Iman Saleh; Majid Khazayi; Hamidreza Peyrowan; Behrouz Vaezi
Abstract
Soil erosion and sedimentation is one of the main problems in most of watersheds in Iran and a fundamental limitation against sustainable development. The usage of vegetation cover is the cheapest and most suitable approach for soil conservation. In the present study, the height, vegetation cover and ...
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Soil erosion and sedimentation is one of the main problems in most of watersheds in Iran and a fundamental limitation against sustainable development. The usage of vegetation cover is the cheapest and most suitable approach for soil conservation. In the present study, the height, vegetation cover and density of Vicia Dasicarpa and Villosa Vicia investigated on reducing runoff and sediment. The experiments conducted using standard plots with dimensions of 22×1.8 m, slope of nine percent and east direction; so that, nine experimental plots including three treatments and three replications installed and performed in the form of randomized complete block design. Runoff sampling was conducted from the tanks installed at the end of each plot, and the parameters of vegetation surface cover, vegetation density and plant height were measured at each sampling time. Then, the means of measured parameters were statistically analyzed and compared using Duncan Test. According to the results, the maximum runoff (97%) and sediment (94%) reduction were observed for Vicia Dasicarpa during the experiment. Also, it was detected that plant properties such as vegetation cover and density have a great correlation with runoff and sediment reduction which means soil and water conservation. Therefore, selecting the cultivar and plant species is an important step to increase the efficiency of this biological method. Based on the findings, in order to conserve soil and water as well as assisting the livelihood of the watershed residents, the use of legumes compatible with rainfed conditions having appropriate properties such as strong root, stem system and coverage along with initial irrigation at important growth stages of the plant in drought conditions is recommended.
Seyedeh Akram Jooybari; Hamidreza Peyrowan; Peyman Rezaee; Hamid Gholami
Abstract
Hendijan wind erosion center is located in Khuzestan Province and southwest of Iran. In the last decade, with the increase of erosion rate and concentration of important dust centers in this area, the study of heavy metal concentration and pollution in this area has become very important. For this purpose, ...
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Hendijan wind erosion center is located in Khuzestan Province and southwest of Iran. In the last decade, with the increase of erosion rate and concentration of important dust centers in this area, the study of heavy metal concentration and pollution in this area has become very important. For this purpose, 33 soil samples of this zone were collected based on land use change and with the aim of uniform distribution and analyzed by ICP-MSS. The obtained data show that the highest average concentrations of metals belong to Cd <As <Cu <Pb <Zn <Ni <Cr, respectively. Enrichment indices, geo-accumulation index and contaminant factor showed that the highest pollution in Hindijan area belongs to nickel, chromium, arsenic, cadmium and plumbum, respectively. On the other hand, ecological risk assessment in the mentioned area has shown that this region has a low ecological risk that among the studied metals, the highest ecological risk belongs to the two metals arsenic and cadmium. The results of PCA test showed that the metals nickel, zinc, copper and lead have both non-anthropogenic and anthropogenic sources and the source of arsenic and cadmium metals is human activities. According to the pattern of metal distribution, it can be stated that the activities related to Bahrkan fishing pier on the one hand and oil rigs off the coast of Hindijan oil field on the other hand have caused the concentration of nickel, lead, zinc and copper in the south of the study area. Agricultural activities have also controlled the concentration of cadmium and arsenic metals in this area, and the source of chromium concentration was determined as agricultural effluents, traffic pollution and residual pollution from the 8-year Iraq-Iran war.
Afshin Partovi; Hamidreza Peyrowan; Samad Shadfar; Fazel Iranmanesh
Abstract
Land cover change is one of the most effective factors of environmental change. So, understanding and predicting the causes, processes and consequences of land cover has become a major challenge. The remote sensing and satellite data technologies can be used effectively to detect and quantify land cover ...
