Geomorphology
Gholam hassan jafari; zinab barati
Abstract
The analysis of some geological features and structures can be used to determine Quaternary developments. Analyzing the types of landslides, their density, and scale is the key to identify the evolution of landforms. Based on this, the current research was carried out with the aim of spatial analysis ...
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The analysis of some geological features and structures can be used to determine Quaternary developments. Analyzing the types of landslides, their density, and scale is the key to identify the evolution of landforms. Based on this, the current research was carried out with the aim of spatial analysis of landslides that occurred in different lithologies of Mo’alem-Kelayeh basin, a part of eastern Alamut basin, between the longitudes 50°26'00″ to 50°31'20″ and the latitude 36°22'00″ to 36°30'00″, based on topographical, geological conditions, vegetation, the condition of waterways, and the proximity of different rocks in the area. According to the results, the Karaj, Rute, Shamshek and Neogene and destructive sediments are the most erodible formations in the studied area, which are the most important factors involved in the occurrence of mass movements on a micro and macro scale under the Mo’alem-Kelayeh basin. The nonresistant lithology is more extensive in the geographical levels downstream of the rivers. In such areas, in addition to the loosening of the lithology in wide sections, the material and energy flowing in the river also increases, if due to the lower slope of the slopes, the effect of the river on movements of the slopes becomes more limited. In the terrestrial levels close to the ridge line, matter and energy are less and lithology is more resistant; But due to greater slope of the slopes and the involvement of physical weathering in the porosity of rocks, the effect of river on the occurrence of surface slope movements increases.
Hydrogeomorphology
Gholam Reza Maghami Moghim; Yasaman Harasany; sharbano Bynaeyan
Abstract
Today, soil erosion is one of the important problems in catchments, lakes behind the dam, various agricultural areas and natural resources, which also causes land degradation, reduced soil fertility and filling the reservoir of dams. Due to climatic conditions, the erosion process in Iran requires more ...
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Today, soil erosion is one of the important problems in catchments, lakes behind the dam, various agricultural areas and natural resources, which also causes land degradation, reduced soil fertility and filling the reservoir of dams. Due to climatic conditions, the erosion process in Iran requires more attention because in this country, soil formation occurs in the long run and its destruction in the short term. The best place to control soil erosion is catchments. It is necessary to pay attention to catchments in the erosion process, especially catchments whose rivers flow into lakes behind dams or play an important role in providing drinking water to a city or region. In this study, using the hydrophysical model (CSY), the sedimentation potential of Damghan River watershed in the southern slopes of Alborz was calculated. The results of this study showed that the Namakeh sub-basin has the highest and the Dibaj sub-basin has the lowest sedimentation potential. The Kalateh Rudbar basin is also in moderate conditions. Therefore, the Namakeh basin is more vulnerable to erosion and should be properly managed by implementing soil protection plans and proper management of the erosion process in this basin.
hydrogeology
amirsaeed Hoseini; saeid Hakimi Asiabar; Mojgan Salavati
Abstract
Abstract The goal of this study was to investigate the relationship between vegetation and soil erosion and changes to the hydro-geochemical properties of water. Soil erosion is closely related to the type of vegetation and land use, and can change water quality in a region. For this, the present study ...
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Abstract The goal of this study was to investigate the relationship between vegetation and soil erosion and changes to the hydro-geochemical properties of water. Soil erosion is closely related to the type of vegetation and land use, and can change water quality in a region. For this, the present study collected and analyzed 15 water samples from the permanent waterways of Pirbadush and Gashun of the Qolyan River in the Qalikuh region of Lorestan, Iran. According to studies, from higher parts of the highlands of the region down towards downstream areas, water quality is reduced with the reduction of vegetation and increase of soil erosion and progressive Quaternary sediments, and with the entry of more cations and anions from sediments to water, and increased electrical conductivity, the total dissolved solids and turbidity. Thus, greater levels of vegetation in the highlands of this region increase soil permeability and reduce soil erosion. In this region, the reduced vegetation depends on the type of bedrock, and in some areas excessive grazing, in addition to altitude changes, thus increasing pollutants such as nitrates. Increased nitrates in the regional water depend on anthropogenic (livestock grazing) and geo-genic (expanded oil shales and the erosion of Quaternary deposits) factors. As a consequence, the regional water quality is more influenced by environmental and geo-genic factors, with anthropogenic factors less contributing to it.
