Hydrogeomorphology
Fariba Karami; Davoud Mokhtari; Farnush Ahmadi
Abstract
The aim of this study is to estimate the rate of soil erosion and its relationship with landforms of Zonuzchay catchment in Marand city. In this study to estimate the rate of soil erosion and sediment production, the modified global model of soil loss (RUSEL), geographic information system (GIS) and ...
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The aim of this study is to estimate the rate of soil erosion and its relationship with landforms of Zonuzchay catchment in Marand city. In this study to estimate the rate of soil erosion and sediment production, the modified global model of soil loss (RUSEL), geographic information system (GIS) and remote sensing (RS) was used. To implement the model, rainfall erosivity factors (R), soil erodibility factor (K), slope length-gradient factor (LS), support practice factor (P), and cover-management factor (C) in Arc GIS environment calculated and Then a soil erosion map was drawn. Topographic position index (TPI) was used to classify and map the landforms of the basin. Then, the role of different landforms in relation to soil erosion rates was investigated by combining relevant maps. The results showed that the values of soil erosion in Zonuzchay basin vary between 0 and 50.20 tons per hectare per year. Valleys and cuts located on heights and slopes have the highest rate of erosion and low-slope domains and flat areas and plains include areas with low and very low erosion. In Zonuzchay basin, soil erosion is mostly on the builders of Flysch type deposits, red and gray conglomerates with Marny layers and alluvial terraces. Investigation of regression relationships between (RUSLE) model factors and soil erosion of Zonuzchay basin showed that the slope length-gradient factor has the greatest effect in calculating the rate of erosion of Zonuzchay basin. .
Hydrogeomorphology
Mohammad Hossein Rezaei Moghaddam; Fariba Karami; Kolson Abazari
Abstract
Floods are one of the most destructive natural disasters that cause huge and frequent human losses ,financial and resource losses all over the world(Mishra & Sinha, 2020,1). Flash floods are caused by heavy rains and due to the sudden accumulation and release of runoff from upstream to downstream. ...
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Floods are one of the most destructive natural disasters that cause huge and frequent human losses ,financial and resource losses all over the world(Mishra & Sinha, 2020,1). Flash floods are caused by heavy rains and due to the sudden accumulation and release of runoff from upstream to downstream. This natural phenomenon is the result of the activity of two groups of different parameters. The first group is the meteorological features that change according to space and time. The second group of fixed parameters includes geomorphological and geological characteristics(Youssef et al, 2011,755).Therefore, identification and zoning of areas prone to flood risk is necessary for sustainable development planning and protection of human societies(Farhan & Ayed, 2017, 719). The Ojan Chai basin, which has been flooded in recent years, especially due to human intervention in basin system. One of the most unprecedented floods occurred in this basin in 2016. Therefore, according to the history of flooding in this basin, it is necessary to assess and zoning the risk of sudden flood. The aim of the current research is to evaluate and zoning flash flood-prone areas in the basin based on physiographic characteristics, which is the basis of the modified flash flood potential index (MFFPI).
Geomorphology
Ali Bigham; S.Asedolah Hejazi; Mohammad Hossein Rezaei Moghaddam; Jamshid Yarahmadi; Fariba Karami
Abstract
Changes in erosion and sedimentation of the basin are one of the most important factors that affect different parts of human life and natural life. it is very necessary to receive these changes quantitatively, which mainly take place under temperature fluctuations and climate changes in different regions, ...