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Land cover change is one of the most effective factors of environmental change. So, understanding and predicting the causes, processes and consequences of land cover has become a major challenge. The remote sensing and satellite data technologies can be used effectively to detect and quantify land cover changes and its effects on the environment. This research used the MODIS MCD12Q1 yearly data at 500 m resolution to evaluate the spatio-temporal changes in the national land cover of Iran from 2001 to 2015 in five years periods. Land cover maps of Iran were generated based on 12 classes for years of 2001, 2005, 2010 and 2015 and then evaluated using “Landcover Change Matrix”. Areal distribution analysis showed that the most parts of Iran covered by barren areas (more than 60%). The area of forests, croplands and grasslands were reduced from 0.8, 4.8 and 21.4 percent respectively in the year of 2001 to 0.6, 4.5 and 20.9 percent of Iran’s area in 2015. Furthermore, to evaluate land cover changes in five years’ period, the land cover map of the first and last years of each period were compared using “Landcover Change Matrix”. Results showed that in the five years periods of 2001-2005, 2005-2010 and 2010-2015 land cover of Iran changed increasingly as 2.13, 3.25 and 3.30 percent respectively of Iran’s area. And the overall changes of land cover in Iran from 2001 to 2015 is 6.08 percent of Iran’s area.
Sayed Naeim Emami; Hamidreza Peyrowan
Abstract
Marls are one of the main causes of sediment production and subsequent soil erosion in watersheds. Researchs shows that there is a close relationship between the rate of marls sediment yield and their physical and chemical characteristics. With the aim of determining the expansion of marly formations ...
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Marls are one of the main causes of sediment production and subsequent soil erosion in watersheds. Researchs shows that there is a close relationship between the rate of marls sediment yield and their physical and chemical characteristics. With the aim of determining the expansion of marly formations and a quantitative assessment of the mentioned indices role on the sediment yield of marls in Chaharmahal and Bakhtiari Province, a comprehensive study was conducted and its outstanding results are presented in this study. After identifying and separating the marly formations in Chaharmahal and Bakhtiari Province and performing systematic sampling, necessary physical and chemical experiments were performed and the results were analyzed using statistical methods. Then, using a rainfall simulator, the sediment production rate of each marly stratigraphic units was measured in the field. Results showed that about 1073.95 Km2 (equal to 6.5%) of province rocks has devoted to marly lithological units. On the basis of analyses, Razak, Pabdeh, Hormoz, Mishan and Gurpi formations with mean of 96.34, 94.41, 87.1, 76.17 and 33 grm-2 are the most sensitive marly formations, respectively. Sediment yield is directly related to silt amounts, total lime, active lime, exchangable sodium and reverse related to clay amounts. The presence of Kaolinite and Illite clay minerals is one of the intensifying factors in sedimen yeild in marly formations.
Amin Salehpour Jam; Hamid Reza Peyrowan; Mahmoud Reza Tabatabaei; Amir Sarreshtehdari; Jamal Mosaffaie
Abstract
The desertification process, by reducing the biological production potential, leads to the destruction of ecosystems. In this research, to assess the role of edaphic factors on desertification in rangelands surrounding Eshtehard, Halgh-e-Darreh highlands, first, the map of units was created by crossing ...
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The desertification process, by reducing the biological production potential, leads to the destruction of ecosystems. In this research, to assess the role of edaphic factors on desertification in rangelands surrounding Eshtehard, Halgh-e-Darreh highlands, first, the map of units was created by crossing maps of slope classes, land uses, and geology using ArcGIS 10.3 software. Three indices of erodibility, salinity and permeability for each land unit were considered and classified. 185 and 179 samples were taken during 2018 and 2019 for indices of salinity and permeability for zoning of the study area, respectively. Then, weights of indices and consistency ratio were calculated by the AHP method. Method of multicriteria optimization and compromise solution, VIKOR method was used to prioritize the alternatives. After calculating the weighted normalized values, priority was given to desertification potential of the units. Also, the results of AHP showed that from the experts' point of view, salinity is the most important factor in desertification. Other factors such as susceptibility to erosion and permeability coefficient are in the next rank order, respectively. The AHP-VIKOR model has very high degree of adaptation to the corresponding classes in the control map. The percentage of compliance and non-compliance of the classes of the potential of desertification risk were 92.91% and 7.09%, respectively. The range of changes of Vikor index based on AHP-VIKOR method varies from 0.443 to 0.967. Accordingly, the study area has three classes of potential or severity of desertification areally 0.5% moderate, 7.06% high and 92.43% very high class respectively.
Fazel Iranmanesh; Hamid Reza Peyrowan
Abstract
Tectonic activity affects the formation, deployment and evolution of landforms as well as erosion processes. The existence of several faults and anticline in the west of Khuzestan Plain has also led to changes in morphology and the establishment of landforms such as sand dunes. Therefore, the research ...
