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Fluvial forms are important subjects in geomorphology. With regards to energy in water flow, rivers can be considered as important morphogenetic factors. Rivers flow in different states on the earth surface. Overflowing of rivers causes geomorphologic features in bed, course and floodplain. The following items are studied in this research: 1) estimating maximum discharge in some sections of meanders, 2) forms of beds 3) forms of overflowed lands 4) features on the courses of river because of overflowing. Cutting, side erosion, and sedimentation after overflowing are most important problems which take place in meanders. Moreover of field studies and morphometries of channels in the laboratory aerial photos, geologic maps (S. 1:100000), topographic maps (S. 1:250000) of the studying region through software such as ArcView, AutoCAD and Excel which are used for pursuing these aims. The results have shown that most of the cutting activities and channel changes are related to large periodical floods.

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Every year, thousands of tons of soils become unavailable from gardens, pastures, and agricultural lands by different forms of erosion, accumulating in potentially sedimentary regions, leading to significant losses. To manage eroded regions and inhibit this phenomenon, it is necessary to identify areas under erosion or under deposit and estimate the amount of eroded soil, thereby appropriate protective actions for reducing or lowering the erosion process can be done, in addition to determining vulnerable and critical regions. So, it is required to get access to high accuracy and efficiency. For this purpose, the experimental model has been used. This model has been used in different geographical environments in Iran. It has presented acceptable and satisfying results than other experimental models due to its quantifiablity and use of several parameters. 26 English Abstracts In this method, nine environmental factors have been investigated: geology, soil, climate, running water, gradient, earth covering, land use, surface and river erosion. Then, the rate of erosion and deposit is calculated by quantitative pricing of parameters. In this study, all data from these model data were estimated by the documentary method for evaluating deposit and erosion in Bekr Abad Drainage Basin, field studies were extracted and its required layers were provided in GIS Software. When databases were found, quantitative pricing and weight-giving to any of layers were extracted based on defined standards in the model, as well as in the final map of erosion spreading and the basin deposits. Comparing the amounts of estimated deposits and maps from areas sensitive to basin erosion with observational amounts and with field states of the basin indicates that fortunately, this basin is not in an acute state in terms of erosion values, and the development process is preventable by proper management. Also, surface erosion state gradient, and soil characteristic factors are most influential factors on the incidence of different erosion among different erosion factors of the basin.

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The increase of soil erosion as a threat to human welfare and even for his/her life is considered in this study. Soil erosion protection from erosion to develop methods for sustainable management of watersheds is necessary. Due to the absence or lack of data on soil erosion and sediment yield of watersheds in many countries, the use of new technologies is necessary. The aim of this study was the application of calibrated Russell model parameters using geographical information systems and remote sensing to identify areas within the Sykhvran watershed. Results  indicate that that there are more risks of erosion in the area. After creating a regression equation in hydrometric stations, rainfall erosivity factor (R) was calculated and interpolated. Soil erosion (K) was estimated to use the data. Soil and land surveying in the field were then carried out. Factor vegetation index using NDVI and length of shelves also were calculated through digital elevation model. Due to the lack of security operations in the watershed, we considered a factor equal protection operation. Based on the results obtained, the highest average annual erosion in Sykhoran catchment area was seen in the southern regions. The results of the correlation calculation of soil erosion and RUSEL model factors indicated significant correlation (R² =% 82) with soil erosion. The results also matched with one of the region's solidarity sediment stations with %82.7. The application of GIS and RS technologies for quantitative estimation of quantities have finally proved soil erosion in the area under study.

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Khoor and Biabanak area is located in centeral Iran, amongst areas that is in soil erosion and in spite of lack of runoff in area, observe several gully erosion in area. This structure is the most complex erosion structures that have evolution and growth during some steps and during the time. Natural processes and human factors have efective role in this case, but active tectonic as a most important factor in generating the part of gullies have basic role, but in neither inner nor foreign surces don’t attend to this factor in developing this phenomena.By investigating in this research can offer need full documentation on effect of active tectonic in generating gullies and introduce this factor as one of the factors in generating the turbulent and unbalance forms in this area. The main goal in this research is introduce the active tectonic factor as main factor in generating the Ordib gullies and affirmation on gullies genesis Variety in area of study. Analyse the climate data and geo field measuring of gullies dimensions in analytical wayes format, hydrothermal coefficient and WS coefficient shows that gullies generator processes in Khoor, Bayazeh and Ordib area have not climatic origin and more result of local base level changes and water base level for rupture the lake in Bayazeh and over flow and finaly for active tectonic changes in Ordib area.

