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Application of Mathematical Model to Assess sediment movement Pattern along Nearshore Coastal Water

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Journal of Earth Science and Engineering 2016年第3期6卷 177-182页

作者： Sumaya Hossain Department of Water Resource Engineering Bangladesh University of Engineering & Technology Dhaka 1000 Bangladesh

movement of sediment load and its pattern of transportation along nearshore coastal water is a very important phenomenon to be assessed for different sector of coastal Engineering. To develop and understand the physical processes responsible for shaping the ongoing evolution of the coast and to develop the management strategies to deal the impact of human activities on the coastal zone and as well as for adapting to the hazards associated with the people living on the coast, knowledge of the mechanism, processes and the pattern of sediment movement in the nearshore zone is of utmost importance. Nearshore zone is a very active area, where a series of dynamic processes occur in response to changing wave climates and sediment budgets. Nowadays mathematical modeling is an attractive alternative and becoming a very viable approach to study the sediment movement pattern with the advanced computational facilities and improved understanding on wave mechanics and sediment transport processes. It is very effective, reliable and also comfortable to study the pattern of sediment transportation including yield, distribution and management of sediment with the help of mathematical model. Validity of forecast in sediment transport depends on both mathematical modeling technique and boundary conditions.

关键词： sediment movement nearshore zone mathematical model boundary condition.

Temporal and spatial variation in the sediment volume along the beaches between Ovari and Kanyakumari(SE INDIA)

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International Journal of sediment Research 2013年第3期28卷 384-395页

作者： S.SARAVANAN N.CHANDRASEKAR V.JOEVIVEK Centre for GeoTechnology Manonmaniam Sundaranar University Civil Engineering Department Christ the King Engineering College

A 2-year set of profile data from Ovari to Kanyakumari Beach,SE India has been analysed by using empirical orthogonal function(EOF) techniques to identify characteristic patterns of temporal and spatial variation in the sediment volume of the *** results show that variation in the sediment volume of the beach is determined by interaction between the biennial and seasonal *** analysis the pattern of alongshore sediment exchange along the study *** method facilitated separation of onshore-offshore and alongshore modes of sediment transfer and identification of the patterns of alongshore sediment *** eigenfunction modes confirm the dominance of biennial,annual,and biannual sediment transfers occurring on study *** sediment movement along the shoreline of study area is mainly governed by the forces associated with the incoming waves and the availability of sediments within the *** present investigation has been made as an attempt to appreciate the sediment movement in relation to wave activity along the *** longshore sediment transport is intensive in the northerly direction as compared to southerly *** normal condition is for and to be moved annually or more frequently in the shallows and on the *** and wave-driven currents cause longshore drift of sand along the beach and offshore.

关键词： Beach Profile sediment movement Beach volume change India

sediment Deposition and Resuspension in Mouth Bar Area of the Yangtze Estuary

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China Ocean Engineering 2000年第3期15卷 339-348页

作者：李九发何青莉莉沈焕庭 Protessor State Key Laboratory of Estuarine and Coastal Research East China Normal University ECNUShanghai 200062 P. R. China Associate Professor State Key Laboratory of Estuarine and Coastal Research ECNU Shanghai 200062 P. R. China Graduate student State Key Laboratory of Estuarine and Coastal Research ECNU Shanghai 200062 P. R. China

A comprehensive analysis is conducted based on observations on topography, tidal current, salinity, suspended sediment and bed load during the years of 1982, 1983, 1988, 1989. 1996, and 1997 in the Yangtze Estuary. Results show that the deformation of tidal waves is distinct and the sand carrying capacity is large within the mouth bar due to strong tidal currents and large volume of incoming water and sediments. Owing to both temporal and spatial variation of tidal current, deposition and erosion ore extremely active. In general a change of up to 0.1 m of bottom sediments takes place during a tidal period. The maximum siltation and erosion are around 0.2 m in a spring to neap tides cycle. The riverbed is silted during flood when there is heavy sediment load, eroded during dry season when sediment lo:ld is low. The annual average depth of erosion anti siltation on the riverbed is around 0.6 m. In particular cases, it may increase to 1.4 m to 2.4 m at some locations.

关键词： the Yangtze Estuary sediment movement deposition sediment resuspension mouth bar

Estimation of sediment Incipient Velocity Using B-Mode Ultrasound Imaging Technique

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Wuhan University Journal of Natural Sciences 2015年第2期20卷 180-184页

作者： SONG Huan ZOU Xianjian Electronic Information School Wuhan University

sediment incipient velocity （SIV） is a vital parameter for sediment research and river dynamics. This paper describes a novel method of estimating SIV based on the known flow velocity in the movable-bed model experiment. In this method, we use B-mode ultrasound imaging technique to get video images of moving particles and topography under water. By statistical analysis of video images, the relationship between the average number of imaging particles and flow velocity is obtained. The relationship between the change rate of average number and flow velocity is analyzed in sediment incipient process. These relationships are used to estimate the SIV. Lastly, the changed topography verifies the estimated velocity. The results show there is a sudden change in these relationships which can be used to estimate the SIV with high resolution by using a B-mode ultrasound device. The estimated SIV of plastic sands （particle size is about 0.25 mm） is 3.64 cm · s^-1 and the estimated SIV of natural sands （particle size is about 0.25 mm） is 5.47 cm · s^-1in the same condition.