hydrogeology
Hadi Nayyeri; Mamand Salari; Zhila Chardawli
Abstract
The soil erosion issue and lands' degradation is one of the most important issues in natural sciences. Soil erosion is the predominant geomorphic process on many land surfaces. In order to assess the environmental and economic consequences of soil erosion, quantitative data are needed. In this research, ...
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The soil erosion issue and lands' degradation is one of the most important issues in natural sciences. Soil erosion is the predominant geomorphic process on many land surfaces. In order to assess the environmental and economic consequences of soil erosion, quantitative data are needed. In this research, soil erosion is studied with of morphometric parameters. For this aim, Gheshlagh river basin iin Kurdistan province, was studied. Areas with a rating of more than 2 that entered directly into the main river were plotted as sub-basins for morphometric calculations. These areas included 47 sub-basins. The number of 16 morphometric parameters were calculated to determine the morphometric conditions of the basin and were considered as the input layer. Then, the results of these parameters were aggregated by four multi-criteria decision models TOPSIS, VIKOR, SAW and CF. In all four, the northern sub-basins were classified as areas with low and very low susceptibility to erosion. These basins are often located in volcanic rocks. In a general view, according to all four models studied, the basins in the lithology of dark gray shale (Sanandaj shale). Their sensitivity to erosion have been classified from moderate to very high. the final results showed that the multi-criteria decision-making methods, by presenting a classification, divide the region into several classes in terms of the degree of erosion sensitivity, and the VIKOR method, due to the greater coefficient of variation, has more accurate than the others.
maryam bayatikhatibi
Abstract
1-IntroductionIn the drainage basins of arid and semi-arid areas where the ecosystem is not able to recover quickly, extreme care should be taken with land use. The hydrological effects of changes in land use are manifested in the form of changes in runoff depth, minimum flow, maximum flow, soil moisture, ...
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1-IntroductionIn the drainage basins of arid and semi-arid areas where the ecosystem is not able to recover quickly, extreme care should be taken with land use. The hydrological effects of changes in land use are manifested in the form of changes in runoff depth, minimum flow, maximum flow, soil moisture, and evapotranspiration. Increasing runoff production in a particular area, in addition to increasing the potential for flooding, has other effects. Due to the type of soil and the topographic and climatic characteristics, the hydrogeomorphological changes caused by human encroachment on slopes and land use changes have been significant in Ojan Chai area (from the sub-basins located on the eastern slopes of Sahand Mountain). Due to erosion in the slopes of Ojan Chay area, it seems that the changes in the amount of runoff are very significant due to land use changes in the area. The study area is one of the rangelands of the country and unfortunately, cultivation is done in an unprincipled manner in the slopes that are not suitable for cultivation. In the coming days, the turbulence of the slopes will be intensified, the amount of runoff will increase, and the number of destructive floods will increase. Often, the soil of the slopes is severely eroded by runoff due to the extreme cultivation in the rangelands.2-MethodologyTo simulate the effects of land use change in a region or watershed, there are many hydrological models, one of which is the L-THIA. This model is a way to evaluate the long-term hydrological effects in a basin by which relative changes that occurred due to a change of use in the runoff can be simulated.The above model is a good tool to help measure the potential effects of land use change on surface runoff. This model is based on the Curve Number (CN) method of the US Soil Conservation Organization (SCS). Expresses CN values range between 0-100, where high values are for urban uses and low values are for areas with high permeability, such as wetlands and pastures with high vegetation density. One of the benefits of L-THIA is that it does not require calibrating the model with real area data. Model calibration is performed automatically using various default CN combinations available in L-THIA GIS. In this paper, to use the L-THIA model, station precipitation was prepared and Landsat satellite images (TM and ETM sensors) and specialized L-THIA software and Arc Map were used. In addition, the probability