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Determine the relative susceptibility of land to wind erosion and its effective factors in order to prioritize and soil conservation management and controlling their effective agents is necessary. In this research IRIFER 1 model had used for determine the potential for wind- generated sediments in the study area, in Ablolkhan region lands. In this study, the model was used IRIFR 1 . 9 defined effective agents investigated and the grades of each part in the area calculated and year-sediment production estimated. The results of current study in investigated region had shown 290.35 ha of 10.21 percent of the total area in the class, 424.7 ha of 14.93 percent in the middle class, 1516.16 ha of 53.34 percent in the class and 611.57 ha of 21.51 percent of the entire region too much in terms of production and the erosion of the wind. Generally, average wind erosion intensity in study area with 79 .55 points, and the average annual sediment production potential in this region with 3302.64 tons per square kilometer per year, had the high (intense) grade of quality. In the effective factors in the erosion of wind speed and operating IRIFR approach, as well as the situation in the context of the soil and the level of the most important factors in the wind erosion and has the potential to produce the sediment studied in the region. Wind factor, wind situation, soil texture and its surface cover were the important effective factor in wind erosion and sediment production potential in the study area between effective factors in wind erosion by IRIFR model

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The most countries Particularly in countries with climate arid and semi-arid, Soil erosion is a very important problem.Such research mentioned can be conducted empirical models for estimating soil erosion rates.compatible models for estimating water erosion in arid and semi-arid regions in the model is MPSIAC. The model demonstrates Is the potential for water erosionSediment In case of the Most Arid and semi-arid Are located also influenced by wind erosion.Study area is located, which coordinates 31 degrees 15 minutes to 32 degrees 7 minutes north latitude and 48 ° 17 'to 49 ° 20' east longitude. he average annual rainfall of 300 mm and the temperature is 24 degrees.In this study Methods Based on computational analytical method And field-based studies for this mean first The base were analyzed map data from hydrometery stations and sedimentation, meteorology and rain gauge, aerial and satellite images. In the next step the action of Geomorphological separate types then we need Preparing maps variables empirical models of water erosion and wind in GIS and the units in each of Factors has been analyzed influencing soil erosion. Finally, water and wind erosion rates were calculated for each type of geomorphology. After that, Amount of water and wind erosion potential Of each type Geomorphology were determined According empirical models The results showed that Catchment karoon in Types geomorphology Plain Apandaz, erosional plains and Clay plains Have Respectively 27.7, 35.4 and 36.7 Percent Potential sediment Portion. While determination Wind erosion in this basin Using the irifer model Is showed Plain Apandaz With an equal share of 72.7% The maximum amount of The playa with 15.4 percent and have least erosion basin erosional plains with 4.2% . in the dez basin was water Erosion Potential Portionin the cover plain and playa Over of 37% and Plain Apandazh %24.Geomorphological types The playa, Apandazh and covered respectively 47, 34.8 and 18.1% in regarding potential wind erosion are included.In bahmanshir basin water Erosion Potential Plain aPandazh With 48.2% and unit were cover plain and playa Respectively 34.2% , 17.5%. The maximum surface area of wind erosion in the Plain Apandazh equal to %19 and minimum deposit types include %3.3 belong to types covered Plain.

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Gully erosion is one of the erosive processes that mostly contribute to shape the earth surface. The development of gullies causes the loss of a great amount of soil and can be considered as one of the principal causes of geo- environmental degradation in eastern shores of Urmia Lake. The aim of this study is to evaluate the factors influencing on dynamic of area Gullies in a time period one year. For this purpose, in this research was used amount of Electrical conductivity (EC), Sodium Adsorption Ratio (SAR), PH of soil type, morphometric for classification and analysis of affecting factors in creating Gully erosion and climatology index , humidity index in regional formations for analysis of creating potential of Gully. Analysis of texture selective samples indicated fine particles of geological formations because of the weak structure of Aggregates have provided Suitable conditions for Longitudinal and latitudinal development of Gully. So that morphometric monitoring results of area Gullies is indicator high dynamic and growth rate area Gullies. The high concentration of soluble salts In particular, high levels (EC and SAR) have caused dissolution erosion and Piping erosion. Results indicated that creating of Gully erosion in area is impressed from two factors: 1. Climatic factors that create runoff and change in permeability rate 2. Physical and chemical characteristics of area soil.

