• 한국농공학회지
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• 제35권2호
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• pp.104-115
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• 1993

The objectives of this paper were to develop predictive equations for reservoir deposits and watershed sediment yields based on sediment survey data for irrigation reservoirs. Hundred reservoirs of various sizes, which have the surveyed data for sediment deposits, were chosen and fourteen watershed physiological and hydrological parameters were investigated. Correlationships between watershed parameters and sediment deposits were investigated and a best fit regression equation was derived, which may be applied for estimating reservoir sediment deposits. The sediment deposits were converted to the watershed sediment yields by applying the trap efficiencies and specific weights. The resulting sediment yields were related to watershed parameters and an empirical predictive equation was also proposed that may be used for rough estimations of watershed sediment yields.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권2호
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• pp.277-286
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• 2013

Cross-shore sediment transport is very important factor in the design of coastal structures, and the beach profile is mainly affected by a number of parameters, such as wave height and period, beach slope, and the material properties of the bed. In this study cross-shore sediment movement was investigated using a physical model and various offshore bar geometric parameters were determined by the resultant erosion profile. The experiments on cross- shore sediment transport carried out in a laboratory wave channel for initial base slopes of 1/8, 1/10 and 1/15. Using the regular waves with different deep-water wave steepness generated by a pedal-type wave generator, the geometrical of sediment transport rate and considerable characteristics of beach profiles under storm conditions and bar parameters affecting on-off shore sediment transport are investigated for the beach materials with the medium diameter of $d_{50}$=0.25, 0.32, 0.45, 0.62 and 0.80 mm. Non-dimensional equations were obtained by using linear and non-linear regression methods through the experimental data and were compared with previously developed equations in the literature. The results have shown that the experimental data fitted well to the proposed equations with respect to the previously developed equations.

• International Journal of Ocean System Engineering
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• 제2권1호
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• pp.1-7
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• 2012

The cross-shore sediment transport in a coastal region causes the important changes in beach morphological properties. The accurate estimation of the cross-shore sediment transport is important for the designing of the marine structures such as seawalls, jetties, breakwaters etc, and the preventing coastal erosion and accretion due to on-off shore sediment transportation. In this study, the experiments on cross- shore sediment transport carried out in a laboratory wave channel for initial beach slopes of 1/8, 1/10 and 1/15. Using the regular waves with different deep-water wave steepness generated by a pedal-type wave generator, the geometrical characteristics of beach profiles under storm conditions and the parameters affecting on-off shore sediment transport are investigated for the beach materials having medium diameters of $d_{50}$=0.25, 0.32, 0.45, 0.62 and 0.80 mm. The experimental results obtained from this study compared with previous experimental work and found to be of the same magnitude as the experimental measurements and followed the expected basic trend.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1057-1064
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• 2009

Since the global warming causes debris flow damage has increased in Kangwon Area, Sediment control dam have increasingly founded to protect the damage. In spite of the realities design methods are well not established to determine type of the dam, design parameters and maintenance. Through comparison for design methods to sediment control dam in Korea, it raised some points to improve to correspond with realities. In addition, it pointed that some issues for the sediment control dams in Kangwon Area. Those are shown that unclear positions of the dams, unremoval of sediment, occurrence of seepage under the dams and uninstallation of roads to remove sediment. In addition, the countermeasure for the issues are proposed.

• 한국환경과학회지
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• 제7권5호
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• pp.581-590
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• 1998

This st at the development of the adequate sediment yield formulas in Wi-Stream basin ; IHP representative basin in Korea. As a result of applying outstanding sediment yield formulas among the existing formulas, it is analyzed that including the Engelund ＆ Hansen formula, Yang formula is proper to the Wi-Stream basin. And as a result of sensitivity analysis to the sediment parameters it is analyzed that Rijn and Actors ＆ White formula is more sensible than any other formulas which has been applied the velocity and depth among the parameters. Also, Engelund ＆ Hansen and Yang formula is less sensible than any other formulas. In Wi-Stream basin, it is analyzed that Yang and Engelund ＆ Hansen formula is the most suitable sediment yield formula in this study. But because the existing formulas had been developed in foreign countries and applied the foreign natural livers and reservoirs, it makes careful use of Korean alluvial river and hoped that it will be developed the most adequate formula in Wi-Stream basin.

• 한국환경과학회지
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• 제16권12호
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• pp.1319-1324
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• 2007

A tank model in conjunction with Kalman filter is developed for prediction of sediment yield from an upland watershed in Northwestern Mississippi. The state vector of the system model represents the parameters of the tank model. The initial values of the state vector were estimated by trial and error. The sediment yield of each tank is computed by multiplying the total sediment yield by the sediment yield coefficient. The sediment concentration of the first tank is computed from its storage and the sediment concentration distribution(SCD); the sediment concentration of the next lower tank is obtained by its storage and the sediment infiltration of the upper tank; and so on. The sediment yield computed by the tank model using Kalman filter was in good agreement with the observed sediment yield and was more accurate than the sediment yield computed by the tank model.

