scholarly journals Distributed modeling of soil erosion and sediment transport

2018 ◽  
Vol 34 (2) ◽  
pp. 763
Author(s):  
V. HRISSANTHOU ◽  
A. PSILOVIKOS
Keyword(s):  
Sediment Transport ◽  
River Basin ◽  
Sediment Yield ◽  
Surface Erosion ◽  
Rainfall Runoff ◽  
Distributed Modeling ◽  
The Third ◽  
Nestos River ◽  
Under Construction ◽  
The Individual

A mathematical model is used for the estimation of the annual sediment yield resulting from rainfall and runoff at the outlet of Nestos River basin (Toxotes, Thrace, Greece), where the ecologically interesting Nestos delta exists. The model is applied to that part of Nestos River basin (838 km2) which lies downstream of three dams. Two dams (Thissavros and Platanovryssi) have been already constructed, while the third one (Temenos) is under construction. The model consists of three sub-models: a rainfall-runoff sub-model, a surface erosion sub-model and a sediment transport sub-model for streams. This model is also capable of computing the annual erosion amount and sediment yield in the individual sub-basins

scholarly journals Estimation of Sediment Yield and Maximum Outflow Using the IntErO Model in the Sarada River Basin of Nepal

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 952 ◽  
Author(s):  
Devraj Chalise ◽  
Lalit Kumar ◽  
Velibor Spalevic ◽  
Goran Skataric
Keyword(s):  
Soil Erosion ◽  
River Basin ◽  
Sediment Yield ◽  
Soil Loss ◽  
Surface Erosion ◽  
Good Opportunity ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Erosion Coefficient ◽  
To Come

Soil erosion is a severe environmental problem worldwide as it washes away the fertile topsoil and reduces agricultural production. Nepal, being a hilly country, has significant erosion disputes as well. It is important to cognise the soil erosion processes occurring in a river basin to manage the erosion severity and plan for better soil conservation programs. This paper seeks to calculate the sediment yield and maximum outflow from the Sarada river basin located in the western hills of Nepal using the computer-graphic Intensity of Erosion and Outflow (IntErO) model. Asymmetry coefficient of 0.63 was calculated, which suggests a possibility of large floods to come in the river basin in the future whereas the maximum outflow from the river basin was 1918 m³ s−1. An erosion coefficient value of 0.40 was obtained, which indicates surface erosion of medium strength prevails in the river basin. Similarly, the gross soil loss rate of 10.74 Mg ha−1 year−1 was obtained with the IntErO modeling which compares well with the soil loss from the erosion plot measurements. The IntErO model was used for the very first time to calculate soil erosion rates in the Nepalese hills and has a very good opportunity to be applied in similar river basins.

scholarly journals SEDIMENT YIELD AND SUSPENDED SEDIMENT TRANSPORT IN THE CHIKUGOGAWA RIVER BASIN

2008 ◽  
Vol 52 ◽  
pp. 553-558 ◽  
Author(s):  
Katsuhide YOKOYAMA ◽  
Shintaro FUJIZUKA ◽  
Tetsuhiro NAKAZAWA ◽  
Soutaro TAKASHIMA
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
River Basin ◽  
Sediment Yield ◽  
Suspended Sediment Transport

scholarly journals Hydrological Modelling of the Mono River Basin at Athiémé

2021 ◽  
Vol 384 ◽  
pp. 57-62
Author(s):  
Eliézer Iboukoun Biao ◽  
Ezéchiel Obada ◽  
Eric Adéchina Alamou ◽  
Josué Esdras Zandagba ◽  
Amédée Chabi ◽  
...  
Keyword(s):  
River Basin ◽  
Climate Models ◽  
Regional Climate ◽  
Regional Climate Models ◽  
Stochastic Approach ◽  
Projection Data ◽  
Rainfall Runoff ◽  
Future Projection ◽  
The Individual ◽  
Modelling Approach

Abstract. The objective of this study is to model the Mono River basin at Athiémé using stochastic approach for a better knowledge of the hydrological functioning of the basin. Data used in this study consist of observed precipitation and temperature data over the period 1961–2012 and future projection data from two regional climate models (HIRHAM5 and REMO) over the period 2016–2100. Simulation of the river discharge was made using ModHyPMA, GR4J, HBV, AWBM models and uncertainties analysis were performed by a stochastic approach. Results showed that the different rainfall-runoff models used reproduce well the observed hydrographs. However, the multi-modelling approach has improved the performance of the individual models. The Hermite orthogonal polynomials of order 4 are well suited for the prediction of flood flows in this basin. This stochastic modeling approach allowed us to deduce that extreme events would therefore increase in the middle of the century under RCP8.5 scenario and towards the end of the century under RCP4.5 scenario.