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The estimated surface area affected by human-induced soil degradation is 24 percent of the inhabited land areas. A major impact of desertification is loss of biodiversity and loss of capacity of land is known as desertification. Desertifications permanently, but not exclusively occur in arid regions. Mazhan district of Birjand city have agriculture and livestock activities, including areas affected by severe wind erosion in the South Khorasan province. Average annual rainfall in the district during a 20 year period equal to 154 mm and are generally dry and desert climate. The aim of this study was to investigate the variability of wind erosion zones specified period using Landsat satellite images. Wind erosion models are used for a variety of purposes including estimating consequences of wind erosion, as well as for designing erosion control measures. For applying wind erosion model, one has to clearly define the objective of assessment and also to check if required data for running the model is available. In this paper, combining data from two models: the model of wind erosion IRIFR zoning and land use land cover classification using satellite images is done. Finally, multivariate statistical method of principal component analysis, the spatial and temporal variability of wind erosion zone is studied. The results indicate the highest rate of occurrence of wind erosion in areas of moderate intensity on the geomorphologically alluvial fans. The first principal component, which contains 98.89% of the variation in the areas of wind erosion is the best representative of the area during the period under consideration.

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Soil erosion is a natural process that has become a major global environmental threat as a result of human activities such as irrational land conversion and vegetation degradation. The purpose of this research is to model spatial distribution of likely soil erosion by water in Gharesoo watershed, assess the impacts of land use and slope on erosion rate, and identify soil erosion hotspots and prioritize them. For prioritization, the affected land patches with the highest potential and the effects of landuse and slope were studied. The Revised Universal Soil Loss Equation (RUSLE) was used in conjunction with Geographic Information system (GIS) to model soil erosion. The average soil erosion in the watershed was 18.65 t ha^-1 yr^-1. The slight, moderate and severe erosion classes encompass 62%, 26% and 12% of the watershed, respectively. Assessing the impacts of land use and slope confirms importance of interaction between these factors in increasing soil erosion, especially in agricultural areas with steep slopes. Zonal land suitability was used to delineate 15 patches as hotspots of soil erosion based on the RUSLE outcome. The results of this research reveals location and priority of land patches for implementation of mitigation measures such as terracing and vegetation rehabilitation, along with land use planning to reduce erosion and prevent it's negative impacts on environment and economy. 

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Potential of soils for wind erosion related to various agents such as particle size distribution of surface texture, surface moisture, and wind velocity. Two objectives investigated in this research: 1) Relation of dust concentration with surface moisture and particle size distribution of soil investigated in this research, using portable wind erosion simulator, and 2) Mineralogy of dust sources and arrival dust of Khuzestan province. These measurements had done at 10 moisture and 11 wind erosion talent’s regions. Field studies have shown increasing the threshold friction velocity and decreasing produced dust concentration with increasing moisture in surface soil (0-3 cm) from zero to 3%. However the dust concentration receives to zero, almost at 2.8% of moisture. Furthermore the soil of No. 6 region had the minimum, and on the opposite side, the soil No. 2 region had the most increase in threshold velocity. Also soil No.3 region in dry condition with 161.26 mg m^-3 had the most produced dust and soil No.2 in the same condition had the lowest dust emission with 101.23 mg m^-3 produced dust.  So, decrease rate of dust concentration’s changes for soil’s various regions were different, but at 2.2% of moisture decreased intensive and going to zero in all regions. Threshold fiction velocity increased more with surface moisture while more PM 100 was available in soil surface texture. Also, soil potential for erosion increased at dry condition while more PM 75 was available in soil surface texture. Mineralogy studies shows that most of dust consisting of Calcite and Quartz and based on the mineralogy of studied lands soil's could say these dusts have domestic sources.

