectively. Also, the correlation coefficient of annual rainfall with annual sediment yield was 73.9 percent. After rainfall and form factor, elongation ratio was the third parameter that had a high correlation coefficient (76%) with sediment yield. In addition, watershed shape index which was a function of form factor was correlated with sediment yield at 72%.  Among these characteristics, the annual rainfall and watershed form factor were used in the stepwise regression in the final model and were selected as predictor variables for sediment yield. Study results showed that the annual rainfall and watershed form factor variables could predict 64% of the annual sediment yield of the studied watersheds.
4- Discussion & Conclusions
The results of this study indicated that there was a significant relationship between the geomorphic characteristics of the studied watersheds and annual sediment yield. Watershed form factor was a dimensionless index for flood flow and movement, erosion severity and sediment transport capacity of watersheds. This factor was a function of watershed area and length. The runoff and the amount of flood peak in bigger watersheds will increase the sediment yield. Many researches have reported a high correlation between rainfall and sediment yield. Arid climate and poor vegetation coverage in the selected watersheds were the main reasons for the high correlation of rainfall and sediment yield. Soil erosion and sediment yield would increase due to the high intensity and low duration of rainfall along with the scarcity of vegetation coverage and erodible soils in this region. Overall, the study results indicated that with the development of new technologies and the possibility of extracting different physiographic and geomorphic parameters of watersheds from a Digital Elevation Model, it is possible to present regional equations for the prediction of sediment yield using geomorphic characteristics that can be used in sediment control and Watershed Management Programs.

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Extended abstract
1- Introduction
Fluvial and aeolian processes are important factors in changing the surface of morphology in the Earth. When rivers and sand dunes meet, the transportation of sediment  between them can lead to one of the systems or both  of them change. With their connection between river sediment and wind systems there would be lots of reactions, but very little has been studied. According to the previous studies in Iran, river and wind systems have been studied separately. Whereas ground-level processes rarely interact with each other, there is so many important proofs that river and wind processes simultaneously are interacting. The interaction between these two processes is important for mantaining the purposes of an intergrated management of fluvial and aeolian systems, considering the wide vastness of Iran’s effect by wind and river erosion. This research is the first inventory of interactions between rivers and sand dunes with the aim of systematically analyzing of the interactions between fluvial and aeolian geomorphology and determining the dominance of Fluvial and aeolian systems in different environments.
2- Methodology
The method of this research is descriptive-analytical. This study is a visual search of  the interactions between rivers and sand dunes using satellite imagery hosted by Google Earth (GE) as well as Landsat 8 (USGS) images in the arid and semi-arid regions of Iran. Using these images, surface and landforms from fluvial and aeolian processes can be identified. Because of this reason, this study focuses on the interactions between sand dunes and rivers, where the characteristics of both are easily reconized. To intensify this research, library resources including books and articles have also been used. The search of methodology started at the margins of dryland areas visually identified within Google Earth. Than Identifiable river courses were (bieng  traced up and down the streams to find places where aeolian dunes interact with river courses. Interactions were identified at a regional scale. In this research, 304 sites, where rivers and sand dunes met, are identified and analyzed  by using imagery satellites for the first time in the country. The classification scheme of Liu and Coulthard (2015) has been used to classify the types of interactions between the sand dunes and rivers. At each site a key word   has been used to classify the types of interactions between the sand dunes and rivers. At each site key attributes such as river direction, sand transport direction, fluvial aeolian meeting angle, sand dune type, and river channel pattern were identified and their relationships between each factor was investigated. Based on the data, six different types of interactions between rivers and sand dunes were classified, that reflected changes between the fluvial and aeolian systems.
3- Results
According to the data from 304 sites in arid and semi-arid regions of the country, although longitudinal sand dunes are most occurring among all the sand dunes, a similar distribution of channel patterns can be observed for each level . Braided channel patterns have the highest frequency and straight channel patterns and others have the lowest frequency. In all of different channel patterns, the most frequent interaction is fully fluvial dominant and the  lessfrequent  one which is the type of mostly aeolian dominant and balanced. In braided channel patterns, the frequency of interactions from types of mostly aeolian dominant and balanced more than other patterns. In balanced conditions, rivers and dunes connect more in the angles of 45 to 90 degrees
4- Discussion & Conclusions
Four variables changes has been analyzed to seek possible relationships between fluvial and aeolian systems, including dune type, channel pattern, meeting angle and the interaction. The results showed that there is a significant relationship between the type of meeting angle and the type of sand dune, the meeting angle and the type of interaction, the channel pattern and type of interaction. These relationships have shown that active river channel patterns are most common where aeolian or fluvial systems are dominated, but the balance between them is not sustainable. There was also no relationship between sand dunes and channel patterns. The results of this study are in line with Liu and Coulthard (2015) studies that show significant relationships between fluvial and aeolian processes. The results of a survey of 304 distributed sites in the arid and semi-arid regions of Iran showed an extensive interaction between rivers and sand dunes. According to the results, it can be said that in many sites, wind and river processes have a significant impact on each other and then on the landforms and geomorphology of the site. Nevertheless, more research is required to investigate how each fluvial and aeolian processes affect each other, as well as geomorphologic changes caused by them in Iran.

