Environmental Erosion Research Journal

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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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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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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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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
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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1- Introduction
 The water flow that is higher than the river level and penetrates the surrounding lowlands is called flood. In urban environments, due to high human density and its economic importance, the occurrence of floods is important and can lead to a lot of human and financial losses. In the metropolis of Karaj, in the floods that occurred in 2018, in addition to the damage to urban infrastructure, 8 individuals were dead, 10 injured and 12 missing and this phenomenon damaged 40 vehicles as well. Karaj metropolis from a geomorphological point of view, according to the physical characteristics and form of waterways, is characterized by hydrological coefficients of sub-basins, high rock outcrop, and high intensity of storms. Due to the importance of preserving lands and gardens along rivers, and its agricultural status and existence of gardens within its basins, and most importantly, the establishment of Karaj metropolis at the river outlet from the mountains, conducting flood estimation and management and water storage in this basin is necessary.
Therefore, due to the importance of floods in urban issues, a lot of research has been done based on data from 1: 50000 topographic maps and 1: 100000 geological maps, lithology, digital land model, land use, aerial photographs, satellite images and Google Earth in order to obtain flood-prone areas. Therefore, in this study, the hydro-geomorphological features of Karaj metropolitan basins with emphasis on flooding are investigated by estimating and studying the physiographic characteristics of watersheds leading to Karaj metropolis and calculating the probability of floods in different time periods and spatial analysis. In order to manage possible floods, appropriate scenarios and locations should be identified according to the landform characteristics of the basin for storing and maintaining excessive water and floods.
2- Methodology
In this research, the research steps are as follows:
Required data collection:

• Preparation of remote sensing data including:
• Digital terrestrial model data (altitude, slope and waterway data),
• Landsat 8 OLI sensors (land cover data, vegetation density index and FCD index),
• Ground data preparation including:
• Karaj Municipality data (absorption wells, drainage canals and urban lands),
• Geological Survey (fault and lithology) data,
• Regional water organization data (hydrometry and groundwater),
• Meteorological organization data (climate data),
• Data from ground observations

3- Results
 The upstream basins of Karaj metropolis consist of 5 sub-basins named Klak and Hesar (in the east of Karaj metropolis), Azimiyeh, Taleghani, Siah Kalan and Delmbar (in the north of Karaj metropolis). The flow of surface water in the Klak and Hesar basins, which is directed to the Karaj River, and due to the construction of the Karaj Dam upstream of this river, practically possible floods in this basin are directed out of the urban environment by using the mentioned river. Therefore, there are no flood hazards in this basin. However, the northern basins of the city, due to the diversion of all surface water into the urban environment of Karaj metropolis, and the location of this city in its waterway bed, such as Taleghani Street, has faced high flood risks. Therefore, the northern basins of the city have been studied in detail. In Azimiyeh, Delmbar and Taleghani basins, protection measures including diversion canals and water storage ponds have been constructed to control floods, but due to lack of protection and proper management, they have lost their function.
Drainage networks located in the city of Karaj are transferred using two canals and a metro collector, which are located in the bed of the old streams of Kamalabad (Beheshti canal) and Hosseinabad (metro collector). These two old streams have irrigated the lands of Kamalabad and Hosseinabad using the water of Karaj River, so the slope of these canals is from east to west, which collects surface water from the city and through Haftjoye leads to the Shore River.
 The results of flood simulation in different return periods using HecRAS model show that in a 20-year return period, 0.27 cubic meters per second flood is produced in the largest waterway located in Azima, which affects 14 hectares of surrounding land. Also in Taleghani, Siah Kalan and Delmbar waterways, 0.3, 0.58 and 1.91 cubic meters per second of floods are produced, respectively, which affect the area equivalent to 15.82, 22.65, 85.51 hectares of the surrounding lands, respectively. In addition, by using the TOPSIS model and hierarchical weighting systems, the areas with flooding potential were identified. For this purpose, 9 criteria were used and normalized using fuzzy logic model and straight and inverse linear functions, and then using the AHP model, the effective weight of each of them was obtained. The results of zoning show that 56.8% of the area of ​​Karaj metropolis and its upstream basins are exposed to flooding and the potential for flood production, to the extent that north of Karaj and the slopes overlooking the city of Karaj due to he highest slope, height, rainfall and poor in terms of vegetation, are categorized with high and very high flood potential. On the other hand, the southern part of the city, due to the slight slope and rainfall compared to the northern part and the slopes overlooking the city of Karaj, and the density of gardens and vegetation and agricultural lands, has the lowest risk of flooding potential.
With the aim of flood management and by using 14 criteria and a combination of weight assessment (WASPAS) locations to store flood water were identified:  4 locations (end of North Taleghani Boulevard with water storage volume of 4620 meters³, northern part of Azimiyeh slope with 8400 meters³ of water storage, northern part of the Atomic energy street with a storage volume of 8400 cubic meters of water and the northern part of the Epsino Valley with a storage volume of 3000 meters³ of water. Assuming a depth of 2 meters in each of the proposed zones, a total of 20 thousand cubic meters of flood water is self-sufficient through which flood water can be managed. Location of deep and semi-deep well drilling site is another way of managing surface runoff and flood that was located using 10 criteria and MCE model and the result is the identification of 16 sites for construction and drilling of absorption wells. Another measure for surface runoff and flood management is to increase vegetation density. The result of examining the relationship between surface runoff and vegetation density percentage obtained from the FCD distance sensing algorithm, shows that zones with maximum runoff have lower vegetation density. 25% of the area has the most runoff, So, according to the cooficit correlation (%98) between runoff and vegetation density, increasing the area of ​​green space and vegetation density from 25% to 75% reduces the runoff to less than 25 mm which prevents the area from causing floods.
4- Discussion & Conclusions
The results show that despite the construction of transmission canals and absorption wells in the city of Karaj, in some northern streets such as Tarbiat Moallem Boulevard, Bouali Gharbi and Nawab Safavi Street located in District 8 of the municipality, as well as Goodarzi and Nedaye Shomali streets in the south, no measures have been taken to control the flood, and due to the impermeability level, heavy rainfall compared to the southern part of Karaj and a steep slope (more than 15%), there are conditions to increase runoff on the street. Also, despite the construction of Taleghani, Moazen and Delmbar canals, which direct the surface water from the Taleghani, Siah Kalan and Delmbar sub-basins to the Beheshti collector, due to the lack of transmission capacity of the artificial canals implanted in at the metropolitan area, excessive surface water enters urban streets and generates floods. In order to manage floods and surface runoff in the city of Karaj, the identification of suitable locations for digging absorption wells and water storage pools has been considred, according to which 16 suitable locations for drilling wells and 4 suitable locations for constructing artificial pools had been identified for storing a total of 36,800 cubic meters of water. Also, increasing the surface infrastructure and vegetation from 25% of its density to 75% will reduce the amount of surface runoff by 75%, which leads to flood management.
 