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 This  investigation, have  hydropolitic significant for Aras River that have frequent and more lateral  migration.In this study is used many equation, for example, Ω ،Ự ω, وΈ …. Equation, for estimating of bank erosion and sediment dynamics .Output of  estimating  is analyzing and then maps is produced by using of GIS technique. The results of study suggested  that rate of channel changing is vary in  river course. Wide changes of river course is maximum  at near of Jolfa and Poldasht  ,in other parts is minimum .Wide changing of course is show that lateral migration is high and alluvium is thick and broad .Cut power of river is increased when radial of curves is more .This event is occurred  where that wide changes is high .The results also show that is increased rate of sediment when cut power is increased. Sadly  lateral  migration rate Iran orientation is increased at 30 decade recent. This result show that gradually is decreased area land of Iran . 

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Introduction

Geomorphology usually described as essential to the past, present and future prediction of nature's processes and estimate pace of environment changes. On both sides of Zanjan- Rud plains extended that covered with quaternaries alluvial sediments. The area appearance is a in a way that rivers on upstream of both sides should lead to higher elevation. But in parts of the southwest of Zanjan- Rud plains part front Mountain rivers water south of Zanjan parallel with the front part of the heights of the mountains leads to the Ghezel owzan. Rivers chaotic behavior resembles the appearance of the area so that Disneyland has created forms that look like they emphasized their dominance Neotectonic processes. Land forms created in another part of the basin are not similar to works of the old lake terraces.  Although at first sight this Landforms evidence of the activities area so that SATARI Neotectonic (2017) is known which formed the basis of the Neotectonic landforms and introduced analyze the indexes of the terms tectonically active basins has morphotectonic but Land forms is not the tectonic. the result end Although the possibility of tectonic activity is also According to faults in the area but the main factor in the formation of landforms function of changes in the Quaternary river to Neotectonic activities. Such conditions cause chaotic behavior quotation was Zanjans Talkheh- Rud does apply during the Quaternary.

Materials & Methods

First this chaotic behavior Study, the area Intended was determined from DEM 30 * 30 areas. For the past topography simulation was Digital Contour lines the equilibrium by Pixel to code software, and in different parts without equilibrium of Contour elevation lines, reconstituted on the basis of equilibrium line elevation. The phenomenon Direction captured of deviation and the river is now flowing in them was removed, in Table specifications latitude and longitude in Surfer software and specification X, y, Z reconstruction topographic, entered its output in software Global mapper and the spatial possible Rebuilding for past River Basin rivers. With longitudinal and transverse profiles and topographies of waterways in the direction of the current and was obtained previous simulations differences in altitude are and the rate of erosion. Referring to the field work and correct errors of interpretation and analysis was performed.

Discussion of Results & Conclusions

 Field studies indicate that evidence of deviation in bondage or topographic maps have been reflected as follows: 1- changes the direction at an angle of 90 degrees or greater along the rivers. 2- There are coarse-grained alluvial deposits in the river upstream, elementary and middle part is the source of the water, sediment and the final or the coastal route, sometimes in the midst of the water, and they are of record sediments. 3- A basin over time almost is stream symmetric .it means a left bank and right in time is equal and symmetrical. Tectonic may be due to disruption of such a situation; but when one side has no river stream a basin as a significant and insignificant area of study changed in the river. Stream Shorter towards the other side of the river indicate redirection of the river. 4-The heigh difference is inevitable in the coastal river basins; but when the difference in altitude along the channel length less and not diagenesis alluvial deposits in the river water sharing is indicative of a change to the track previous. 5-Contours with deep pulses or deep sinuses between a smooth contour and downstream to a simple sinus uniform lithology of a change of control over the area due to regressive erosion base level changes due to the redirection of the river.

With the changes of the base level of Ghezel owzan, retrogressive erosion dominant and shed on a river with very small area of basin along Zanjan- Rud to Ghezel owzan .and could be a part of divert northern slopes of the mountains south of Zanjan- Rud and lead to Gezel owzan. And create a new river that termed Talkhe Rud. A 110-square-kilometer alluvial fan testator chaotic behavior and alluvial plain series fans interlocking type which no upstream basin has any control on it. Shorter length of stream at one side of the river , the difference of high Elevation difference between river dividing line water on both sides  existence of  alluvial sediment not digenesis  in  Water dividing line, rivers 90 degrees direction change contours With deep pulses within and downstream of the smooth curve are simple sinus to a change of river courses.

