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Muin, M. and Muslim, A.B., 2023. Anak Krakatau Landslide Tsunami and sediment transport simulation using non-orthogonal boundary fitted technique in spherical coordinate model. In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 146-150. Charlotte (North Carolina), ISSN 0749-0208. This paper presents a simulation of a tsunami induced by the Anak Krakatau Landslide in Indonesia and the sediment dispersion transported by the tsunami. The hydrodynamic model of this simulation used a non-orthogonal curvilinear technique in Spherical Coordinates and was developed in GIS on Windows System, named MuTsunami. The advantages of MuTsunami are rapid computation, accurately solving complex geometry, and integrating with the sediment transport model. This software is suitable for an early warning system. MuTsunami has also been applied in the 2010 Mentawai and 2004 Aceh Tsunami. The results show good agreement with the observation data. The simulation results indicate that the tsunami reached Serang, Ciwandan, Kota-Angung, and Panjang within 1860, 2760, 2100, and 4140 seconds after the Anak Krakatau Landslide occurred. The waves along the coast occurred up to 9 m and 8 m for Banten and Lampung coasts. The sediment transport result shows bathymetric changes along the Banten coast 30 minutes after the landslide. The required time to simulate the tsunami from the Anak Krakatau Landslide is only 15 seconds which is suitable for an early warning system. [ABSTRACT FROM AUTHOR]

Fitria, J.; Gemilang, R.I.A.; Purnama, B., and Prasetyo, A., 2023. Rapid changes in the coastal morphology of Amurang, North Sulawesi, Indonesia. In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 289-293. Charlotte (North Carolina), ISSN 0749-0208. Changes in coastal morphology can occur through long-term processes, such as sediment transport, and through short-term processes, such as those caused by earthquakes, storms, or tsunamis. On June 15th, 2022, a rapid change in coastal morphology due to a landslide happened in the coastal area of Amurang, North Sulawesi, Indonesia. Morphological changes and their triggers were analyzed through a comparison of post-slide and preslide bathymetry data, satellite imagery, and analysis of the soil layers. Based on the comparison of bathymetry data, the maximum change in seabed depth in the landslide area was 51 meters with a curvature shape on the rupture surface. The coastline has retreated about 150 meters inland with around 2.34 million m3 of material displaced. The results show that the landslides on the Amurang Coast that caused the rapid morphological change in the area were not triggered by hydro-oceanographical conditions, tectonic events, or volcanic events. They were triggered principally by the over-steepened slope and the ground soil's ability to support the additional weight of building embankments over a thick sediment layer. [ABSTRACT FROM AUTHOR]

Hwang, B.-H.; Do, K.-D., and Chang, S.-Y., 2023. Morphological response of Storm Hinnamnor at Songjeong Beach using UAV-derived data. In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 126-130. Charlotte (North Carolina), ISSN 0749-0208. This study investigated the morphological response of a wave-dominated beach to large storms via field data collection. The field data were collected on Songjeong beach facing SE in the south-eastern corner of Korea. This study measured pre- and post-storm beach volumes by Storm Hinnamnor using Unmanned Aerial Vehicle (UAV). In this storm event, the peak of the significant wave was 10 m, and the wave period mainly varied between 10.9s under stormy conditions. The incident waves were mostly easterly at 90-115.5°. During this event, due to the strong storm intensity, the upper part of the sediment showed significant erosion along the entire beach, and net accumulation took place in the revetment area by overwash. The highest substantial loss occurred in the SW section of the study area, associated with the wave direction. Compared to the SW section, the mid and NE section of the study area eroded sediment. It was transported to the upper beach near the revetment area, suggesting that the onshore sediment transported was dominated in this area. After the storm, the local government undertook beach nourishment to restore the deposition sand on the revetment to the beach. This study carried out the UAV survey after beach nourishment and estimated the sediment volume by overwash. As a result, it was estimated that the amount of sand transported to the offshore area was 9533 m3, and the overwash deposition volume was 1441.3 m3. This study shows that UAV surveys can effectively estimate the morphological response of storm on the beach. [ABSTRACT FROM AUTHOR]