of a pixel being placed in a particular class is calculated, then the probability of its placement in other classes is estimated and classified according to the maximum similarity (maximum probability) in one of the classes. The above process is expressed based on Equation 1. (Eq.1). Where P (X) is the probability of the presence of the class wᵢ in the image, / x) wᵢ P (probability of each pixel with the spectral characteristic x belonging to the class wᵢ and p (wᵢ / x) the probability of belonging of each pixel with the spectral characteristic x appearing in the image Class wᵢ and p (X) is the probability of the presence of a pixel with a spectral characteristic. The error matrix, kappa coefficient and overall accuracy are used to evaluate the classification accuracy of the images using Equation 2.(Eq. 2). Where OA is overall accuracy, N is the number of experimental pixels, Pii∑ is the sum of the elements of the original diameter of the error matrix.The kappa index is calculated from Equation 3.(Eq. 3). Where po correctly observed, pc shows the expected agreement. The error matrix shows the interference or conversion of uses to each other. Land use maps have been prepared for two periods (1988, 2018) as well as land use change maps. 3-Results and DiscussionIn this research, using THIA L- model, the type of soil was determined according to the available soil maps, prepared samples, soil reports of studies of other organizations and field experiences, soil hydrological group in the study area as the basis of the model used. In the prepared map, it is clear that the range of hydrological group A is observed in the southern and southwestern parts. The area related to hydrological group B is mostly scattered in the northern, northeastern, and central parts. Hydrological group C is spread around the flood plains in the central part of the basin, and finally hydrological group D, which is the largest part of the basin surrounding Ojan largely.According to the land use map of 1988, the largest area is related to rangeland use with an area of 544.6575181 square kilometers and the smallest area is related to water use equal to 0.189899975 square kilometers. According to the land use map of the year 2018, the largest area is related to agricultural use with an area of 510.5889519 square kilometers and the smallest area is related to road use equal to 0.5715 square kilometers. Examination of runoff depth maps for 1988 and 2018 shows that significant changes have been made in terms of quantity and location. Examining the height of runoffs and comparing two different periods in a specific use in relation to changing the rainfall parameter shows that a change in the rainfall parameter can significantly increase runoff in agricultural areas. This situation in relation to the range of the gardens is different, especially in recent years, showing a complex situation. In the case of pastures between 2018 and 1988, there is no significant difference in the height of runoff. Runoff depth in different land uses and rainfall shows that in areas with low rainfall, the highest runoff height is seen in lands under agricultural use. With increasing rainfall, pastures produce the most runoff and again with increasing rainfall, the highest runoff production is related to agricultural lands. In agricultural lands, the amount of runoff has increased in three decades and decreased in pastures.4-ConclusionThe results show that over the past three decades, many rangelands have been cultivated. The area of agricultural lands has increased from 368.4917957 square kilometers in 1988 to 510.5889519 square kilometers in 2018. The results of calculations in such lands show that the height and volume of runoff has doubled from 1988 to 2018. In fact, increasing the area of cultivated land and land use changes from pasture to agricultural land has increased the amount of runoff. The results of studies on soils located on slopes show that the hydrological group of soils in this area is impermeable and with maximum daily rainfall that has increased in recent years, they can produce high-volume deep surface runoff in a short time. These slopes were considered pastures in 1988 (about 90 square kilometers of pastures have been converted into agricultural land). This has caused row crops to produce more runoff in these areas. The results of the studies with the model used and the result of this research in the area of Ojan Chay basin show that the main reason for the increase in height and volume of runoff was land use changes.Keywords: Land use changes, Runoff, Erosion, Flood, L-THIA model, Ojan Chay basin5-ReferencesKhaligi, B., Mahdavi, M., Sagafiyan, B. (2005). Investigating the effect of land use change on flooding using NRCS model, Natural Resources of Iran,vol,58,No,4,p 41-58.Razvizadeh, S., Salajegehe, A., Khaligi, S., Gafari, M. (2014). Investigating the effect of land use change on flooding using, HEC-HMS model (case study: Taleghan watershed) Journal of Rangeland and Watershed Management, Vol. 66, No.3, pp 373-386.Sadati, H, Golami, S., Sharifi, F., Ayobzadeh, A. (2008). Investigating the effect of land use change on runoff, Journal of Rangeland and Watershed Management, Vol. 4. No. 3, pp 301-315.