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1. Introduction

Rivers are dynamic geomorphological systems that continuously change due to various influencing parameters. Morphological changes in the river channel primarily involve adjustments in channel width, depth, slope, and river planform. The extent of lateral migration of the river channel depends on factors such as bank resistance to erosion, the duration and magnitude of flow, the curvature radius of the channel, and the flow capacity to transport sediments. Quantifying geomorphological changes in rivers with an emphasis on flood hydraulics requires detailed analysis and complex modeling of the dynamic interactions between water flow, sediment deposition, and riverbed alterations. Flood severity, characterized by high discharge, significant flow depth, and extreme flow velocities, can have substantial impacts on riverbed structures, including changes in depth, width, channel meanders, as well as sediment transport and deposition. The Sefidroud River is one of the largest rivers in Iran, directly and indirectly affecting the lives of a significant population. Throughout history, there has been a strong inclination to settle near this river, with numerous urban and rural settlements located along its course. The occurrence of frequent floods in the past and the river's tendency to alter its channel, especially in the lowland regions, make the delineation of floodplains and prediction of future river behavior essential aspects of this research. Therefore, identifying and quantifying the geomorphological changes of the Sefidroud River and investigating the relationship between these changes and flood severity during mid-term return periods are key objectives of this study.
2- Results 
In the present study, four indices were calculated and used to quantify the river's morphological changes: channel braiding index (B), channel sinuosity index (P), lateral migration rate, and channel stability. The study reaches showed minimal variation in terms of the braiding index, with the Yasaval reach having the highest value, which is 0.07 higher than the Astaneh reach, which had the lowest value. The lower braiding indices of the Gilvan and Astaneh reaches, compared to Yasaval, can be attributed to the higher severity of human activities in the riverbed and the presence of the Sefidroud Dam upstream of the Astaneh branch. Regarding the channel sinuosity index (P), there is an inverse relationship between flow severity and shear stress with the sinuosity index. Reaches with lower flow severity and reduced shear stress tend to have higher sinuosity. Concerning the lateral migration rate, the results showed that this index is strongly influenced by the morphology and topography of the riverbanks. In the Yasaval and Gilvan reaches, which flow through mountainous regions, the lateral migration rate is lower (1.3 and 1.93, respectively) due to the rougher and more restrictive topography. The equations related to channel stability and migration rate indicate an inverse relationship: as the channel's migration increases, its stability decreases, and vice versa. Flood severity, which is the product of flow velocity and depth, can lead to significant changes in the river channel, meanders, and sediment distribution. The results indicate that, contrary to expectations, in areas with higher flood severity during a 25-year return period, river channel changes are less pronounced. This phenomenon is related to factors such as channel depth and longitudinal slope. Deeper channels, where flood severity is greater, exhibit higher stability and therefore experience fewer changes. In contrast, wider and shallower sections of the river, with slower flow, tend to undergo more substantial alterations.
3- Discussion and Conclusion 
Numerous studies have been conducted on river morphology changes across various regions worldwide, employing a wide range of methods. In this study, several of these methods were used to quantify and examine the geomorphological changes in the selected study reaches. However, a key aspect of this research is the relationship between flood severity and geomorphological changes in rivers. Most studies in this field have focused on the impact of one or several extreme flood events on river channel changes, typically employing a before-and-after comparative approach. However, this research utilizes hydraulic modeling, based on validated 1:1000 maps and hydrometric data, to comprehensively examine the overall effect of flood severity on river morphology and channel changes. The results were then compared with geomorphological change maps, providing a broader perspective on the relationship between flood dynamics and river morphology.
The results indicate that the braiding index of the Yasaval stretch is higher than the other two due to lower human interference and the presence of sediment bars and multi-threaded flows. The sinuosity index in the Astaneh stretch was higher due to the floodplain morphology of the riverbanks, which also contributed to a higher lateral migration rate. In contrast, the Gilvan and Yasaval stretches, with their more confined banks, showed greater stability and lower sinuosity and lateral migration rates.The study also examined the relationship between the geomorphological indices of the river and flood severity during mid-term return periods. Contrary to expectations, in areas with higher flood severity, channel changes were less pronounced. This can be attributed to the influence of channel geometry and longitudinal slope. In deeper sections of the river, morphological changes are less likely, resulting in greater stability. Additionally, in steeper slopes, both base flow and flood flows exhibit higher velocities, leading to greater channel incision. Deeper channels are more capable of handling floods with shorter return periods, reducing the likelihood of overflow and the formation of new channels.
 