Li, H.; Beck, T.M.; Moritz, H.R.; Groth, K.; Puckette, T.; Marsh, J., and Sánchez, A., 2019. Sediment tracer tracking and numerical modeling at Coos Bay inlet, Oregon. Journal of Coastal Research, 35(1), 4–25. Coconut Creek (Florida), ISSN 0749-0208. An investigation was conducted on transport of dredged material placed in the nearshore area of an ocean dredged material disposal site (ODMDS) adjacent to the Coos Bay inlet, Oregon. A sediment tracer release/sampling and field data collection program was carried out and a numerical hydrodynamic, wave, and sediment transport model, the Coastal Modeling System, was developed to perform the analysis of sediment transport around the inlet system and the ODMDS. The data were used to calibrate and validate model calculations, and the model was set up to calculate sediment fluxes and to simulate the process of sediment tracer release and movement, and determine the pathways of sediment tracer under combined wave, current, and wind conditions within and around the immediate vicinity of the Coos Bay ODMDS. The calculations and the measurements indicate that sediment tracer movement is primarily controlled by tidal current inside Coos Bay and at the inlet entrance, and responding to wave and storm conditions in the open coastal area. A divergence in net sediment transport directions in the adjacent nearshore beach was apparent in the results of the tracer release and numerical simulations. This methodology may be used to determine sediment bypassing pathways and optimal placement of sediment within a nearshore environment adjacent to tidal inlets. [ABSTRACT FROM AUTHOR]

ABSTRACT Solari, S.; Alonso, R., and Teixeira, L., 2018. Analysis of Coastal Vulnerability Along the Uruguayan Coasts. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1536–1540. Coconut Creek (Florida), ISSN 0749-0208. The objective of this work is to identify the most vulnerable areas to coastal erosion on the Uruguayan coast. To this end, global wind and local waves and sea level reanalysis were used to estimate the littoral and aeolian sand transport rates (cross- and long-shore), the response of the beach profile to extreme events (by means of X-Beach model) and the supply of sand from rivers all along the Uruguayan coast, obtaining 18 years of three-hourly data. For each estimated variable, its intra- and inter-annual variability and its correlation with relevant climatic indexes were calculated. Using this information the sediment budget of the coast was analyzed at different scales: global (all the Uruguayan coast; O(100 km)), regional (physiographic units, O(10km)) and local (beach nodes; O(1km)). In turn, the above information was combined with a qualitative assessment of the coastal uses, obtaining a vulnerability index used to identify priority areas to undertake detailed studies. [ABSTRACT FROM AUTHOR]

ABSTRACT Shim, W.J. and Kim, C.W., 2018. The necessity of coastal management in Busan Considering human and natural conditions: The case of barrier islands in Nakdong-estuary. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp.1501–1505. Coconut Creek (Florida), ISSN 0749-0208. The Busan coasts have complex natural and human conditions including dynamic coastal, river processes and human activities. These complex natural and human factors have had direct and indirect impacts on the coastal areas of Busan, so a spatially integrated approach for management is required. Especially, the barrier islands located in the Nakdong River estuary are proper examples that show the effect of the sediment budget as natural and human conditions. This research aims to identify the effects of natural and human conditions on the barrier islands. The area of the barrier islands, sediment budget from the watershed, the amount of dredging at Nakdong-Estuarine-Dam and land use coverage were compared using correlation analysis. The more sediment eroded from watershed and the less sediment was dredged at Nakdong-Estuarine-Dam, the larger area of the barrier islands. This indicates that boundary conditions such as the supply of sediment from the rivers are related to the barrier islands; thus river and watershed management are important. Regarding land use, used and barren areas are positively correlated with the barrier islands, but water, forests and agricultural lands are negatively correlated. Internal factors within Busan, such as coastal modifications and urban growth, are affecting coastal dynamics, which change the sediment budget. These results show that the barrier islands sensitively respond to boundary conditions from the river and watershed and to internal conditions such as shoreline management and development. Therefore, for the effective management of Busan's coasts, it is necessary to consider how natural and human conditions interact spatially. [ABSTRACT FROM AUTHOR]