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Tectonic activity affects the formation, deployment and evolution of landforms as well as erosion processes. The existence of several faults and anticline in the west of Khuzestan Plain has also led to changes in morphology and the establishment of landforms such as sand dunes. Therefore, the research is aimed to determine the effect of tectonic activities on the morphology and behavior of sandy hills in west of Khuzestan Plain. To achieve the above goal, the following information layers were provided. The layers included Ahwaz geological map with a scale of 1: 100,000 and a topography of 1: 25000, field observations, as well as results from the processing of Landsat satellite images and IRS from 1991, 1998, 2002 and 2006. In addition, other GIS layers was used such as faults, anticlines and units, geomorphic units, sedimentary environments and drainage networks. Data analysis was also conducted based on field observations and geomorphic techniques and a comparison method. The results of geomorphologic indices such as coefficient of sinousity and integral hypersometry showed that the study area was strongly influenced by tectonic activity and morphotectonic units such as Hamidyeh-Ahwaz, Zeynol Abbas and Abol Gharib anticlines. However, other secondary factors such as the wind direction and the pattern of the flow of the Karkheh River, change the overall trend of sand dunes. It also causes sediment transfer from sand dunes to flood plains and dust production centers in the west of Khuzestan Plain. Therefore, the findings of this research can lead to the provision of necessary information for soil protection against wind erosion in the province, especially in the center of number one dust (Hooralazim), erosion and sediment sources along the Karkheh River Basin.
Alireza Habibi; Hamidreza Peyrowan
Abstract
The erosion rate ranking of geological formations can be a useful way for identifying and prioritizing the watershed sub-basins and it is important in view of decision making and management of the watersheds. Therefore, the present research was conducted with the aim of prioritizing the implementation ...
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The erosion rate ranking of geological formations can be a useful way for identifying and prioritizing the watershed sub-basins and it is important in view of decision making and management of the watersheds. Therefore, the present research was conducted with the aim of prioritizing the implementation of soil conservation operations in the Hablehrood sub-basins in northern Garmsar based on the degree of sensitivity of rock units to erosion. The method is based on the expert opinions and rainfall simulator experiment and comparison of the obtained results with erosion and sediment estimations of empirical models such as PSIAC, EPM and SWAT. Results showed that erosion rate ranking of the sub-basins based on the results of rainfall simulator conformed to the output of the three mentioned models in 12 sub-basins of 21 sub-basins and in other six sub-basins with two models, and in the remaining three sub-basins, it only conformed to one model output. Rainfall simulation results showed the highest correlation with the PSIAC model with a specific sediment yield of 9.2 t km-2 and based on the results of the observation data of the Bonkouh sediment-debit station, a special sediment of 8.02 t km-2 without considering the bedload, it became clear that the PSIAC model provided the most reliable estimate of sediment yield. Thus, matching the results of rainfall simulator in the erosion rate ranking of sub-basins with the PSIAC model shows that the rainfall simulator study on lithology units quite reliable with a 90% confidence level for erosion ranking classification of sub-basins and it can be used in similar basins.
Hamidreza Peyrowan; Mohammad Karimi Khaledi; Ziaeddin Shoaee; Ramin Sarikhani
Abstract
In this study, marls ofsouth of Hassan Abad and Varamin in Tehran Province, including the marls of Upper Red Formation unit M3 and Pliocene marls of unit Plm in slopes of five5, 20 and 40 percents were evaluated in terms of shape and intensity of erosion, physical, chemical, engineering and dispersion ...