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1- Introduction
Tectonic and human activities, such as land-use changes and urbanization, have directly and indirectly impacted the geomorphic characteristics of landforms. These activities have influenced erosion and sedimentation rates, evaporation and transpiration processes, runoff patterns, river dynamics, and the frequency of mass movements. This study examines the effects of human and neotectonic activities on geomorphological dynamics of the Shour River and Eshtehard Plain. The research aims to (1) Assess geomorphological changes in landforms to identify potential negative consequences and regional instabilities and (2) to identify key factors driving these changes, evaluate their impacts, and determine the most significant contributors to environmental vulnerability. Temporal and spatial changes in landforms were analyzed using aerial photographs, maps, and satellite images, supplemented with field data and observations. The findings were derived by cross-referencing satellite data, fieldwork results, and previous studies. Information sources included documentary references, scholarly articles, library materials, satellite imagery, and geological maps. Field observations were conducted across different seasons to assess the region's response to tectonic and human influences.
2- Results
Human activities are a key driver of geomorphological changes in the Shour River system. Civil construction, road building along waterways and alluvial fans, and the establishment of factories and mines in the erodible formations of the Eshtehard Plain have increased erosion, sedimentation, and river channel displacement. Land uses, such as agricultural fields, abandoned lands, salt marshes, pastures, and urban areas, were identified through satellite imagery, land-use maps, and field observations. The region’s geology and neotectonic activities also significantly influence geomorphological changes. Rivers are sensitive to tectonic displacements, which can alter their longitudinal profiles and geomorphic characteristics. The longitudinal profile of the Shour River is generally concave but shows convexities and fractures in some sections, often coinciding with intersections of the river and fault lines. These features suggest variations in the riverbed’s erodibility or elevation due to fault displacements. Agricultural land in the region has declined due to water scarcity, while urban and industrial zones have expanded. Population growth, increased groundwater extraction, reduced rainfall, higher temperatures, and rising evaporation rates have intensified drought conditions. Many farmers have abandoned their land, leading to reduced agricultural activity. Geological maps and tectonic analyses, combined with comparisons of historical Google Earth imagery, reveal that changes in river slopes and tributary deviations are likely linked to the Eshtehard fault line and ongoing neotectonic activity.
3- Discussion & Conclusions
This study analyzed the impact of human and neotectonic activities on the Shour River basin and the Eshtehard Plain. Human activities, such as road construction, urban and rural development, industrial expansion, and waterway diversion, have disrupted erosion and sedimentation processes. Mining activities have caused significant land-use changes, contributing to water and soil pollution, environmental degradation, and sedimentation in floodplains.
Tectonic activities have reshaped landforms by altering river courses intersecting with fault lines, displacing alluvial fans, and redirecting river flows. Evidence from base-level changes, sequences of alluvial fans, and terraces in the region confirms the influence of neotectonic processes. The downstream sequence of alluvial fans near the Halghedar Heights suggests tectonic activity and shifts in base levels. Channel displacement over time is also linked to fault-induced changes and base-level variations.
In summary, human activities have had the greatest short-term impact on the Shour River and Eshtehard Plain, while neotectonic processes have played a dominant role in shaping the region’s long-term geomorphology.