Ferreira, C.; Silva, P.A.; Fernández-Fernández, S.; Baptista, P.; Abreu, T.; Romão, S.; Fontán-Bouzas, A.; Bertin, X., and Garrido, C. 2018. Wave Climate Definition on Modeling Morphological Changes in Figueira da Foz Coastal System (W Portugal). In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp.1256–1260. Coconut Creek (Florida), ISSN 0749-0208. Field surveys at Figueira da Foz coastal system, a jettied river-mouth located to the W of Portugal, show a high impact of storm events on the morphological evolution of the ebb-tidal delta, with formation of a submerged sandbar and the quick infill of dredged areas. Non-stormy wave conditions produce minor morphological changes. The morphodynamic modeling of this system is being done to support coastal management. The methodology uses Delft3D modeling system that was previously calibrated for this coastal region. Modeling scenarios are set by considering two initial bathymetric situations, i.e., with or without an excavation site resulting from dredging operation. In order to investigate the relations between the computational efficiency and the time series of the input wave data, some tests were performed including a month with a total of 70% of storms and other with 10%, approximately. For each period it was studied the whole month period and only the storms. Numerical results disclose similar patterns of morphological evolution for both complete and storm periods simulated. Nevertheless, the omission of lower wave energy conditions slightly covers up the volume of sediment accretion in the area. This volume of sediment accretion masking effect is higher in the dredging case study, since dredged area acts as a sink of sediment. The results demonstrated that morphodynamic simulations should include the whole set of waves recorded to achieve more accurate estimations of sediment transport rates and corresponding sediment balance. [ABSTRACT FROM AUTHOR]

Kim, H.-C.; Song, Y.-S.; Kim, Y.H.; Son, S.; Cho, J.-G.; Chang, W.K.; Lee, C.-H.; Nam, J., and Ryu, J., 2018. Implications of esuarine and coastal management in the growth of Porphyra sp. in the Geum River Estuary, South Korea: A modeling study. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 396–400. Coconut Creek (Florida), ISSN 0749-0208. Laver (Porphyra sp.) is one of macroalgae species that has been cultivated for the purpose of food consumption in the coastal areas of Korean Peninsula. In specific, Porphyra tenera Kjellman and Porphyra yezonensis Ueda are two major commercial species for aquaculture in the west coast of Korea. In this study authors employed an ecosystem modeling approach (Hadley et al., 2014) to simulate the nutrient physiology and growth of the laver in aquaculture facilities located in the vicinities of Geum River Estuary. Some of model coefficients and parameterizations were modified from the original version based on laboratory experiments, if necessary. In addition, authors calibrated and validated the Delft3D (https://oss.deltares.nl/web/delft3d) with long-term time series data from the area. The Delft3D is an open source modeling suite that can simulate hydrodynamics (temperature, salinity, flow fields), sediment transport and water quality variables (inorganic nutrients). As one of the end-point goals of the present study is to develop decision supporting tools that can be used by coastal managers, the macroalgae growth model was coupled with the Delft3D in order to predict effects of episodic climatic events and/or upstream water management decisions on the estuarine ecosystem. Temperature, salinity and nitrogen loadings estimated from the Delft3D were used as input to the ecosystem model, and subsequent responses from Porphyra sp. were numerically simulated. Given thirteen scenario-based simulations, it is found that model simulated dissolved inorganic nitrogen concentrations do not change significantly for the same climatic condition. However, the maximum potential annual production of macroalgae is found to be more dependent on ammonium ion concentration. [ABSTRACT FROM AUTHOR]

Kim, H.-J.; Suh, S.-W.; Seok, J.-S., and Park, W.-K., 2017. Sedimentation for a flood-dominant estuarine harbor induced by anthropogenic activities. In: Lee, J.L.; Griffiths, T.; Lotan, A.; Suh, K.-S., and Lee, J. (eds.), The 2nd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 79, pp. 339-343. Coconut Creek (Florida), ISSN 0749-0208. Sedimentation around the Kunjang harbor area in Korea has intensified at a rate of ~2.0 m/yr because of the construction of an estuarine dam in 1988, which resulted in the tidal energy being blocked and the development of a flood-dominant environment. The construction of several harbor facilities cumulatively altered the tidal hydrodynamics and yielded sedimentation. Moreover, the annual maintenance dredging for the main channel accelerated alteration. In order to understand the sedimentation characteristics, archived intensive depth measurements were used to assess the variations in the bottom shear stress. Our results showed that the bottom shear stress and tidal prism have lessened. The resulting sedimentation should be managed through dredging or minimization plans based on an appropriate engineering solution. In this paper, we suggest an optimized weighting factor to represent diverse physical morphological variations that affect the shear stress. It can be used to compensate for unsatisfactory results generated by a morphological model. Our findings can help in devising an efficient engineering approach to mitigate sedimentation for a flood-dominant estuarine harbor. [ABSTRACT FROM AUTHOR]