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Extended abstract
1- Introduction
The Hedijan coastal plain around the Zohreh River is a hub for essential agriculture, fisheries, trade, and the military. Any change in the regime and territory of the Zohreh River will have significant economic, social, and security effects in the region. Due to the privation of the region and preserve the available resources and capital, it is necessary to carefully study the hydraulic parameters affecting the morphological changes and the complex pattern of the meandering of the Zohre River. In this study, considering the special conditions of this coastal plain, it has been tried to study geometric features such as curvature coefficient, curvature radius, central angle, and river arc length in three time periods by studying and examining satellite images in a GIS environment.
 
2- Methodology
In this study, to study the morphological changes and meandering pattern of the Zohre River in the coastal plain of Hindijan, Google Earth satellite images from 2000 and 2014 were used. Based on these two images, the old route of the Zohreh River can be identified in the study area. In the next step, to investigate the meandering and morphological changes of the river, the route drawn from Google Earth entered the GIS environment. Using the ArcMap 10.2 software, to examine essential parameters in river morphological changes, circles with a suitable radius tangent to the existing curves in the river path were drawn. In the old route, 35 meanders were detected, and in the 2000 and 2014 routes, 21 meanders were identified and examined.
 
3- Results 
In order to study the morphology and meandering pattern of the Zohre River in the study area, various parameters such as bending coefficient, central angle, arc length, half-wavelength, and radius of curvature were calculated. According to Wolfert (2001), four types of rivers, including direct, sinusoidal, meander, and more meander, have been introduced in terms of the degree of curvature of rivers. According to this criterion, the Zohre River can be placed in a meandering river in the study area. Also, the number of meander from previous years, 2000 and 2014, was 35, 21, and 21. The maximum radius of the meander of this river was 450.1, 661.8, and 632.3 m. The lengths of the arch were 1197, 1118.2, and 1154.6 m, respectively. There have been alternating positive and negative changes in the values of the central angles in all three study periods. The average central angle from the old route to 2000 has been declining, and from 2000 to 2014, it has been increasing. In the old route, based on the size of the central angles, 57.14% of the torsions are in the overdeveloped area, 14.30% of the torsions are in the developed inverted 11.42% are in the undeveloped area. 17.14% was the size of a cow's horn, and no percentage was found for quasi-twisting curves. In 2000, based on the size of central angles, 42.86% of turns were over-developed, 14.30% of the turns were over-developed, and 23.80% of the turns were twisted. The average amount of radius in the old path increased from 450.1 to 66.81, and from 2000 to 2014, it decreased to 632.3. In total, this parameter has increased over three time periods. Finally, the obtained values for this parameter indicate that the river is meandering and the morphological changes in these three periods.
 
4- Discussion & Conclusions
The results showed that significant changes have taken place and are taking place over the years under study. During the three times of periods, four significant shortcuts and other significant morphological changes occurred. It is predicted that in the place of the 18th meander at the location of the existing bottleneck, there will be a shortcut in the future, which will eliminate the existing meander and create new ones.
Also, according to the Wolfert classification criterion based on the bending coefficient (1.5-2) and the Corneiss classification based on the central angle (158-296), the Zohreh River is located in the Hindijan Plain is in the category of meandering and the meander is overdeveloped.