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Changes in erosion and sedimentation of the basin are one of the most important factors that affect different parts of human life and natural life. it is very necessary to receive these changes quantitatively, which mainly take place under temperature fluctuations and climate changes in different regions, in order to be more prepared to deal with its negative consequences. In this research, erosion and sedimentation changes in Hajiler watershed were investigated and predicted using GeoWEPP and SWAT models. Based on this, first, by using the data of the current situation of the Ahar synoptic station and using the SDSM model, the changes of the statistical period2020-2040 in three scenarios RCP2.6-RCP4.5-RCP8.5 were investigated, then simulation and prediction of erosion changes was carried out. and sedimentation was done under the influence of climate change by using popular models. The output of the SDSM model indicates an increase in temperature and a decrease in rainfall for the basin until 2040.And the analysis of the simulation results of the sedimentation rate of the models showed that in the studied basin, the GeoWEPP with the selection of the domain method has a suitable level in estimating the sedimentation rate compared to observational statistics. The final model was chosen to predict the amount of sediment in the mentioned period of the basin. Using the downscaled results of the atmospheric general circulation model, the sediment changes in the statistical period of 2020-2040 under the above mentioned three scenarios were estimated as -1.97, 4.45, and 2.98, respectively.
Fariba Karami; Maryam Bayati Khatibi
Volume 6, Issue 18 , June 2019, , Pages 115-137
Abstract
IntroductionSoil erosion is one of the most serious environmental degradation problems that adversely affects many natural and human-managed ecosystems. In agricultural watersheds, soil erosion not only removes nutrient-rich top soil on site, but also degrades water quality as a result of transported ...
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IntroductionSoil erosion is one of the most serious environmental degradation problems that adversely affects many natural and human-managed ecosystems. In agricultural watersheds, soil erosion not only removes nutrient-rich top soil on site, but also degrades water quality as a result of transported sediments off site. The estimation of soil erosion is often complicated due to the complex interplay of many factors such as climate, land cover, soil, topography, lithology, and human activities. Erosion models can be used as predictive tools for soil loss assessment, conservation planning, soil erosion inventories, and project planning. Moreover, models can be used as tools for understanding erosion processes and their impact. They are basically categorized into three types of empirical, conceptual, and physical based models. Empirical models are usually statistical in nature and generally applicable only to conditions for which the parameters have been calibrated. The commonly used empirical soil erosion models are USLE, RUSLE, and MUSLE. Soil erosion based- physical models include AGNPS, WEPP, SWAT, and the like. One of the most widely applied watershed models is SWAT which has been extensively used for simulating hydrologic and water quality processes in watersheds with a wide range of scales and environmental conditions. Iran is among the most affected countries in the world in terms of the extent and intensity of soil erosion. Current estimates suggest that soil erosion in Iran is around 25 tons per hectare annually which is four times greater than the world average. In the Northwest of the country, the Sattarkhan Dam has been constructed on the Aharchay River, which is the source of drinking water, agriculture, and industry in the region. In the catchment area of the Sattarkhan Dam, which includes the Aharchay upstream, physical conditions such as being mountainous and the unstability of land management such as the spread of rainforests with plowing in the direction of gradient and developmental activities cause soil erosion, sediment production, damping reservoir capacity reduction and increasing reservoir sedimentation costs. The goal of this study was to model and evaluate the spatial distribution of soil erosion in the Sattarkhan Dam basin. In this study, Soil and Water Assessment Tool (SWAT) and MUSLE models were served for simulating sediment yield and identifying critical areas of soil erosion in the Sattarkhan Dam basin, located in the North West of Iran.MethodologyThe SWAT model is a continuous-time, semi-distributed, process-based river basin or watershed scale model. It was developed to predict the impact of land management practices on water, sediment and chemical yields in agricultural watersheds with varying soils, land use, and management conditions over a long period of time. It divides a watershed into sub watersheds. Each sub watershed is connected through a stream channel. In addition, each sub watershed is divided into Hydrologic Response Unit (HRU). HRU is a unique combination of soil, land use, and slope type in a sub