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Forests located in the Zagros Mountains, as part of natural resources have different services. Soil retention is one of the most important services of forests. Population growth in recent decades has led to intensifying the exploitation of forests and uncontrolled destruction of them. Knowledge of ecosystem services as a new approach can help to prevent the destruction of forests. Current study was done by purpose of considering the role of forest ecosystems in soil retention as an ecosystem service and identification of areas with high supply of this service. InVEST software was used to model soil retention (SR), as the capacity of ecosystems to retain soil, by their equations. The results of the study showed that because of increasing the LS and R factors toward the south part of Lorestan province, the maximum potential of soil erosion was seen in the this region (1000 t/ha). The role of forests in soil retention was highlighted because spatial overlay of forest cover with maximum soil erosion areas was seen in the south part of Lorestan province. According to results the maximum of soil retention was allocated to forest cover compared to other land uses.

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ABSTRACT

Soil erosion and sediment production is including fundamental limitations in the useing of soil and water resources. The sediment yield of watersheds in addition to the loss of soil and soil fertility decline, caused reducing water quality. Therefore, evaluation processes that govern their behavior to better understand and explain the systems Watershed management practices is essential. The aim of this study is to estimate the total sedimentation determine of the basin. Studies obtained in the sub-basin of Saman 1, Vrkbar 1, four level 2 including R and R2 provides the same results in other sub-basins and the results have changed slightly. After calculating the data in tables results were compared with geomorphology. The results obtained by Hydro physical indicated that the basin Hryqan 2 with scaling potential 9.724 (including R2) in km2 highest and sub-basin four level 2 scaling potential 1.147 have been severity of erosion, but the way geomorphology sub-basin fence Tea 1 with producing potential 07 / 6 highest and sub-basin Hryqan 1 with producing potential 226/1147 least erosion was in the case study. The results obtained in the method Hydro physical indicated the index R2 be the better results than the R. comparing the two models showed that for determining erosion potential watershed geomorphology method is more suitable from method of Hydro physical.

Key word: hydro physical model, erosion, geomorphology model, sediment, saman watershed.

Introduction

Nearly 2 billion tons of resource soil   is destroyed and massive damage equivalent to 18.5 × 1012 Rails enter the country. Therefore to prevent this damage, it is needed adopt suitable management for preventing erosion and sediment movement. Soil erosion is one form of soil degradation. While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. Excessive (or accelerated) erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and (on natural landscapes) ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the eventual end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses. Water and wind erosion are the two primary causes of land degradation; combined, they are responsible for about 84% of the global extent of degraded land, making excessive erosion one of the most significant environmental problems world-wideSoil erosion is a naturally occurring process on all land. The agents of soil erosion are water and wind, each contributing a significant amount of soil loss each year. Soil erosion may be a slow process that continues relatively unnoticed, or it may occur at an alarming rate causing serious loss of topsoil. The loss of soil from farmland may be reflected in reduced crop production potential, lower surface water quality and damaged drainage networks  To archive to the aim the accurate data about the erosion in the watershed is necessary (intended, H. 1389: 18). Since soil erosion can be studied qualitatively and quantitatively, there are many models and more models for evaluation and were not giving much information about the erosion of soil. Specify a successful strategy to prevent erosion and reduce soil erosion depends on the mutual understanding between soil quality and erosion.

Material and methods 

In order to achieve the purpose of the research the case study be studied and identify based on the model of geomorphology and geo physical. In this study, to obtain the production of sediment and soil erosion the geomorphology and hydro physical models be used. In the research,   to prepare the database for estimation of sediment and erosion suitable map were produced, the including topography map, slop map, land use map, caver map,   the layer database in the environment GIS  software corrected and analysis.  In the research using hydro physical and geomorphology models was used to estimate erosion and sediment production. Many data were collected by field.