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In this study, marls ofsouth of Hassan Abad and Varamin in Tehran Province, including the marls of Upper Red Formation unit M3 and Pliocene marls of unit Plm in slopes of five5, 20 and 40 percents were evaluated in terms of shape and intensity of erosion, physical, chemical, engineering and dispersion features. Accordingly, 20 samples were taken from mentioned marl formations. To achieve predetermined goals, granulometry, Atterberg limits, chemical analysis such as cations and anions, SAR, TDS, EC and double hydrometery and pinhole were tested. Results of double hydrometery tests on 18 samples indicated that only three have low dispersion degree Which are related to marls of unit M3 in undisturbed samples of station 1 with the form of gully erosion, station 2 with 40% slope and surface erosion and station 5 with 5% slope and channel erosion. According to the pinhole test, from 17 samples, 12 samples were classified as non dispersive and five samples as low to moderate dispersive classes. In this test, the majority of the samples with channel erosion and some samples with gully erosion showed low to moderate dispersion rate. Other erosion forms such as surface and rill erosion showed non-dispersive behavior. Based on chemical properties of the Total Dissolved Solids (TDS) and Sodium Percentage (PS), in Casagrande chemical graph, the majority of samples are clssified as dispersive soil, one sample with surface erosion in the boundary of dispersion and one sample with rill erosion as dispersive with the probability of 50%. In modified Sherard chemical method, all samples are classified as non dispersive soils. These results have no conformity with other physical and chemical methods so this classification is not acceptable. African chemical method showed better results compared to other chemical methods. In this method, half of the samples were classified as dispersive and the other half as non-dispersive. According to chemical and physicalstandards, dispersion phenomenon has been seen in all forms of surface, rill, gully and channel erosion. It has been concluded that marl soils are potentially dispersive under the influence of chemical and physical factors, even if they show surface and rill erosion forms, at the time of sampling. In other words, if the necessary conditions such as slope sleepness and runoff concentration occure in these soils, surface and rill erosion forms can be developed to dispersive forms such as channel and gully erosion types.
Kianush Behrahi; Gholamabbas Sayyad; Ahmad Landi; Hamidreza Peyrowan
Abstract
Study of effective factors on runoff quantity to achieve optimum measures for runoff controlling is an essential subject in watershed management. This study aimed to investigate the effects of land use type and land slope degree on runoff quantity using an artificial rainfall simulator in Kakasharaf ...
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Study of effective factors on runoff quantity to achieve optimum measures for runoff controlling is an essential subject in watershed management. This study aimed to investigate the effects of land use type and land slope degree on runoff quantity using an artificial rainfall simulator in Kakasharaf watershed from branches karkhe watershed (Lorestan Province). Based on the land use map, at 6 work units (sub basins), three land use types of pasture, forest and agriculture; and three land slope degrees of 10, 20 and 30 percent was chosen. In total 93 tests were run using an artificial rainfall simulator and the runoff quantities were collected and measured. Artificial rainfall simulator was a plexiglass non-pressure rainfall simulator with a plot size of 83.5 × 119 cm2 and height 160 cm. Statistical analysis was done using SAS software. Results showed that the average, minimum and maximum runoff quantity were 1499, 0, and 9100 cm3, respectively. Analysis of variance showed a significant difference (p<0.01) between sub basins and runoff quantity. Also, the interaction of sub-basins and land use showed a significant difference (p<0.01) on runoff quantity. There was a significant difference (at 1% level) between runoff quantity and the land slope so that by increasing the slope from 10 to 30 percent, the produced runoff volume increased. Besides, there was a significant difference (1% level) among runoff quantity of pasture, forest and agriculture. The volume of runoff in the forest regions was more than pasture and agriculture land use types.
Hamidreza Peyrowan; Mohsen Shariat Jafari; Dadvar Lotfollahzadeh
Abstract
The study performed to determine the relationship between landslide and increasing sediment load in Latian dam watershed. Sediment yield of six sub-basins were estimated with by two methods of MPSIAC and hydrometric station . More than 150 landslides were mapped by ETM+ and Google Earth image processing. ...
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The study performed to determine the relationship between landslide and increasing sediment load in Latian dam watershed. Sediment yield of six sub-basins were estimated with by two methods of MPSIAC and hydrometric station . More than 150 landslides were mapped by ETM+ and Google Earth image processing. Comparing the observed data with MPSIAC output in Lavasanat and Kond-Afjeh sub-catchments, it became clear that Lavasanat has less sediment yield. But, despite of this subject, observed sediment yield in Lavasanat hydrometric station is about two times in Kond–Afjeh, while the landslides area in Lavasanat and Kond–Afjeh sub-basins are 1.8 and 0.7 percent of the area. Based on the estimated sediment yield of MPSIAC model, the weighted average of specific sediment yield for Kond-Afjeh and Garmabdar sub–basins with landslide area of 0.7 and 2.4 percent are 387.02 and 431.39 m3km-2y-1 respectively, which means that increasing the relative percentage of landslide area from 0.7 to 2.4 percent, specific sediment yield increases by 11.5 percent. Based on data analysis in Roodak hydrometric station in Jajrood basin, average sediment discharge of the river in the first nine months of 1383 before Hajyabad landslide was 6.17 tons per day that increased to an average of 16.9 tons per day at nine months after landslide. This amount is equivalent to 170 percent increasing of sediment load in nine months after mentioned event. The interesting point is that this increasing of sediment yield was in the period of about 30% decrease in water debit . This means that not only increasing sediment yield of the river is not related to the water debit, but also, about 30% reduction of water debit is should reduce sediment yield. So, regarding to the area of 20.45 ha of Hajabad landslide zone, each hectare of landslide area could increase more than 8% of the sediment load in the river.