Postacchini, M.; Russo, A.; Carniel, S., and Brocchini, M., 2016. Assessing the hydro-morphodynamic response of a beach protected by detached, impermeable, submerged breakwaters: A numerical approach. Coastal areas host a large fraction of the world's population and are exposed to natural extreme events, which are a serious threat to human life, as well as to economies. For this reason, sea storms are increasingly the object of studies, and the design of traditional coastal defenses is being carried out in conjunction with modeling analyses. Relying on numerical simulations performed by means of an innovative shallow-water hydro-morphodynamic model, the present work explores the overall response of a protected beach to sea storms. Numerical tests evaluate the effects of sea states extracted from realistic sea storms having different spectral characteristics, as well as the influence on beach morphology of positioning shore-parallel, impermeable, submerged breakwaters. Simulation results revealed that, while erosion/accretion patterns depend weakly on the different sea state conditions, the morphodynamics induced around the barriers is strongly influenced by the breakwaters' positioning. More specifically, at least for the forcing here analyzed, bed variations were shown to increase when the structures are progressively located offshore; on the other hand, the swash zone morphology seems to be only weakly influenced by the positioning of the breakwaters. We also observed that for an increasing extension of the volume over which dissipative breaking mechanisms occur, a decreasing inshore erosion is accompanied by an equally fast decrease of offshore erosion. Analysis of the vorticity fields shows that breakwaters placed far from the shoreline induce an evolution of the vortices generated by breaking waves rather different from the one due to breakwaters placed closer to the shoreline (which can induce seaward flows through the gap, like rip currents). [ABSTRACT FROM AUTHOR]

De Jong, B.; Keijsers, J.G.S.; Riksen, M.J.P.M.; Krol, J., and Slim, P.A., 2014. Soft engineering vs. a dynamic approach in coastal dune management: a case study on the North Sea barrier island of Ameland, The Netherlands. Dunes act as flood defenses in coastal zones, protecting low-lying interior lands from flooding. To ensure coastal safety, insight is needed on how dunes develop under different types of management. The current study focuses on two types of coastal dune management: (1) a 'soft engineering' approach, in which sand fences are placed on the seaward side of foredunes, and (2) 'dynamic coastal management,' with minimal or no dune maintenance. The effects of these management styles on dune formation are examined for two adjacent coastal sections of the North Sea barrier island of Ameland, The Netherlands, where dynamic coastal management was introduced in 1995 and 1999, respectively. For each section, we analyzed cross-shore profile data from 1980 until 2010, deriving dune foot position, crest position, crest height, and foredune volume for each year and analyzing the situation before and after the change in management. We further assessed the effect of the management regime on dune vegetation. Other factors that could influence dune development were also taken into account, such as beach width and shape, water levels, wave heights, and nourishments. Results show that implementation of dynamic coastal management did not directly affect the volume of the foredune. Growth was occasionally interrupted, coinciding with high-water events. In periods between erosive storms, dune growth rates did not show a significant difference between management types ( p = 0.09 and 0.32 for sections 1 and 2, respectively). The main effect of the change was on vegetation development. Dynamic coastal management, therefore, did not reduce coastal safety. [ABSTRACT FROM AUTHOR]

McLaren, P., 2014. Sediment trend analysis (STA®): kinematic vs. dynamic modeling. The number of techniques commonly used to determine sediment transport (its erosion, movement, and deposition) is limited. They include geomorphological observations, tracers, in situ measurements, and numerical modeling, each of which has various practical difficulties or a necessity for assumptions that may be inadequate or incorrect. Another approach, using the relative changes in grain-size distributions to derive the net sediment-transport patterns and sediment behavior, has become increasingly common, and a number of methods applying its theory has been developed. This article concerns itself principally with the technique, developed by the author, known as Sediment Trend Analysis (STA). Unlike a dynamic model in which processes resulting in sediment transport must be assumed, STA is a kinematic model, whereby the behavior of sediment particles is described without regard to the process. Kinematic modeling is, in comparison to dynamic modeling, simple to do and, in many practical situations, may supply sufficient information for most sediment management issues. If not, however, it is suggested that a kinematic model is a necessary prerequisite to assess the most-effective methods for obtaining quantitative information, including directing and validating the more-complex techniques of dynamic modeling. [ABSTRACT FROM AUTHOR]