关键词： sediment movement incipient velocity B-mode ultrasound imaging technique particle size

Numerical　simulation　of　sediment　lifted　by　waves　and　transported　by　tidal　currents

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Acta Oceanologica Sinica 1994年第3期13卷 433-443页

作者： Cao Zude and Wang Guifen(Tianjin Research Institute of Water Transport Engineering, Tanggu 300456, Tianjin, China)

The analysis of the scabed processes of a muddy coast has been described in this paper. On the basisof the basic differential equation of tidal current and sediment movement influenced by waves, a numerical simulation system for sediment lifted by waves and transported by tidal currents and scabed processes has been established by using MADI method, and applied to the sea area of Tianjin Port with good results.

关键词： Wave tidal current numerical model sediment movement bed processes

Research on Measurement of Bed Shear Stress Under Wave-Current Interaction

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China Ocean Engineering 2015年第4期29卷 589-598页

作者：徐华夏云峰马炳和郝思禹张世钊杜德军 Nanjing Hydraulic Research Institute College of Harbor Coastal and Offshore Engineering Hohai University The State Key Laboratory of Hydrology-Water Resources & Hydraulic Engineering Waterway and sediment Engineering of the Ministry of Communications Northwestern Polytechnical University

The movement of sediment in estuary and on coast is directly restricted by the bed shear stress. Therefore, the research on the basic problem of sediment movement by the bed shear stress is an important way to research the theory of sediment movement. However, there is not a measuring and computing method to measure the bed shear stress under a complicated dynamic effect like wave and current. This paper describes the measurement and test research on the bed shear stress in a long launder of direct current by the new instrument named thermal shearometer based on micro-nanotechnology. As shown by the research results, the thermal shearometer has a high response frequency and strong stability. The measured results can reflect the basic change of the bed shear stress under wave and wave-current effect, and confirm that the method of measuring bed shear stress under wave-current effect with thermal shearometer is feasible. Meanwhile, a preliminary method to compute the shear stress compounded by wave-current is put forward according to the tested and measured results, and then a reference for further study on the basic theory of sediment movement under a complicated dynamic effect is provided.

关键词： bed shear stress micro-nanotechnology thermal shearometer wave-current effect sediment movement

Numerical Simulation of Wave Field at the Kemena River Mouth in Kalimantan Island

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China Ocean Engineering 1999年第2期14卷 217-224页

作者： Chen, Y Sun, JS Tianjin Res Inst Water Transport Engn Tianjin 300456 Peoples R China

By use of the parabolic equation of numerical simulation of wave which is suitable for large-angle propagation anti Crank-Nicolson differential method, the wave field at the Kemema River mouth has been studied for analysis of sediment movement in the area. In order to reflect wave energy loss accurately, the Bretchneider-Reid formula is quoted and the friction coefficient in the formula is discussed in this paper. The calculation results indicate that the wave becomes a little damped at the mouth of Kemena River influenced by the topography and bottom friction, and the wave at the east beach is higher than that at the west beach, because the east beach extends out.

关键词： parabolic equation wave field numerical simulation river mouth sediment movement

Submerged Geosynthetic Reef as Shore Protection Measure for Islands

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Journal of Marine Science and Application 2022年第1期21卷 128-139页

作者： Vallam Sundar Sannasi Annamalaisamy Sannasiraj Sukanya Ramesh Babu Dipak Kumar Maiti Department of Ocean Engineering Indian Institute of Technology MadrasChennai 600036India West Bengal State Fisheries Development Corporation Limited Kolkata 700091India

The Sagar Island,located north of the Bay of Bengal,intercepts the flow in the Hoogly estuary that comprises a network of several estuarine distributaries and creeks,which is considered to be one of the largest estuarine systems in the *** Hooghly River experiences a tidal range in the order of about 4 m,due to which the tide-generated currents drive the sediments which are continuously set in *** temple,Kapil Muni(21°38'15.35"N,88°4'30.56"E)is located on the south-western side of Sagar Island,where an annual religious festival and rituals with about a million pilgrims is *** pertinent erosion problem at a rate of about 5 m/year is prevalent at the site has considerably reduced the beach width,thereby,resulting in reduced space for religious as well as recreational activities along the coast.A novel cross-section for the proposed submerged reef using geosynthetic materials is designed considering the different sitespecific,environmental,and socio-economic *** submerged reef can effectively be devised to redistribute the current circulation pattern and trap the sediment for beach *** performance of such a structure depends on its geometrical and structural characteristics,the location of the reef(i.e.)the water depth at the toe,distance from the coastline,wave-structure interaction,sediment transport and local morpho *** aforesaid criteria were optimized using a numerical model which predicted the average residual velocity in the site to be in the order of about 1 m/*** to logistical constraints geosynthetic materials had to be *** detailed design of such a system arrived through numerical modelling and field measurements are presented and discussed in this paper.

关键词： Island coastal erosion Submerged reef Tide dominant currents sediment movement Geosynthetic materials

PROGRESS OF sedimentATION RESEARCH FOR THE YANGTZE RIVER

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PROGRESS OF SEDIMENTATION RESEARCH FOR THE YANGTZE RIVER