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1- Introduction
Changes in river pattern is one of the most important issues of river engineering that affects the activities and structures of the river bank. It is important to study the morphological changes of river channels in order to find appropriate control solutions to solve the dynamic problems of these areas. The morphology of the riverbed pattern over time is a function of various factors such as geological formations, flood discharge, changes caused by human factors, vegetation, topography and tectonic movements. Statistical studies of river patterns have presented the morphology of a number of geostatistical rules. In this regard, the sinusoidal pattern of the riverbed depends on the dominant role of processes and a set of factors that are applied over time. A hydraulic structure refers to a structure in which all or part of the body of water is in contact with water in a way that changes the natural flow of water. These structures are used for purposes such as transmission, energy dissipation and flow cessation. There are different types of hydraulic structures and their use depends on the type of water source and the purpose used. In any case, in general, stair is one of the most important hydraulic structures. The construction of bridges in the course of rivers causes changes in the morphological behavior of rivers.
2- Methodology
The two most important rivers in Gilan province are Plorud and Shalmanrud located in the east of Gilan. Data mining algorithm was used to model the effect of hydraulic structures. The algorithm determines the method used to search for the pattern in the data and is, in fact, like a mathematical procedure for solving a particular problem. Data mining algorithms refer to a set of inferences and calculations that provide a model of the data. In order to create a model, the algorithm first analyzes the presented data to search for specific types of patterns or trends. It then uses the results of this analysis several times to achieve the desired parameters to create a data mining model. In the next step, these parameters are used to extract accurate operational patterns and statistical processes in the entire data set. One of the most efficient algorithms used in the data mining process is the use of a priori algorithm. For modeling through a priori algorithm, six parameters of distance from bottom to bottom, cross-sectional area, full cross-section width, maximum full cross-sectional depth, average full cross-sectional depth and width-to-depth ratio were used. Another algorithm used to investigate the effect of constructed structures on the morphological behavior of measured rivers is Veca algorithm. The Weka algorithm consists of a set of methods such as categorization, clustering, and association rules and feature selection. In categorization, each data is assigned to a predefined class, but in clustering there is no information about the classes in the data. Therefore, considering the importance of investigating construction of hydraulic structures on riverbeds, modeling the effect of hydraulic structures on the morphological behavior of Shalmanrud River in Guilan province will be evaluated in this study.
3- Result
Of the 53 rules obtained, 12 were more attractive and accurate based on the data. Comparison of the rules obtained by using the a priori algorithm showed that among the six indicators measured in data mining operations, the indicators of maximum depth of section with average confidence of 92% and 25% of the participation rates in the extractive laws are in the first place; width to depth ratio with an average confidence of 88% and 24% participation rate in extractive laws is in the second rank; cross-sectional area index with an average confidence of 85%  and 21% participation rate in extraction laws is in the third place; full cross-sectional index with an average 79% confidence and 15% participation rate in extractive laws is in the fourth rank; average depth of full section with an average confidence of 77%  and 10% participation rate in extraction laws is in the fifth rank and downstream distance index with an average confidence of 75% 55 Percentage of participation in extraction laws is in the sixth place. Based on this algorithm, ten rules were extracted from the data set used. The first rule with an accuracy of 0.883 includes river morphology, width-to-depth ratio, cross-sectional area and maximum full cross-sectional depth. The second law with an accuracy of 0.867 includes river morphology, cross-sectional area, full cross-sectional width and distance from the downstream. The third rule with 0.769 accuracy includes river morphology, cross-sectional area, full cross-sectional width and maximum full cross-sectional depth. Based on the results obtained from the accuracy and usefulness of the indicators, the width-to-depth ratio index has the most beneficial mode in the extraction rules.
4- Discussion and Conclusion
In order to determine which of the two tested algorithms is more effective, the accuracy, sensitivity and specificity of the two algorithms used were measured along with the accuracy, sensitivity and specificity that can be used for each of the available algorithms. These indices were calculated to determine the accuracy of the classification for each of the categories. In fact, this criterion indicates the success rate of the classifier method in identifying samples related to each category. The call rate with the attribute, which is calculated as the a priori criterion for each of the available categories, shows the percentage of reliability of the output of the classifier method. In general, the results indicated the appropriateness of using the a priori data mining algorithm in modeling the impact of hydraulic structures on the bed of the two rivers Shalmanerood and Plerood because all three indicators of accuracy, sensitivity and specificity of this algorithm were higher than the Weka algorithm.