Costa, S. and Coelho, C., 2013. Northwest coast of Portugal Past - behavior and future coastal defense options Portugal's northwest coast, between Ovar and Marinha Grande presents an important sediment deficit, mainly due to rivers sediments supply reduction and harbors' constrains. The sediment transport capacity resulting from the wave's action (mainly from the northwest) is nourished with the sand of the up drift beaches, leading to the shoreline's erosion and retreat. The shoreline retreat represents conflicts with the land use and human occupation, and the protection of people and properties becomes essential. Thus, coastal interventions (seawalls and groins), try to constrain the shoreline evolution, conducting to an artificial coast and site aesthetical deterioration. This work's objective is to present an analysis of the shoreline evolution, in order to select a suitable model of coastal intervention. Thus, the current paper aimed a diagnostic based in the shoreline evolution indicators in the period between 1994-2011: a) average rate of shoreline retreat; b) number of coastal defense structures implemented; c) number of coastal emergency works and interventions; and d) number of registered events related to shoreline retreat (overtopping, dune system and coastal structures partial destruction). This analysis highlights the location of the most vulnerable areas. Furthermore, different scenarios of coastal defense interventions are discussed, having as variable the associated investment costs, which represents different strategies and impacts, namely: a) maintain the existent coastal defense structures; b) adapt the existent coastal defense structures; c) perform artificial nourishments; and d) propose new coastal defense solutions. [ABSTRACT FROM AUTHOR]

Rahman, S., Mano, A. and Udo, K., 2013. Quasi-2D Sediment Transport Model Combined with Bagnold-type Bed Load Transport. Suspended load and bed load sediment transport are important component for the sediment transport in surf zone. The purpose of this study is to obtain a good model for sediment transport in surf zone by combining a quasi-2D sediment transport model and the Bagnold-type sediment transport model. The quasi-2D sediment transport model is used to simulate the suspended load transport, while the Bagnold-type for the bedload transport. A quasi-2D numerical wave model called Funwave was expanded to accommodate the sediment transport model. The model is validated by the published data for sediment transport in a wave flume. Two mode of morphological change is compared to evaluate the influence of wave-current (mode A) and instantaneous bottom velocity (mode B) in the third and forth velocity moment of Bagnold-type sediment transport model. Four sets of bed load transport parameters are evaluated to calculate bed level change. The evaluation shows that although e B exceeds one, it can produce bed level change similar to that by using the parameters proposed by Bailard. Parameters proposed by van der Molen calculated very high bed level change, while Gallagher's parameter produced relatively small bed level change. The performance of two modes of morphological change shows that mode A produce much better morphological change than mode B in surf zone for the bedload transport component. While for the suspended load component, mode B produces very high erosion in surf zone. Coupling of mode B and a wave motion-induced suspended load transport gives comparable morphological change to the experimental data. [ABSTRACT FROM AUTHOR]

Lee, H.S., Kim, I.H., Song, D.S. and Lee, J.L., 2013. A Correlation Analysis between a Swim Zone Width and Beach Survey Data in Sokcho Beach Sokcho Beach is the 3 km-long sand beach located on the east coast of South Korea. Beach profile surveying and grain size sampling in four control sections were carried out in order to investigate the relationships of swim zone width between the median size, beach face slope, and scale factor. It is found that temporal variation in the southern part of beach is the most severe due to the presence of Oeongchi headland. As the result of the correlation analysis, the correlation factor of the swim zone width to the scale factor was estimated rather high (0.596). The present study shows the grains size is not an adequate indicator in estimating the swim zone width. Regular monitoring of the region is required to determine the seasonal changes, the sediment transport, and the changes in the sedimentation environment, and to acquire an accurate understanding of the beach environment and of the changes that it is undergoing. [ABSTRACT FROM AUTHOR]