-Hentati, A., Akira Kawamura, Hideo Amaguchi, Yoshihiko Iseri. (2010).Evaluation of sedimentation vulnerability at small hillside reservoirs in the semi-arid region of Tunisia using the Self-Organizing Map, Geomorphology, No. 122, 56–64-Kakembo,V., W.W. Xanga, K. Rowntree.(2009).Topographic thresholds in gully development on the hillslopes of communal areas in Ngqushwa Local Municipality, Eastern Cape, South Africa, Geomorphology, No. 110.188–194-Khairulmaini Osman Salleh and Fatemeh Mousazadeh.(2011).Gully erosion in semiarid regions,Procedia Social and Behavioral Sciences No.19, 651–661.Vahidi, Mohammadjavad; Rasoul Mirabbasi Najafabadi; Mohsen Ahmadi. (2020). Analysis and ranking of soil erosion prevention methods using multi-criteria decision-making methods in rural areas of Darmian County, South Khorasan, Hydrogeomorphology, Vol. 6, No, 23.209-233.Yamani, Mojtaba, Hamid Ganjaeian; Lila Garoso; Mahnaz Javedan. (2020). Identification of susceptible areas for the development of agricultural lands based on parameters Hydro geomorphology (Case study: Sanandaj city), Hydrogeomorphology, Vol. 6, No, 23.1-20.
Morad Darabi; Hossin gharehdaghy; Masod Nejabat
Volume 5, Issue 14 , June 2018, , Pages 199-218
Abstract
IntroductionMan's undue interference, livestock overgrazing, soil texture disorganization, and change in the geometry of channels are the main factors which could destroy the hydrologic balance of the watershed in an ecosystem. The systematic imbalance in a watershed could destroy the earth crust and ...
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IntroductionMan's undue interference, livestock overgrazing, soil texture disorganization, and change in the geometry of channels are the main factors which could destroy the hydrologic balance of the watershed in an ecosystem. The systematic imbalance in a watershed could destroy the earth crust and increase flooding. It could also result in the erosion and soil sedimentation behind the reservoir dams and the destruction of the agricultural lands, roads, and villages. In addition, it could reduce the production ability of productive sources. Soil erosion is one of the environmental problems that threatens natural resources, agriculture, and the environment. The objective of the present study was to evaluate the biological, managerial, and constructional watershed projects and their effects on reducing erosion, sedimentation, and parameters of land protective cover. This study was conducted between 2001-2010 in the Khorrambid urban watershed from the Sivand dam in Fars province.Methodology A. Primary Collection MethodThe preliminary data for Khorambid urban watershed from Sivand dam was collected by the executive detailed reports (Natural Resources and Watershed Management Office of Fars Province, 2001).B. Estimating the parameters of land cover layer, erosion, and sedimentation before implementing the watershed projectsBefore implementing the watershed projects, the vegetation parameters, erosion, and sediment yields in the executive and detailed reports were used to evaluate the parameters.C. Estimating the parameters of land cover layer, erosion, and sedimentation after implementing the watershed projectsIn the first step, the vegetation classification mapping was prepared and the vegetation parameters were sampled in the paired plots. It must be mentioned that one of the most effective items in estimating the erosion and sedimentation is to know the land cover parameters. To determine the rates of erosion and sediment exited from the network, it was required to calculate the rate of erosion and sediment on the domain. It was also required to calculate the controlled sediments on the waterway or at the rear of structures. In the first step, the locations of all structures executed in the intended sub-basins were specified by GPS to determine the sediments trapped at the rear of the structures. Meanwhile, their types, structural materials, and location maps were prepared. In the second step, the waterway slope, overflow height, reservoir length, waterway width, reservoir volume, and sediment volume were respectively determined by preparing some special forms via clinometer and meter. In addition, to estimate the erosion and the sedimentation of the domain, the experimental model of MPSIAC, modified by ArcGIS10, was used. When the nine