watershed. SWAT predicts the sediment yield within each HRU using Modified Universal Soil Loss Equation (MUSEL). Sequential Uncertainty Fitting-2 (SUFI-2), a SWAT-CUP2012 sub-module computer program, was applied to optimize the parameters of the SWAT using monthly observed sediment yield data at a monitoring site in the Sattarkhan Dam basin. In this study, sediment discharges data series during 2004-2009 and 2010-2013 were respectively used for model calibration and validation. To evaluate model performance, the statistical methods consisted of the determination coefficient (R2), Nash-Sutcliffe coefficient (NS), and root mean square error observations standard deviation ratio (RSR).Results and DiscussionSeven highly sensitive parameters were recognized for sediment yield simulation including CN2, ESCO, CH_K2, SMFMN, CH_N2, PRF, and USLE_K. The calibration outputs for simulation showed a very good model performance for sediment yield where the values of R2, NS and RSR were respectively 0.76, 0.95, and 0.06. During the validation period, the annual sediment yield simulation of R2, NS, and RSR values were respectively 0.96, 0.93, and 0.1. Also, the results showed that the spatial pattern of the regions differed in terms of the erosion and sediment production. The critical areas were located in the upper part of the basin and sediment production was very high and high, which included about 34.15% of the area of the Sattarkhan Dam basin.Conclution This study showed that the SWAT model is competent of predicting sediment yields and, hence, can be used as a tool for water resource planning and management in the study watershed. The prediction of sediment yield at ungauged watershed with SWAT could be possible under comparable topography, land use, soil management, climate condition for the purpose of soil erosion assessment, scenario analysis, and recommendation of best management practices to support watershed management initiatives in the semi-dry mountainous regions of Iran.
Maryam Bayati Khatibi; Fariba Karami
Volume 5, Issue 14 , June 2018, , Pages 67-89
Abstract
Introdution
Alluvial floodplains, and in particular those associated with the world's largest rivers, have a complex relief that is produced by recurring erosional, and depositional events.The magnitude, heterogeneity, spatial distribution, and connectivity of this relief controls river floodwater ...
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Introdution
Alluvial floodplains, and in particular those associated with the world's largest rivers, have a complex relief that is produced by recurring erosional, and depositional events.The magnitude, heterogeneity, spatial distribution, and connectivity of this relief controls river floodwater routing and storage, sediment dispersal, and biogeochemical cyclingChannel Lateral movement and course changes are main causes for floodplain extend ,bank erosion and soil loss due to cut bank .Aras river that located in NW of Iran(from 45°E to 48°E), have many curvatures on course and due to this reason Aras is made high rate movement yearly .Aras is a boarder river and for this reason is very important that direction is determined .
Methodology
In this article for determining the rate of lateral movement is used landsats 5,2 (Mss) landsat5™landsat 7(ETM+) and landsats(OLI) with 30 and 15 resoulation in 1985 to 2015 epoch. In this study is used Rm, R and MI for rate and degree movement and rate of river course curvature .
In order to determining of power flow against instability of mater in this article is used MI idex:
MI=S√Q/D50
And for determining of rate of displacement of channel, is used of Rm index:
Rm=(A/L)/Y
Discusses
Investigation on the curvature radial Aras channel show that average rate of radial is 509.62 m. In other site this rate is 515.71 m. The study also show that changes in Aras river course is vary .When wide is high ,channel migration is excess .In recent time this changes is high ,but rate of migration in Iran site and other site is decrease to compare of past time .The average of channel migration to Iran site is 27,21m in 2010 and other site rate is 28,32 m.
Results
Sum all area that located at other site due to displacement are 1410255 m3 (1985-2015).Area in site of Iran is 2230869 m3 (1985-2015).That is to say ,difference is 820614 m3.This has meaning that our land and soil is placed other site due to channel movement .Yearly average displacement of channel Aras river is 475 m at Iran site and 353 m at other site .So ,displacement at two site is vary .Over the past three decades, the fluvial dynamics of meander bends, including processes related to outer bank erosion, have been the focus of numerous scientific investigations. Despite this effort,a comprehensive understanding of the hydraulic processes of outer bank erosion—especially the role of flow turbulence—remains elusive.Because natural river flows are fully turbulent, the erosive stresses acting on the banks of meandering rivers should be related to turbulent stresses. Current models of outer bank erosion, however, rely on simple parameterization of the flow via excess velocity, excess shear stress at the bank toe, or excess flow depth .