This contribution is part of the Gulf Regional Sediment Management Master Plan and serves as a broad overview of the general setting, geologic history, coastal processes, hydrodynamics, and sediment sources for the Gulf of Mexico (GOM). The GOM is approximately 1,500,000 km2. The five U.S. states bordering the Gulf comprise over 75,000 km of coastline. Gulf circulation is dominated by the Loop Current and gyres. The general trend of longshore sediment transport is in the westward direction west of the Mississippi River and in the eastward direction east of the Mississippi River, and is driven primarily by the wave and tidal energy. The GOM is a shallow basin and its climate is strongly dependent on precipitation and temperature averages. The general coastal climate is subtropical with warm to hot summers and cool winters with precipitation and high relative humidity throughout the year. The GOM coast is predominantly microtidal (<2-m range) with coastal processes and associated morphodynamics strongly influenced by storms. Tropical cyclones have affected every GOM coastal county or parish since 1900. Over 150 rivers flow into the Gulf; 85% of the fluvial water contribution is from U.S. rivers and of that, 64% is from the Mississippi River, which discharges approximately 2.4 billion kg of sediment annually. Humans are altering the natural coastal sediment budget through beach nourishment and dredging that affects the beach-dune sediment exchange. Six of the 10 most socioeconomically vulnerable coastal counties in the United States are in the Gulf region, which emphasizes the need for a sediment management master plan. [ABSTRACT FROM AUTHOR]

Spit growth is observed across many rivers of the central west coast of India. Studies on the seasonal dynamics of the spits of the central west coast of India on the basis of the multidate satellite images LISS III, landsatTM data, panchromatic camera (PAN) data etc. in a geographic information system (GIS) environment using ERDAS imagine 9.0 version followed by field-check and wave data analysis have been discussed in this paper. All types of spits such as paired spits, winglike spits, single spits, etc. are observed along the coast of Karnataka, central west coast of India. Spit growth is responsible not only for shifting of the river mouths, but also for rapid changes in estuarine morphology and in turn on the sedimentation process. It is observed that river mouths with a spit across them have a submerged bar in front of them, whereas rivers devoid of spits are also devoid of submerged bars in front of them. This spatial association of spit and submerged bar is believed to have a genetic relationship. Along the coast many perpendicular faults and uplifts have been observed. Rate of spit growth, along with their direction and inland drainage pattern, suggest a role of sea-level changes and tectonic control in addition to alongshore currents. Rapid spit growth is observed near the inferred tectonic axis. Seasonal dynamics and modification in the spit configuration are related to alongshore drift as well as the wave refraction around the mouth of the rivers. [ABSTRACT FROM AUTHOR]

In the Portuguese southern coast, national and international appeal turns it into a highly relevant area concerning the country's economy. Vale do Lobo is a resort located in the centre of this coast, where the beach has been suffering from erosion problems for several years now. Local interventions have been executed in order to prevent the erosion of the beach, yet the efficiency of such strategy has not been verified. This study's main purpose is to enable a better understanding of the evolutionary trends of the coastline between the Quarteira and Ancão inlet and to analyse the efficiency of the beach nourishment interventions as a protection technique for a coastal environment with the wave energy exposure and geomorphologic characteristics of the present one. The study focussed on a 10-year period, during which, 700x10³ and 370x10³ m³ of sand with D50=0.76 mm (slightly larger than the D50 of the native beach) were extracted from offshore, and deposited in the foreshore. The wave climate in the study area was processed, analysed and used as input for modelling the nearshore processes. In addition, beach profiles measured alongshore have been analysed to obtain the representative beach profile. Coastlines of different dates have been derived from aerial photographs. The longshore transport model Litdrift and the coastline model Litline were applied to study the sediment dynamics. Litdrift was used to estimate the longshore transport capacity of the beach for the hydrodynamic series considering the representative beach profile previously obtained. These results were then used to calculate the evolution of the coastline due to the incident wave climate with Litline model. Aerial photographs were used to verify the model. The analysis of the two beach nourishments performed allowed inference on the efficiency of this coastal protection technique to delay the erosion process. [ABSTRACT FROM AUTHOR]