layers of the MPSIAC model were combined and overlapped, the homogeneous units map was prepared. Next, the scores of nine factors were estimated and calculated to extract the sedimentation degree of each homogeneous unit according to the following equation:Qs = /253 e0.036R (Equ.1)When the sedimentation map was prepared, the erosion rate was calculated by the Sedimentation Delivery Rate (SDR) equation in the level of homogeneous unit. Regarding the factor of the basin area ( based on square mile), the following equation was used to determine the percentage of SDR.Log SDR = 1.8768 – 0.14191 log(10A) (Equ.2)To evaluate the differences between sedimentation changes in the sub-basins for the pre and post watershed operations, the normality test and Paired T-test in SPSS software were used.DiscussionThe results indicated that the factors’ score of river erosion and surface erosion which were respectively 30.77 % and 30.51% had the most effects and the land cover factor, with 15.05%, had the least effect on reducing the sedimentations to 21.97%. Also, the area of sediment class of 75-100 was 1375 hectares, which was equivalent to 15.78% of the basin's area. Indeed, in terms of the spatial distribution, it was located in the basin outlet and changed to class 50-75. The sediment class of 50-75 was 7339 hectares, equivalent to 84.22% of the basin's area. It reduced to 28.09 % and changed to the lower class of 25-50. Since there was a significant change in the sedimentation of the sub-basins in 0.05 levels, the results of this study indicated that the watershed projects were efficient in reducing the sediments. To manage the water and soil resources, to raise the effectiveness of watershed operations in reducing erosion and sediments, and to raise the land cover layer in Khorrambid watershed, the combination of both biological and constructional programs and treatments undertaken in the basin should be applied.ConclusionWith regard to the findings of this study, before the watershed operation, the sedimentation degrees in two classes of 75-100 and 50-75 were respectively 15.78% and 84.22%. According to the sedimentation class map, the sedimentation degree of 75-100 was located in the basin outlet. Since the structural watershed operation has been extended more than biological watershed operation, the sediment class with the area of 1375 hectares experienced lower sediment degree and changed to 50-75 class after the watershed operation. The sediment class of 50-75 was 7339 hectares before the watershed operation; however, by implementing biological programs, 2447 hectares of that class changed to the lower class of 25-50. Therefore, 15.78% of class 75-100 before the watershed operation reduced to 0% after the watershed operation. In addition, 84.22% of class 50-75 was reduced to 71.91%. Regarding the equation of SDR based on the area factor, the rate of SDR for the basin was 33.03%. Thus, the sediment rates for pre and post watershed operations were respectively calculated as 23755 and 14390 tons, which indicated 39.42 % drops in the total sediments. The results of this study showed that the watershed operation, which was a combination of protective, managerial, and biological programs, was implemented well in the measures of domain and waterway (structural) in the basin. Consequently, the sedimentation mean in Khorambid watershed decreased to 39.42%. The findings of this study are in line with the findings of researchers such as Roghani (2012), Salmanpour (2013), Azami Rad (2013), and Agharazi (2016).
Manuchehr Farajzadeh; Ali Asghar Hodaei; Maryam Mollashahi; Neda Rajabi Rostam Abadi
Volume 4, Issue 11 , September 2017, , Pages 59-81
Abstract
Introduction
Soil erosion as one of the most important natural hazards of each country usually results in reduced fertility, crop reduction, and desertification, particularly in arid and semi-arid areas. Two-thirds of Iran is located in the arid and semi-arid areas and one of its climatic features is ...
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Introduction
Soil erosion as one of the most important natural hazards of each country usually results in reduced fertility, crop reduction, and desertification, particularly in arid and semi-arid areas. Two-thirds of Iran is located in the arid and semi-arid areas and one of its climatic features is flood. Consequently, soil erosion is one of its environmental problems. Nowadays, since soil is important for the life of products and is directly related to the balance of the ecosystem and the water cycle, its protection and fertility are two important factors that shouldn't be ignored. The purpose of this study was to compare the suspended sediment in two drainage basins of the Caspian Sea, with a humid climate, and central Iran, with an arid climate.