Result

According to the results of study in Table 11 by Hydro physical model -sub-basin Hryqan 2 with producing potential 9.724 (including R2) highest and sub-basin four level 2 sby producing potential 1.147 least severe erosion was, but in the geomorphology model sub-basin fence Tea 1 by producing potential 07/6 was the highest rate producing erosion and sediment in case study and    Hryqan 1 basin with producing potential 226/1147 be least erosion in the case study. The results of table 4 showed then the hydro physic model including R2 have better results than R, because the results obtained with R2 in the geomorphology model showed the   closer result. After calculating the data in tables results were compared with geomorphology. The results obtained by Hydro physical indicated that the basin Hryqan 2 with scaling potential 9.724 (including R2) in km2 highest and sub-basin four level 2 scaling potential 1.147 have been severity of erosion, but the way geomorphology sub-basin fence Tea 1 with producing potential 07 / 6 highest and sub-basin Hryqan 1 with producing potential 226/1147 least erosion was in the case study. The results obtained in the method Hydro physical indicated the index R2 be the better results than the R. comparing the two models showed that for determining erosion potential watershed geomorphology method is more suitable from method of Hydro physical.

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The growing population and the excessive and unconditional use of natural resources, especially in the soil, have caused many problems, most notably due to soil erosion and sediment production. To do this research, homogeneous unit maps were prepared using slope mapping, land use and geology maps. Each of the effective factors in erosion and parameters in the models were measured separately in each unit of operation, and finally, for each sub-area, the erosion and annual sediment production were calculated. Land use map was prepared using Landsat satellite ETM sensor images after classifying. Based on the results of this study, annual production sediment yield by MPSIAC method in the sub-basin of Unit A of the studied basin was 126.33 cubic meters per square kilometer, 6106 tons per hectare, in unit B sub-basin, respectively 74 cubic meters per cubic meter Kilometers square 167, 1804 t / ha and sub unit C were 150.36 m 3 / km, 9659 t / ha, respectively. The results of the comparison of erosion rates in determining the accuracy of the methods showed that the MPSIAC method is more suitable for estimating erosion and annual precipitation production in the natural and climatic conditions of the studied basin than the other two methods.

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Accurate understanding of geomorphological processes plays an impoortant role in the management of soil erosion. Soil erosion caused by the development of gully is one of the serious environmental problems that disturbs the balance of natural systems through the loss of water and soil. Dendrogeomorphology is one of the new techniques to determine the erosion based on the appreciation of the morphology and structure of the tree roots and stems and it is a suitable substitute to traditional methods. This method is appiable for parts of roots that have been exposed by erosion processes and are datable.After tree root exposure due to the gully erosion, suckers can develop. In this study, the estimation of gully erosion rate in Nilcooh (Galikesh) catchment was carried out based on dendrogeomorphological analysis of annual growth ring of suckers formed on roots. In this regard, a total of 23 samples from the roots of broadleaf trees, including Evangelical and wild persimmons, that  have been exposed after erosion, were dated. The minimum and maximum ages of roots were 3 and 18 years respectively. In this study, roots that their ages were from 2001 to 2016 were sampled during 2013-2016. During sampling, the information such as dimension of gully and geographical coordinates were also recorded. then Samples were dried in natural conditions and have been sanded for better clarity. Results of this study reveal that the rate of gully bed erosion increases as elevation and gradient of earth surface increases while the rate of lateral gully erosion decreases as elevation and gradient of earth surface increases. The average of annual volume erosion of gully is 0.043 m3 and the rate of the average of lateral and bed gully erosion are 0.153 and 0.036 meter respectively. 

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Erosion is a selective process. And some of the clay particles that are important in fertility transmitted into small aggregates. Gradual transfer of these particles, it results in larger particles with less fertility. Therefore, it is necessary to carry out research on fertility and granolometry. This research was done to objective determine soil fertility losses due to dry-farming erosion and sediment granolometry. At first, provinces were studied for dry-farming areas and production and were selected four areas. Required soil transferred to rain and erosion simulator laboratory. Characteristics such as Particle size distribution (PSD), Nitrogen, Available Potassium and absorbable Phosphorus was measured and were determined the amount of fertility losses due to erosion and sediment granolometry. Results showed that in pishkamar and kouhin the particle size distribution of sediment was smaller than the main soil, in Sararood closer to the main soil and in Gachsaran more than the main soil. Total nitrogen of the main soil of pishkamar, Sararood, Kuhin and Gachsaran was obtained 0.08, 0.1, 0.06 and 0.09%, respectively. absorbable Phosphorus and Available Potassium in the selected areas, were calculated 4.76, 104.5 and 4.47, 359.5 and 2.02, 222.4 and 9.62, 360 mg / kg, respectively.