Because of the special geographic features and high rate of biological productivity of the estuary, analyzing the evolution of an estuary over long periods is important for understanding and predicting environmental changes in the natural ecosystem. To predict the behavior of the varied flow conditions in natural phenomena, we require a simple mathematical model to analyze that behavior. Averaging methods are extensively used for fluid studies. Based on changing flow conditions, the time span could be divided into three periods, long, medium, and short. In this paper, a long-term averaging model for the estuary is introduced to predict flow variation, sediment transport, and bed morphology change. In addition, various variables that may influence the river system are discussed, and some reasonable values of these variables are estimated empirically. By introducing the time scales and instantaneous variables into the one-dimensional hydraulic equations of continuity, momentum, sediment transport, and bed morphology change, we obtain four simplified equations. A case study of the Snowy River is discussed. Based on these simplified dynamic equations, we identify four attractors by solving the equations numerically under certain boundary conditions. [ABSTRACT FROM AUTHOR]

Study of suspended sediment transport in an estuary affected by tidal bore is important for coastal engineering and management because the tidal bore can cause strong sediment resuspension and scour in shallow waters. Numerical modeling of suspended sediment transport in a natural estuary affected by tidal bore is such a challenging research topic that there are few articles on the subject available in the literature. In this study, a two-dimensional, numerical model was developed to investigate suspended sediment transport induced by a tidal bore. The hydrodynamic component of the model employs the Godunov-type scheme with second-order accuracy in space, which effectively describes the rapid supercritical flow and sharp horizontal pressure gradients of the tidal bore. To preserve balance between the source terms and the internal forces, both the water level-bottom topography formulation (WLTF) method and a special technique for triangular mesh have been applied to solve the source term in the model equations to account for the irregular bottom topography. The wet/dry boundary issue was solved by using the improved exact-Riemann solver on the dry bed. The coupled sediment transport model incorporates more reliable equations from recent publications to characterize the rapid increase of sediment resuspension in the water column. The model test against an analytical solution of convection transport shows that the sharp gradient of scalar transport is satisfactorily estimated in the model simulations. The model in the application has been validated to simulate hydrodynamics and suspended sediment transport affected by a tidal bore in the Qiantang River of China. The results compare well with a time series of observations to characterize the rapid increases of surface elevation, currents, and suspended sediment concentration resulting from the tidal bore. Results of spatial distributions of water levels and currents indicate that the model adequately describes the sharp horizontal gradients of the surface elevation and the tidal currents during the passage of the tidal bore and characterizes the suspended concentrations in the estuary. [ABSTRACT FROM AUTHOR]

Overwash induced by storms is one of the factors that threaten coastlines, causing erosion and sediment transport, especially in areas of low dune elevation. Laboratory experiments provide mechanisms for eliminating many of the varied environmental conditions that typically exist in the field. For instance, it is difficult to observe conditions before and after the landfall of a storm; however, such observations are much simpler in a laboratory setting. The experiments conducted in this study focused on the volume of eroded and transported sediment by overwash of the berm and dune at different slopes, the wave heights, and the periods of regular and irregular waves. Experiments were conducted under both short-term (327 s) and longer-term conditions (30, 60, and 180 min). The newly developed zero-point method that calculates the offshore and onshore sediment transport was used for analysis and was verified with field measurements. The empirical equations were developed using robust regression after selecting dominant factors in a sensitivity analysis. The regression equations compared favorably with the laboratory and field data. The empirical equation for irregular waves proved to be a simple and quick way to estimate the landward sediment transport rate by overwash. [ABSTRACT FROM AUTHOR]

The behaviour of sediment fluxes is currently less well understood in the inner-surf and swash zones than farther seaward. In the present study, field measurements were obtained of cross-shore velocity and suspended-sediment concentration from 6 and 13 heights above the bed, respectively, between the breakpoint and the shore of an intermediate- to-reflective beach, over a range of hydrodynamic conditions, to examine the cross-shore structure of sediment flux and the physical mechanisms responsible for the observed patterns. Particular attention is given to the innersurf and swash zones, which are known to contain sediment-transport processes poorly predicted by models based on velocity moments. The cross-shore structure of the depth-integrated, suspended sediment flux is found to vary according to the forcing conditions considerably more in the inner-surf and swash zones than in the outer surf and shoaling zones. In high-energy conditions, fluxes are dominated by a large offshore peak in the outer swash zone, and in low-energy conditions, fluxes are dominated by weak onshore values increasing shorewards. Examination of the temporal and vertical structure of the velocity, sediment concentration, and flux within individual events where offshore transport was dominant reveals that near-bed suspended sediment responds just as readily to mid-watercolumn velocity shear as to boundary-layer shear. Examination of events in which onshore transport was dominant reveals that near-bed suspended-sediment concentration responds more readily to near-bed horizontal acceleration than to absolute values of near-bed velocity. [ABSTRACT FROM AUTHOR]