Methodology
For research surveys, pluviometersdata, sediment and discharge assessment, slope, topography with land use, and lithology were used. Maps were obtained from survey organization, geological survey and mineral exploration, and Natural Rescues of Iran. To this end, land use maps, based on the land use type, were classified into six categories including urban area, forests land, pasture land, agricultural land, swamp land, and arid land, without vegetation cover. In addition, the geological maps, based on the stone resistance and amount of sediment production, were classified into ten categories including the hardest stones, very hard stones, so hard stones, enough hard stones, mediocre stones, enough soft stones, partly soft stones, powder stones, loose stones, and so loose stones. Finally, the data was analyzed using the SPSS software.
Results and Discussion
The results indicated a high and significant correlation between the rainfall and sediment. There was also a direct and significant correlation between the rainfalls, discharge, and yearly sediment of the field. In addition, a fairly good model was achieved from the rainfall, discharge, and sediments variables.
Considering the distribution of the sediment in central Iran, the highest sediment volume was seen in the west of the basin at Shahrokh, Chamriz station. The lowest sediment volume, in contrast, was seen in its north and south. In the Caspian basin, the highest sediment volume was seen in Gharasou and Ran basin at Ghezaghli station. The second highest sediment volume was seen in Gharaghoni station at Sefidrood basin. The lowest sediment volume was seen in Talesh basin and in the southern stations of the Caspian Sea.
Ali Dastranj; Omid Asadin Nelivan; Sanaz Falah; Aboutaleb Salehnasab; Shirkou Jafari
Volume 2, Issue 4 , January 2017, , Pages 39-55
Abstract
Ali Dastranj[1]* Omid Asadi Nelivan[2] Sanaz Falah[3] Aboutaleb Salehnasab[4] Shirkou Jafari[5] Abstract Estimation of sedimentation and erosion without sediment statistics serves as one of the main issues of basins and requires the application of empirical approaches to utilize data for managing plans. ...
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Ali Dastranj[1]* Omid Asadi Nelivan[2] Sanaz Falah[3] Aboutaleb Salehnasab[4] Shirkou Jafari[5] Abstract Estimation of sedimentation and erosion without sediment statistics serves as one of the main issues of basins and requires the application of empirical approaches to utilize data for managing plans. EPM model is one of the empirical methods widely used in the study of watersheds all over country. The main objective of the present study is to evaluate the effect of geological formations on annual erosion and sedimentation using EPM model and GIS and the investigation of its efficiency in erosion and sediment studies. Rock formation erosion and entering of huge sediments to Taleghan reservoir clarify importance of investigation on how sediments are produced and transported. In respect to the above results, it is worthy to note that Zidasht basin is moderate in terms of erosions and sedimentation and its erosion coefficient is 0.69. In addition, classification of erosion intensity showed that this basin has two intense and moderate classes implying that considering sediment and erosion is essential in soil and water conservation projects. The highest and lowest erosion intensity coefficients are observed in Dint2 and D1 respectively mainly due to presence of formations Ngm, Q1g, and orchards in sub-basin Dint2 and resistant formations of Ekta and Ekv and suitable rangeland land use in D1. [1]- Ph.D Student; Watershed Management; University of Hormozgan (Corresponding author), Email:dastraj66@gmail.com. [2]- Ph.D Student; Watershed Management; University of Agriculture sciences and Natural Resource Gorgan. [3]- MSc Student of desertification, Department of Rangeland & Watershed Management Saravan University. [4]- PhD Student Forest Mnaagment, University of Tehran. [5]- Ph.D Student University of Tehran.
Ahmad Nohegar; Majid Khazaei; Rasoul Mahdavi Najafabadi; Abdolrasoul Telvari
Volume 3, Issue 8 , December 2016, , Pages 161-181
Abstract
Received: 2015.03.15 Accepted: 2016.10.15 Ahmad Nohegar[1]* Majid Khazaei[2] Rasoul Mahdavi Najafabadi[3] Abdolrasoul Telvari[4] Abstract River bank erosion is one of the major sources of sediment for many rivers around the world. The aim of this study was to identify erodible riches in Bashar river ...