• International Journal of Fluid Machinery and Systems
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• 제10권2호
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• pp.146-153
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• 2017

Sediment flow through hydropower components causes hydro-abrasive erosion resulting in loss of efficiency, interruptions in power production and downtime for repair/maintenance. Online instruments are required to measure/capture the variations in sediment parameters along with collecting samples manually to analyse in laboratory for verification. In this paper, various sediment parameters viz. size, concentration (TSS), shape and mineral composition relevant to hydro-abrasive erosion were measured and discussed with respect to a hydropower plant in Himalayan region, India. A multi-frequency acoustic instrument was installed at a desilting chamber to continuously monitor particle size distribution (PSD) and TSS entering the turbine during 27 May to 6 August 2015. The sediment parameters viz. TSS, size distribution, mineral composition and shape entering the turbine were also measured and analysed, using manual samples collected twice daily from hydropower plant, in laboratory with instruments based on laser diffraction, dynamic digital image processing, gravimetric method, conductivity, scanning electron microscope, X-ray diffraction and turbidity. The acoustic instrument was able to capture the variation in TSS; however, significant deviations were found between measured mean sediment sizes compared to values found in the laboratory. A good relation was found for turbidity ($R^2=0.86$) and laser diffraction ($R^2=0.93$) with TSS, which indicated that turbidimeter and laser diffraction instrument can be used for continuous monitoring of TSS at the plant. Total sediment load passed through penstock during study period was estimated to be 15,500 ton. This study shall be useful for researchers and hydropower managers in measuring/monitoring sediment for hydro-abrasive erosion study in hydropower plants.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권1호
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• pp.29-36
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• 1998

An instantaneous unit sediment graph (IUSG) model is investigated for prediction of sediment yield from an upland watershed in Northwestern Mississippi. Sediment yields are predicted by convolving source runoff with an IUSG. The IUSG is the distribution of sediment from an instantaneous burst of rainfall producing one unit of runoff. The IUSG, defined as a product of the sediment concentration distribution (SCD) and the instantaneous unit hydrograph (IUH), is known to depend on the characteristics of the effective rainfall. The IUH is derived by the Nash model for each event. The SCD is assumed to be an exponential function for each event and its parameters were correlated with the effective rainfall characteristics. A sediment routing function, based on travel time and sediment particle size, is used to predict the SCD.

• 한국환경과학회지
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• 제2권1호
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• pp.29-36
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• 1993

An instantaneous unit sediment graph (IUSG) model is investigated for prediction of sediment yield from an upland watershed In Northwestern Mississippi. Sediment yields are predicted by convolving source runoff with an IUSG. The IUSG is the distribution of sediment from an instantaneous burst of rainfall producing one unit of runoff. The IUSG, defined as a product of the sediment concentration distribution (SCD) and the instantaneous unit hydrograph (IUH), is known to depend on the characteristics of the effective rainfall. The IUH is derived by the Nash model for each event. The SCD is assumed to be an exponential function for each event and its parameters were correlated with the effective rainfall characteristics. A sediment routing function, based on travel time and sediment particle size, is used to predict the SCD.

• 자원환경지질
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• 제27권6호
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• pp.579-592
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• 1994

A case study is presented where a fluvial system is modeled in three dimensions and compared to data gathered from a study of the Arkansas River. The data is unique in that it documents changes that affected a straight channel that was excavated within the river by the U.S. Army Corps of Engineers. Excavation plan maps and sequential aerial photographs show that the channel underwent massive deposition and channel migration as it returned to a more natural, meandering path. These records illustrate that stability of fluvial system can be disrupted either by catastrophic events such as floods or by subtle events such as the altering of a stream's equilibrium base level or sediment load. SEDSIM, Stanford's Sedimentary Basin Simulation Model, is modified and used to model the Arkansas River and the geologic processes that changed in response to changing hydraulic and geologic parameters resulting from the excavation of the channel. Geologic parameters such as fluid and sediment discharge, velocity, transport capacity, and sediment load are input into the model. These parameters regulate the frequency distribution and sizes of sediment grains that are eroded, transported and deposited. The experiments compare favorably with field data, recreating similar patterns of fluid flow and sedimentation. Therefore, simulations provide insight for understanding and spatial distribution of sediment bodies in fluvial deposits and the internal sedimentary structure of fluvial reservoirs. These techniques of graphic simulation can be contributed to support the development of the new design criteria compatible with natural stream processes, espacially drainage problem to minimize environmental disruption.