scholarly journals Process-based distributed modeling approach for analysis of sediment dynamics in a river basin

2010 ◽  
Vol 7 (4) ◽  
pp. 5685-5735
Author(s):  
M. A. Kabir ◽  
D. Dutta ◽  
S. Hironaka
Keyword(s):  
Sediment Transport ◽  
Soil Erosion ◽  
River Basin ◽  
Best Management Practices ◽  
Management Practices ◽  
Sediment Dynamics ◽  
Distributed Hydrological Model ◽  
Distributed Modeling ◽  
Modeling Approach ◽  
Basin Scale

Abstract. Modeling of sediment dynamics for developing best management practices of reducing soil erosion and of sediment control has become essential for sustainable management of watersheds. Precise estimation of sediment dynamics is very important since soils are a major component of enormous environmental processes and sediment transport controls lake and river pollution extensively. Different hydrological processes govern sediment dynamics in a river basin, which are highly variable in spatial and temporal scales. This paper presents a process-based distributed modeling approach for analysis of sediment dynamics at river basin scale by integrating sediment processes (soil erosion, sediment transport and deposition) with an existing process-based distributed hydrological model. In this modeling approach, the watershed is divided into an array of homogeneous grids to capture the catchment spatial heterogeneity. Hillslope and river sediment dynamic processes have been modeled separately and linked to each other consistently. Water flow and sediment transport at different surface grids and river nodes are modeled using one-dimensional kinematic wave approximation of Saint-Venant equations. The mechanics of sediment dynamics are integrated into the model using representative physical equations after a comprehensive review. The model has been tested on river basins in two different hydro climatic areas, the Abukuma River Basin, Japan and Latrobe River Basin, Australia. Sediment transport and deposition are modeled using Govers transport capacity equation. All spatial datasets, such as, Digital Elevation Model (DEM), land use and soil classification data, etc., have been prepared using raster "Geographic Information System (GIS)" tools. The results of relevant statistical checks (Nash-Sutcliffe efficiency and R-squared value) indicate that the model simulates basin hydrology and its associated sediment dynamics reasonably well. This paper presents the model including descriptions of the various components and the results of its application on case study areas.

scholarly journals Process-based distributed modeling approach for analysis of sediment dynamics in a river basin

2011 ◽  
Vol 15 (4) ◽  
pp. 1307-1321 ◽  
Author(s):  
M. A. Kabir ◽  
D. Dutta ◽  
S. Hironaka
Keyword(s):  
Sediment Transport ◽  
Soil Erosion ◽  
River Basin ◽  
Best Management Practices ◽  
Management Practices ◽  
Sediment Dynamics ◽  
Distributed Hydrological Model ◽  
Distributed Modeling ◽  
Modeling Approach ◽  
Basin Scale

Abstract. Modeling of sediment dynamics for developing best management practices of reducing soil erosion and of sediment control has become essential for sustainable management of watersheds. Precise estimation of sediment dynamics is very important since soils are a major component of enormous environmental processes and sediment transport controls lake and river pollution extensively. Different hydrological processes govern sediment dynamics in a river basin, which are highly variable in spatial and temporal scales. This paper presents a process-based distributed modeling approach for analysis of sediment dynamics at river basin scale by integrating sediment processes (soil erosion, sediment transport and deposition) with an existing process-based distributed hydrological model. In this modeling approach, the watershed is divided into an array of homogeneous grids to capture the catchment spatial heterogeneity. Hillslope and river sediment dynamic processes have been modeled separately and linked to each other consistently. Water flow and sediment transport at different land grids and river nodes are modeled using one dimensional kinematic wave approximation of Saint-Venant equations. The mechanics of sediment dynamics are integrated into the model using representative physical equations after a comprehensive review. The model has been tested on river basins in two different hydro climatic areas, the Abukuma River Basin, Japan and Latrobe River Basin, Australia. Sediment transport and deposition are modeled using Govers transport capacity equation. All spatial datasets, such as, Digital Elevation Model (DEM), land use and soil classification data, etc., have been prepared using raster "Geographic Information System (GIS)" tools. The results of relevant statistical checks (Nash-Sutcliffe efficiency and R–squared value) indicate that the model simulates basin hydrology and its associated sediment dynamics reasonably well. This paper presents the model including descriptions of the various components and the results of its application on two case study areas.