Aras River is very dynamic .This river make curvature in its curse and cut bank .When river make meander in flow curse ,cut power of flow is increase .This high power is energy for bank cut and movement .Soil lost is other result for cut bank .This story is happened in northern border of Iran .
Mussa Abedini; Fariba Karami; Nader Sarmasti
Volume 2, Issue 5 , January 2017, , Pages 17-40
Abstract
Tabriz metropolitan is located in an area of active fault which crosses the lower part of the Gomanabchai and Varkeshchai watershed in the north of the city. This research is studying Tabriz fault tectonic activity in the range of Tabriz metropolitan using geomorphic indicators, remote sensing and GIS ...
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Tabriz metropolitan is located in an area of active fault which crosses the lower part of the Gomanabchai and Varkeshchai watershed in the north of the city. This research is studying Tabriz fault tectonic activity in the range of Tabriz metropolitan using geomorphic indicators, remote sensing and GIS techniques. To achieve this goal, geomorphic indicators were used as tools including drainage density, branching ratio, the ratio of the basin, basin asymmetry, polarity reverse topographic, hypsometric integral, sinus mountain front, sinus river valley floor width to valley height, longitudinal gradient, and index assessment of active tectonic model and concept. Satellite images ASTER sensor, geological maps, digital elevation model and ENVI4.8, ArcGIS10.2 software were other physical means in this research. As a result, small amounts of drainage density indices 0.51 and 0.57, the branch 2 and 2.1, 2.2 and 1.8 of the basin, basin asymmetry 39.7 and 23.2, 0.36 and 0.59 reverse topographic symmetry, hypsometric integral 0.28 and 0.39, 1.4 sinus mountain front and 0.93, 1.1 and 1.3 sinus river, valley floor width to valley height of 1.08 and 1.2, longitudinal gradient the 1202 and 318 calculated for Gomanabchai and Varkeshchai watershed respectively. Relative Active Tectonics Index assessment showed that Gomanabchai and Varkeshchai watershed values 1.9 and 1.7 respectively have high tectonic movements. Results indices show Gomanabchai and Varkeshchai watershed morphology influence the Tabriz fault tectonic movements. With processing satellite data, as evidence of tectonic Tabriz fault deviation, Ajichai stream, cliff fault and lens-shaped phenomenon were also interpreted in the metropolitan area Tabriz. The results were confirmed by field evidence area. So, Tabriz was located as a perilous zone of tectonic movement.
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.
Abstract
Abstract
In recent years geomorphological instantaneous unit hydrograph approach has gained wide acceptability in estimating the runoff from a watershed due to different storm patterns and watersheds with scanty data. Using geomorphologic features is a suitable criterion for derivation of hydrograph ...
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Abstract
In recent years geomorphological instantaneous unit hydrograph approach has gained wide acceptability in estimating the runoff from a watershed due to different storm patterns and watersheds with scanty data. Using geomorphologic features is a suitable criterion for derivation of hydrograph and watershed management in ungagged watersheds. In this study, using morphometric characteristics of Daryan Chay basin, such as bifurcation ratio and longest flow path, geomorphological instantaneous unit hydrographs which were derived for 5 events and by using criterion such as determination coefficient, percentage error in peak discharge and time to peak discharge, Nash-Sutcliffe efficiency and percentage error in runoff volume were compared with observed hydrographs. The findings showed that the most important components of the hydrograph were time to peak and peak discharge. A slight difference was observed between simulated time to peak using geomorphological instantaneous unit hydrograph and observed hydrograph. In other words, geomorphologic instantaneous unit hydrograph predicted the geomorphological instantaneous unit hydrograph accordingly.