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Received: 2015.03.15 Accepted: 2016.10.15 Ahmad Nohegar[1]* Majid Khazaei[2] Rasoul Mahdavi Najafabadi[3] Abdolrasoul Telvari[4] Abstract River bank erosion is one of the major sources of sediment for many rivers around the world. The aim of this study was to identify erodible riches in Bashar river because the role of this river's in development of Kohgiluyeh and Boyerahmad province. In this study, using Satellite imagery, aerial photos and field survey from 1975 to 2015, the riverbank migration patterns for period of 40 years were investigated. After creating database of recorded data Bashar river, bank lines in different years digitized. Then, by comparing successive changes in bank line position, patterns of erosion and accretion was determined. Due to dischargr and Geological factores effectes on river pattern, these factors were evaluated. The Result of for identify erodible riches in Bashar river using GPS and field surveys, verified. The area of bank erosion and accretion by comparing sequential changes in banklines position determined. For short-term analysis, the migration rate from one any image to the next image is estimated. For long-term analysis, the migration rates are based on the difference between the 1975 image as the reference, and subsequent images. The results indicate that the erosion– accretion patterns in the sub aerial and subaqueous areas of the beshar river have changed significantly since 1994. For the short-term analysis, the highest erosion and accretion amounts are 4.7 and 7 ha from 1975-1984 and 1984-1990, respectively. the lowest erosion and accretion amounts are 2.6 and 2.3 ha from 2008-2011, respectively. The highest rate of bank erosion in different reaches equal to 9.6 and 4.6 ha/y in reachs of fifth and second bserverd. Also rate of bank accretion in fifth and second reachs equal to 9.6 and 4.6 ha/y observerd. the lowest erosion and accretion rate in reach of seven equaled 11.7 and 6.4 ha/y accounted, respectively. The correlation coefficient the between erosion and discharge and annual discharge averagelly for the short-term analysis observed 0.54 and 0.44, respectively. [1]- Professor, Faculty of Environment, University of Tehran (Corresponding Autor), Emial:nohegar@ut.ac.ir. [2]- Ph.D Student Watershed Management Engineering, Hormozgan University. [3]- Assistant Professor, Department of Rangeland & Watershed Management, Hormozgan University. [4]- Science and Research Branch Islamic Azad University (Ahwaz Branch).
Maryam Bayati Khatibi; Fariba Karami
Volume 3, Issue 7 , October 2016, , Pages 87-106
Abstract
Maryam Bayati Khatibi[1]* Fariba Karami[2] Abstract slope susceptibility is very vary to water erosion in geographical regions and climatic conditions .In recent time, losses of soils by gully erosion is serious work on geomorphological, hydrological and man aspect. Delivery of losses slope is ...
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Maryam Bayati Khatibi[1]* Fariba Karami[2] Abstract slope susceptibility is very vary to water erosion in geographical regions and climatic conditions .In recent time, losses of soils by gully erosion is serious work on geomorphological, hydrological and man aspect. Delivery of losses slope is treated farmer lands. gullies -as one main erosion form- is made on steep slopes and on susceptible surface material to erosion in Atashbeig Catchment (located at 37° 00' to 37° 20' E and from 46° 45' to 47° 15' N). Runoff is delivered materials to foot slopes at short time. In this paper is analysis rate erosion and rate of soil lose at single of gully by use of quantitative methods. In first step ,is investigated condition of region for gully form by use of Hydrotermal index(HTK). Then is studied runoff property taking into movement time and rate of sediment that is delivery to river by single gully(Dg) .The results of these studies show that is vary of erosion rate at throughout of Atashbeig catcment.Erosion is very intensive in middle part of this catchment .HTK show that is favorabel land of stady area at 5 month for gully erosion. Also the results suggessted that rate erosion is high in all part of area . [1]- Professor in Gegraphic Research Group; University of Tabriz; (Corresponding author), Email:m5khatibi@yahoo.com [2]- Associte Professor in Gegraphic Research Group; University of Tabriz.