Hamidreza Peyrowan; Ali Jafari Ardekani; Mohsen Shariat Jafari
Abstract
This research has been done for the study of morphology of Ghezel Ouzan River from Ostoor to Manjil dams in two gorge and floodplain basins at 37 years period based on aerial photos, topographic maps and field surveying. The results showed the mean sinuosity ratios of, 1.46 and 1.22 for gorges and floodplain ...
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This research has been done for the study of morphology of Ghezel Ouzan River from Ostoor to Manjil dams in two gorge and floodplain basins at 37 years period based on aerial photos, topographic maps and field surveying. The results showed the mean sinuosity ratios of, 1.46 and 1.22 for gorges and floodplain basins so that they can be classified as meandering and sinuous river reaches respectively. More sinuosity at gorge basin is due to the geological and tectonically factors. In the other words, the river plan initiate and mature based on rock canal that originated from above mentioned geological factors. At floodplain basin in Pavehrood to manjil dam with 60 km length river reach, the river showed three obvious sinuous canaliform, sinuous point bar, sinuous braided and braided and anastomising plan . At period 37 years braiding extend in the boundary about 1.2 km widths in Hezarrood area. If the rate of widening of the river in this basin presumes in uniform rate, the velocity of the river widening is about 32 meters per year that is noticeable. Bank erosion with meandering form of the river in Haroonabad area through meandering growth and extensions of the loops occurred up to 850 meters at the mentioned periods. Based on central angel of meanders loops, 57.72 percents of loops are extended modes, 25.93 % very extended, 16.05 of others are new so the river has meandering hazard. Extension mode of the loop growth is the main mode with 56% frequency and based on water shear stress distribution, geometry of loops and relative radius of the loops, consequently accumulation point of the shear stress, the modes of translations, rotation, compounding and chute and neck cut off are observed. More than 75 % of canal shifting cases of the river is toward left bank so that the construction of any structures on the left bank of the river would be dangerous.
Reza Sokouti; Hamidreza Peyrowan; Davood Nikkami; Mohammadhossein Mahdian
Abstract
Considering to high distribution of the marly lands in west Azarbaijan province and high sediment yield of such lands, in this research, the relation among the form and the rate of erosion on marls with their erodibility properties were studied. So marly regions of province with the special properties ...
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Considering to high distribution of the marly lands in west Azarbaijan province and high sediment yield of such lands, in this research, the relation among the form and the rate of erosion on marls with their erodibility properties were studied. So marly regions of province with the special properties were recognized and soils were sampled. Soil erodibility indices were determined and analyzed by statistical methods considering the form and the rate of erosion. Also portable rain simulator were used to study of the runoff and sediment yield potential of such soils. Finally the factors affected the soil erodibility were determined by variance analysis. Results showed erosion rate could be classified as moderate. Gully erosion had highest number in Gara-agaj and Gara-tape areas whereas rill erosion had high number in all area of marlly lands. Surface runoff volume ranged between 255 to 577 cm3 in Shabanlu and surface runoff coefficient 0.23 to 0.53 in Gara-tapeh. Maximum yielded turbidity was 180 gr/lit in Gara-Agaj area. Clay ratio was the effective factor to gully form and Surface runoff volume also was the factor to form surface and rill erosion.
Manouchehr Amiri; Hamidreza Pyrowan; Ahmad Ahmadi Khalaj
Abstract
Since marls are highly sensitive to erosion and they annually sent thousands tons of fine grains sediments and clay to reservoirs of dam and artificial feeding stations and increase the cost of filtration of drinkable water and phytoremediation of artificial feeding water greatly, so the studies of different ...