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Soil erosion is a significant environmental issue of common concern in the world today.  Despite the importance of soil erosion in sustainable development goals in arid and semi-arid areas, the study of the geo-environmental conditions and factors influencing gully erosion occurrence is rarely undertaken. As effort to this challenge, themain objective of this study is to apply an integrated approach to detecting gully erosion features at the Sanganeh Kalat Basin.We also aimed to apply a Conditional Probability (CP) model for establishing the spatial relationship between gullies and the Geo-Environmental Factors (GEFs). The gully erosion inventory map field surveying was randomly partitioned into two subsets: part 1 that contains 70% was used in the training phase of the CP model; part 2 is a validation dataset (30%) for validation of the model and to confirm its accuracy. Prediction performances of the CP model Receiver Operating Characteristics (ROC) curve methods, respectively. In addition, the influence of all GEFs on gully erosion was evaluated by performing a sensitivity analysis model. The validation area under the ROC curve for the CP model were 87.32%, respectively. Also, based on sensitivity analysis, lithology, drainage density, distance from river and land use represent significantly effects on the gully erosion occurrence. This study has shown that the integrated framework can be successfully used for modeling gully erosion occurrence in a data-poor environment.

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Soil is the bedrock of life and economic and social activities, biological and biological diversity. Lack of statistics and information on soil erosion and sediment production in many catchments of the country necessitate the application of appropriate methods and models for estimating the severity of soil erosion and sedimentation. In this study, using the BLM Erosion Estimation Model and ElectRE-1 Multi-Criteria Decision Making Method, the erosion rate in the Romeshgan basin has been investigated and the erosion intensity and zoning map has been prepared. Results of applying ELECTRE-1 model show that topographic factor (slope) with weight of 0.5578 is more effective than other factors in basin erodibility and plays the main role. Also based on this model, sub-basin 1 in the north of the basin had the highest vulnerability to erosion and then sub-basin 2, 4 and 3, respectively. Using the BLM model, it was found that the low erosion class in the Romshgan catchment covers the most extent and then there are high, very high, moderate and minor erosional classes. In general, the area has moderate erodibility. The overlap of the layers indicated that the maximum erosion intensity was in the slopes and mountain units, which included new and old alluvial deposits and cone deposits, marl, lime, siltstone, sandstone, conglomerate and gypsum. Also, rainfed agriculture units have the highest intensity and forest and pasture units have the least amount of erosion. In terms of slope factor, lands with slope of 8 to 30 percent have the highest degree of erosion.
 

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Soil erosion is one of the important issues in the watersheds of Iran and can be considered as one of the most important barriers to achieving sustainable agriculture and natural resources. This study was conducted to compare the MPSYAK, EPM and BLM models using kappa statistical coefficient to assess soil erosion and sediment production in the Seymareh-e-Charnar catchment area. For this purpose, the position of 90 points of erosion points was determined in a field survey by a GPS device and these points were adapted to the final erosion maps.The evaluation of the results obtained from the models used by the Kappa statistical coefficient shows that the MPSYAK model with Kappa statistical coefficient is 0.91 compared to the APM and BLM models with a kappa statistical coefficient of 0.76 and 0.71 of greater accuracy In assessing the risk of erosion in the Seymareh Chenar catchment area. Also, the results of the overlaying of the final erosion map with erosion points showed that in the AP model, 81% of the points in the medium-risk zone, the BBL model had 37% of these points in the medium-risk zone and in the M-PSYAK model 90% of the specified points In the middle danger area.
Therefore, it can be said that the studied area is in the middle erosion class and the M-PSIAC model shows more accurate results for erosion evaluation in this basin. Based on the zoning done using the M-PSYAK model, 7.93, 14.45, 77.62% of the area of the area is located in very low, medium and low risk classes. Also, based on the APM model, 27.44%, 32.16%, 40.40% of the area of the area were in low, moderate, high risk classes, respectively. The results of this model estimated the coefficient of erosion intensity of 0.58 and the total sediment produced during one year was 1921183.6 cubic meters.