scholarly journals Multi-Spatial Resolution Rainfall-Runoff Modelling—A Case Study of Sabari River Basin, India

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1224
Author(s):  
Vimal Chandra Sharma ◽  
Satish Kumar Regonda
Keyword(s):  
River Basin ◽  
Spatial Resolution ◽  
Large Data ◽  
River Basins ◽  
Rainfall Runoff ◽  
Distributed Modeling ◽  
Distribution Mode ◽  
Streamflow Estimation ◽  
Data Requirements ◽  
Lumped Modeling

One of the challenges in rainfall-runoff modeling is the identification of an appropriate model spatial resolution that allows streamflow estimation at customized locations of the river basin. In lumped modeling, spatial resolution is not an issue as spatial variability is not accounted for, whereas in distributed modeling grid or cell resolution can be related to spatial resolution but its application is limited because of its large data requirements. Streamflow estimation at the data-poor customized locations is not possible in lumped modeling, whereas it is challenging in distributed modeling. In this context, semi-distributed modeling offers a solution including model resolution and estimation of streamflow at customized locations of a river basins with less data requirements. In this study, the Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) model is employed in semi-distribution mode on river basins of six different spatial resolutions. The model was calibrated and validated for fifteen and three selected flood events, respectively, of three types, i.e., single peak (SP), double peak (DP)- and multiple peaks (MP) at six different spatial resolution of the Sabari River Basin (SRB), a sub-basin of the Godavari basin, India. Calibrated parameters were analyzed to understand hydrologic parameter variability in the context of spatial resolution and flood event aspects. Streamflow hydrographs were developed, and various verification metrics and model scores were calculated for reference- and calibration- scenarios. During the calibration phase, the median of correlation coefficient and NSE for all 15 events of all six configurations was 0.90 and 0.69, respectively. The estimated streamflow hydrographs from six configurations suggest the model’s ability to simulate the processes efficiently. Parameters obtained from the calibration phase were used to generate an ensemble of streamflow at multiple locations including basin outlet as part of the validation. The estimated ensemble of streamflows appeared to be realistic, and both single-valued and ensemble verification metrics indicated the model’s good performance. The results suggested better performance of lumped modeling followed by the semi-distributed modeling with a finer spatial resolution. Thus, the study demonstrates a method that can be applied for real-time streamflow forecast at interior locations of a basin, which are not necessarily data rich.

scholarly journals EFFICIENCY OF INTERO MODEL TO PREDICT SOIL EROSION INTENSITY AND SEDIMENT YIELD IN KHAMSAN REPRESENTATIVE WATERSHED (WEST OF IRAN)

AGROFOR ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Abdulvahed KHALEDI DARVISHAN ◽  
Mohamad DERIKVANDI ◽  
Ramyar ALIRAMAEE ◽  
Mohsen KHORSAND ◽  
Velibor SPALEVIC ◽  
...  
Keyword(s):  
Soil Erosion ◽  
River Basin ◽  
Sediment Yield ◽  
Peak Flow ◽  
Empirical Models ◽  
Spatial And Temporal Variation ◽  
Surface Erosion ◽  
Erosion Process ◽  
Yield Data ◽  
Erosion Material

Application of empirical models is inevitable because of the complexity of process,features, spatial and temporal variation of soil erosion and non-existence or lack ofassociated data. In the present study, maximum outflow and soil erosion intensitywere predicted for Khamsan representative watershed in West of Iran, using IntEromodel. The results of production of erosion material in the river basin (W year),coefficient of the deposit retention (Ru) and real soil losses (G year) were thencompared with the measured soil erosion, SDR and sediment yield data inKhamsan watershed. The intensity of the erosion process were medium in studiedwatershed. The predicted data were compared with the measured sediment yield ofstudied watershed and verified the acceptable results of the IntEro model inKhamsan representative watershed. The results showed that the peak flow is 27.50m3s-1 for a return period of 100 years. The value of Z coefficient of 0.876 indicatesthat the river basin belongs to the second destruction category out of five. Thecalculated net soil loss from the river basin was 12263.44 m3 per year, specific282.81 m3km-2 per year. The strength of the erosion process is strong, andaccording to the erosion type, it is surface erosion.

scholarly journals River improvement techniques for mitigating river bed degradation and channel width reduction in the sandy Hii River where sediment transport occurs at normal times