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Since marls are highly sensitive to erosion and they annually sent thousands tons of fine grains sediments and clay to reservoirs of dam and artificial feeding stations and increase the cost of filtration of drinkable water and phytoremediation of artificial feeding water greatly, so the studies of different aspects of marls are important for experts and researchers. In this study we have tried to classifying them and recognizing effective variables of marls classification and examine the relationship between marls groups whit the types and erosional intensity of them. For this purpose, samples were taken from 41 points and they were sent to the laboratory to determine the values of the physical and chemical parameters. The characteristics of the location of the samples such as slope, geographical location and the privilege of seven parameters for soil surface factor and so on were noted. The test of artificial rain was done by kamphorst΄s rainfall simulator apparatus in the adjacent of mentioned points and samples were taken to measure the amount of runoff and sediment of them in the laboratory by simple methods. Furthermore, to identify the types of minerals presenting in the marls and diagnosis of their age, seven samples were analyzed by x-ray diffractometer and eight thin sections of marl and rocks collected along with them such as sandstone and limestones were provided and studied by polarizing microscope. Then, the abnormal data were normalized by logarithm and afterwards, all data were evaluated by cluster analysis, discriminant analysis and scalogram method. Results indicate that the marls are respectively divided into four (S1, S2, S3, S4), five (P1, P2, P3, P4, P5) and six (T1, T2, T3, T4, T5, T6) groups based on their chemical, physical variable and their combination. Fisher linear functions obtained from the classification predict the marl groups, respectively, with an accuracy of about 96.5, 83.9 and 96.9 percent in a correct way that the chemical variables are more appropriate for classification. This study shows that the marls containing a small amount of neutralizating material with high liquid limit are capable of higher erodibility.
Hamidreza Peyrowan; Ali Jafari Ardakani; Mohsen Shariat Jafari
Abstract
Downstream of Ghezel-ouzan River from Ostoor to Sefidrood dams with approximately 195 kilometers length studied in this research. For morphological study, the topographic maps and the aerial photos (1955 and 1992) on a scale of 1: 50000 are used. At the first step, the river plan was drawn in both gorge ...
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Downstream of Ghezel-ouzan River from Ostoor to Sefidrood dams with approximately 195 kilometers length studied in this research. For morphological study, the topographic maps and the aerial photos (1955 and 1992) on a scale of 1: 50000 are used. At the first step, the river plan was drawn in both gorge valley and flood plain basin and then geometrical characteristics such as width, wavelength and amplitude of meanders loops, sinuosity, radius and other factors of the meanders measured in two above-mentioned basins. This research showed that, the mean values of the central angle of meanders and sinuosity coefficient of the gorge river is 140.55 degree and 1.46 respectively. It is more than flood plain reach with 105.08 degree mean central angle and 1.22 sinuosity coefficients. Therefore, the river is more meandering in the mountainous reach. Lateral shifting of Ghezel-Ouzan River in flood plain reach showed that 63.3% and 26.6 % respectively occurred to left and right and 10.1 percent to both sides due to braiding. Lateral shifting of Ghezel-Ouzan River at flood plain reach indicates that lateral shifting of the river, occurred mainly toward the left bank, which is agreed to the direction of the tectonic stresses due to the plate tectonic movements. It proves that tectonic factors affect on river pattern even in the erosional reach. In gorge basin hydraulic bed-shear of the river is quantitatively 150 Pascal, whereas, shearing strength of volcanic rocks in gorge valley lies in the order 150 Mpa., i.e. one million times higher. Therefore, the erosional processes could not have formed the gorge valley. To prove this opinion, dip and direction of rock bank joints of the river in gorge basin recorded at field in 10 stations and about 439 joint surfaces. The centerline of the river channel drawn based on the topographic maps, and then, it changed to the series of broken and straight lines at the intervals of 250 m, and then their directions were determined. The rose diagram of rectifying river segments and rock joints of the gorge canal are similar with together. It shows that the river in mountainous basin had neotectonic predesigned pattern and the river current on the bedrock and only it partly can widening its valley.
Hamid Reza Peyrowan; Mohsen Shariat Jafari
Abstract
One of the most important problems that empirical model users in Iran are facing with, is that these models are prepared for countries with special conditions such as lithology factor, which scores are given based on geology condition of origin country that are not compatible for a vast country like ...
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One of the most important problems that empirical model users in Iran are facing with, is that these models are prepared for countries with special conditions such as lithology factor, which scores are given based on geology condition of origin country that are not compatible for a vast country like Iran with a great lithological variation. This research was conducted to reduce such problems and increase the efficiency and localization of these kind of models and provides rock erosion sensitivity factor for their special conditions. In PSIAC and EPM as a common experimental models, lithology factor is an important agent among other effective factors. In this research, a comprehensive classification of erodibility has been produced in 10 orders, based on mineralogy, chemistry, texture, structure and mechanical properties. Regarding to aridity of many parts of the country, and low rate of soil generation, erodibility rates of geological formations would be an important tasks. Results showed that, about 70 percent of the area covered with very low to low strength lithology to erosion and have a high potential of sediment yielding. Geological formations’ erodibility has been classified in30 Tamab watershed with order of 4 and the results are compared with EPM results and monitored values in river gauging stations. Results also indicated a good agreement with high confidence with natural conditions and with respect to other important factors of the watersheds such as topography and rainfall.
Hamid Reza Peyrowan; Amir Samadi Tabrizi; Samad Shadfar; Ahmad Motamed
Abstract
Marl formations are widespread in Iran. High potential to erodibility of marl formations in watershed basins of Iran cause many problems including loss of soil quality in agricultural and pasture lands and forests, increasing the risk of landslides and mass movements, reducing the quality of ground and ...
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Marl formations are widespread in Iran. High potential to erodibility of marl formations in watershed basins of Iran cause many problems including loss of soil quality in agricultural and pasture lands and forests, increasing the risk of landslides and mass movements, reducing the quality of ground and surface water, sediment load increases entered into the reservoirs, desertification areas due to intensive erosion and watershed management plan failure due to inadequate knowledge of the susceptibility to erosion the formations. The study area, Gatchab and Siahkooh Mountains situated in the northwest of central playa of Iran (Kavir plain). It is located in southwest of the Semnan city with 74 km distance. The widespread of the geological unit in the area is upper red formation with three members M1, M2 and M3. With respect to sedimentology finding on textures of Neogene sediments, they are sandy silt, silt, sandy mud and mud particles. The examination of distribution of various particle size of the sediments have shown that these sediments deposited in shallow water and lagoonal environments with changing of the depth, that changed to high dynamic environments condition of channel rivers. The results of analyses have shown that the percent abundance of lime in these sediments change from 24.28% to 34.98%. Because of the low contents of lime compound and clay particles, it is better to called them salty and gypsiferous siltstone and mudstone instead the marl term for these sediments.
Samad Shadfar; Ali Akbar davoodirad; Hamid Reza Peyrowan
Abstract
Gully erosion is a type of water erosion which causes degradation in both agricultural fields and rangelands as well in arid and semi-arid areas. According the role of soil degradation due to erosion, research objectives were to find out investigation causes gully erosion in Robat Tork Watershed. In ...
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Gully erosion is a type of water erosion which causes degradation in both agricultural fields and rangelands as well in arid and semi-arid areas. According the role of soil degradation due to erosion, research objectives were to find out investigation causes gully erosion in Robat Tork Watershed. In this research three representative gullies were selected in agriculture and rangeland working units. In each working unit, samples taken from nine soil profiles were analyzed for texture, organic matter, gypsum, total lime, pH, EC and SAR. Soil infiltration rate was measured where were drilled profiles in each working unit too, In addition, morphometric characteristics of gullies including length and lateral profiles, top and down width, depth of gully, the cross section, width to depth ratio, the slope of bed, gully length were studied. Results of the study showed that SAR and sodium cation are caused dispersion of soil particles and increasing gully erosion. percentage of clay and silt is 11% and 29% in surface layer representative head cut gully and organic matter is between 0.30% to 1.82% in agriculture unit. In rangeland unit, percentage of clay and sand is 41% and 43% in surface layer representative head cut gully and organic matter is between 0.29% to 0.99%.In rangeland unit, in a specified level, the number of gully is more than agriculture unit. Furthermore, the results showed that TNV in agriculture unit and pH, EC in rangeland unit is more than. In both units depth to wide ratio is more than 1 in every gully. Permeability of soil is 4.25 cm and 3.45 cm in agriculture and rangeland units respectively.