2018 ◽  
Vol 40 ◽  
pp. 02033
Author(s):  
Takahisa Gotoh ◽  
Shoji Fukuoka
Keyword(s):  
Sediment Transport ◽  
River Basin ◽  
Sediment Yield ◽  
Main Channel ◽  
Channel Width ◽  
Sand Waves ◽  
Check Dams ◽  
River Bed ◽  
Width Reduction ◽  
Non Equilibrium

In the sandy Hii River, a large amount of sediment yield from upper river basin had brought developments of braided channels covered with sand waves. In the braided channels, sediment materials on the river beds are capable to move in normal discharge conditions. In recent years, however, the sediment yield decreases due to constructions of check dams and ground sills in the upper river basin. Thus, the river beds downstream of the ground sill have gradually degraded and the main channel widths have been narrowed with the progressing bed degradation. Firstly, we clarified that the effects of non-equilibrium sediment transports around the ground sill during normal discharge conditions on the bed degradation and the channel width reduction by using annual observed data and numerical simulations for bed variations. In addition, we provided the river improvement techniques for mitigating bed degradation and channel width reduction by improving state of non-equilibrium sediment transports passing through the ground sill.

Combining Values

2002 ◽  
Vol 7 (2) ◽  
pp. 1-4, 12 ◽  
Author(s):  
Christopher R. Brigham
Keyword(s):  
Lower Extremity ◽  
Upper Extremity ◽  
Evaluation Method ◽  
Proximal Phalanx ◽  
Common Error ◽  
The Third ◽  
Whole Person ◽  
Impairment Ratings ◽  
Upper Extremity Impairment ◽  
The Individual

Abstract To account for the effects of multiple impairments, evaluating physicians must provide a summary value that combines multiple impairments so the whole person impairment is equal to or less than the sum of all the individual impairment values. A common error is to add values that should be combined and typically results in an inflated rating. The Combined Values Chart in the AMA Guides to the Evaluation of Permanent Impairment, Fifth Edition, includes instructions that guide physicians about combining impairment ratings. For example, impairment values within a region generally are combined and converted to a whole person permanent impairment before combination with the results from other regions (exceptions include certain impairments of the spine and extremities). When they combine three or more values, physicians should select and combine the two lowest values; this value is combined with the third value to yield the total value. Upper extremity impairment ratings are combined based on the principle that a second and each succeeding impairment applies not to the whole unit (eg, whole finger) but only to the part that remains (eg, proximal phalanx). Physicians who combine lower extremity impairments usually use only one evaluation method, but, if more than one method is used, the physician should use the Combined Values Chart.

Journey to the Advisor Within: Exploring Challenge, Transformation and Evolution in Advisor Stories

Relay Journal ◽  
2019 ◽  
pp. 319-322
Author(s):  
Gamze Güven-Yalçın ◽  
Stephanie Lea Howard ◽  
Hatice Karaaslan
Keyword(s):  
Language Learning ◽  
Reflective Practice ◽  
Message Board ◽  
Initial Experiment ◽  
Narrative Style ◽  
The Third ◽  
Visual Message ◽  
Knowledge And Practice ◽  
The Individual ◽  
Academic Year

In the Reflective Practice column of the third issue of the Relay Journal, Yamamoto (2019) remarked on the importance of creating a platform for advisors to voice their views, feelings, and experiences, and suggested a need for more reflective narratives to be posted from different social, historical, and cultural contexts in order to provide an intimate view inside advising sessions, thereby offering a better understanding of said advising practices. The aim was to create a forum where advisors could learn from each other, and ultimately, everyone could mutually benefit from the experiences shared. To further this innovative research into Advising in Language Learning (ALL), the initial experiment by language advsiors at Kanda has been replicated in a different setting with four learning advisors from Ankara Yıldırım Beyazıt University, Turkey. The design used by the advisors at Kanda, a narrative style adopted while telling the stories, has been expanded to include a visual message board to which 20 learning advisors have contributed with their short reflective captions on their advisor selves. Additionally, the theme used by the advisors at Kanda, “the most memorable advising experience of this academic year” has been altered in our case to avoid repetition and to allow reflection on different aspects of the advising experiences. Thus, our narratives and the visual message board will examine two different themes: (1) How has advising affected you? (2) How do you define yourself as an advisor? Four narratives have elaborated on the first theme of the influence of advising knowledge and practice on the individual advisors, and the visual message board includes 20 images with reflective captions on the second theme of defining advisor identities.

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