Ramin Salmasi; Hamid Reza Peyrowan
Abstract
The most of the soil erosion and sediment yield in the Talkheh Rood watershed are mainly related to marl formations. This study was conducted to evaluate physico- chemical properties of Talkheh Rood marl samples in rill, gully, mass and badland erosion types. For this purpose, marl samples were taken ...
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The most of the soil erosion and sediment yield in the Talkheh Rood watershed are mainly related to marl formations. This study was conducted to evaluate physico- chemical properties of Talkheh Rood marl samples in rill, gully, mass and badland erosion types. For this purpose, marl samples were taken from marl sediment of homogenous work units. Twenty four samples were selected, in total. Some of main physic - chemical properties of these marls were measured in lab. These properties were pH, EC, CEC, Lime, gypsum and OC content, SAR, Na, K, Cl, Ca, Mg, clay, silt and sand percentage. These data were interpreted by ANOVA and mean comparisons analysis methods. Results showed that pH, gypsum content and sand percentage had statistically significant differences between four erosion types. Mean comparison showed that significant difference of pH, was between mass and badland erosions, sand between badland and gully ones, and gypsum, rill and gully, also badland and gully ones.
Amir Samadi Tabrizi; Hamid Reza Peyrowan; Ahmad Motamed
Abstract
This study is about the relation between erodibility rate and plasticity features ofNeogene Marl deposits of Gatchab and Gitcha in southeast of Garmsar. The erosions alfeature of Neogene sediments are rill, gully and waterway shapes. The depth of soilsampling for rill and waterway types is from surface ...
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This study is about the relation between erodibility rate and plasticity features ofNeogene Marl deposits of Gatchab and Gitcha in southeast of Garmsar. The erosions alfeature of Neogene sediments are rill, gully and waterway shapes. The depth of soilsampling for rill and waterway types is from surface to 30-centimeter thickness and forgully one is from head cut and all outcrop of gully bank. The engineering analyses forsediments include liquid limit, plastic limit and plastic index and engineeringgranulometry. On the basis of engineering classification of soil, the sediment ofGatchab and Siahkoh mountains are fine grained soils with low to very low degreecohesive, consequently low plastic limit and low internal consistency. The comparisonof the results between marl units of Gatchab and Gitcha area have shown the M2 unithas low plasticity and high sensitive to erosion to other units M1 and M2. By the way,the M1 unit is high resistance to water erosion in comparison to M3 unit. From allaspect, Abundance of the lime and clay particle amounts is positive effects ondecreasing of sensitivity rate to erosion of Neogene deposits. The above mentionedresults base on plasticity features of Neogene deposits confirmed by field witness.
Manouchehr Amiri; Hadi Nazari pouya; Hamid Reza Peyrovan
Volume 1, Issue 3 , October 2009, , Pages 179-188
Abstract
The marl soil types are very sensitive to erosion and are deposited into reservoirs of dams and areas of flood spreading in form of considerable sediment annually. This process increases the expenses of filtration of drinkable water and pre-filtration of water of artificial recharge severely. So the ...
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The marl soil types are very sensitive to erosion and are deposited into reservoirs of dams and areas of flood spreading in form of considerable sediment annually. This process increases the expenses of filtration of drinkable water and pre-filtration of water of artificial recharge severely. So the investigation of marl soil types from different aspects is very important for experts and researchers. In this research, it was tried to recognize the effective variables on erosion rate of marls in Hamedan province. 49 samples of 41 spots in 3 marl areas were taken to determine the physical and chemical properties. The characteristics of place of sampling like; slope, geographical situation and privilege of 7 parameters for surface factor of soil were noted. Also, the test of simulated rain was done by the Kamphorst΄s rainfall simulator apparatus in the 41 above spots and 41 samples of runoff were taken and the amount of soil lost were measured and calculated by simple method in the laboratory. The amounts of 23 physical and 15 chemical variables were determined. Then, all data were evaluated by Kolmogorov-Smirnov test and the abnormal data were normalized by logarithm and were evaluated by correlation, bi-variate and multivariate regression tests. The results showed that only 9 variables have significant and linear relation with soil loss, where plastic index, clay percent and clay ratio are the most important variables for evaluation of marl soil loss at marls of investigated areas respectively.