Quantification of the sediment transport processes in the Fort Pierce Inlet, Florida area and the influence of the inlet onto the adjacent beaches was performed by means of analytical methods. This analysis is formalized as a sediment budget and is based on available survey data, nourishment events, and dredging records of the navigational channel at Fort Pierce Inlet, which cover the period from 1972 to 2002. Available survey data encompass shoreline distances approximately 9.7 km north and 24.7 km south of Fort Pierce Inlet. Three intersurvey periods were examined in this study: 1972 to 1987, 1987 to 1997, and 1997 to 2002. Average annual sediment volume and shoreline changes derived from the profile data collected during these three periods were analyzed. Application of general sediment budget principles established that for the total period from 1972 to 2002, there was an average annual deficit of approximately 12,500 m3/y on the beach south (downdrift) of Fort Pierce Inlet. The general sediment budget suggests that 88,700 m3/y enter the north boundary of Riomar Beach some 18 km north of the inlet; 62,700 m3/y enter the north boundary of St. Lucie County some 10 km north of the inlet; and 43,600 m3/y leave the south boundary of St. Lucie County some 25 km south of the inlet. Application of numerical modeling to develop an understanding and predictability of the performance of beach nourishment south of the inlet was carried out as a supporting method to better understand the littoral processes in the area. Recommendations to improve the sediment management practices, including sand bypassing to restore balance to the south beaches, are presented. [ABSTRACT FROM AUTHOR]

Lee, J.L. and Cho, Y.-J., 2021. Numerical analysis of sediment transport rates from rip currents at an open inlet between Low Crested Breakwaters (LCB): The role of infra-gravity waves. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 489–493. Coconut Creek (Florida), ISSN 0749-0208. Low Crested Breakwaters (LCB), the most preferred structural type in the coastal zone management project by the Korean Ministry of Ocean and Fisheries, has been designed to mitigate beach erosion by high waves occurring only a few times a year. Now that moderate sea conditions are dramatically different from those in rough seas, these poor design practices could interrupt the grand circulation process of natural beaches over the course of a year. As a result, the beach stabilizing effect of LCB often falls short of our expectations. In this study, in order to test this hypothesis, 3-D numerical simulation was carried out to analyze the rip currents and its associated sediment transport at the open inlet between LCB when LCB is subject to infra-gravity waves, which play an indispensable role in the beach restoring process in a mild sea with an annual prevalence rate of over 80%. Numerical results show that in the case of LCB with lower crest freeboard, rip currents gets increased by 2.6 times when compared to the one before the deployment of LCB since the water mass influx toward the down-wave side of LCB by overflowing LCB by the preceding waves is redirected toward the open inlet. The sediment transport rate was estimated using Bailard's model, the most referred cross-shore sediment model in the literature. It was shown that the primary sediment transport mode at the open inlet between LCB was bed load, and sand of 5.62 ×10–5m3 / m was leaving the inner zone of LCB per unit wave period. [ABSTRACT FROM AUTHOR]

Yoo, H.J.; Kim, D.H.; Park, M.H., and Lee, S.O., 2021. Economic sediment transport control with sediment flushing curves for sea dike gate operation: Case study in Saemangeum Basin, Korea. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 161–165. Coconut Creek (Florida), ISSN 0749-0208. As the major reclamation works in Korea, the sea dikes have been installed for preventing the saltwater intrusion in Saemangeum Basin connected with Mangyeonggang and Dongjingang River, Korea since 2010. Recently, the sedimentation issues near the gates due to change of flow velocity might induce serious problems such as water pollution, local scour, stability of hydraulic structures linked with dike. We focused that the gate operation rule was changed to alleviate the sediment transport problem by altering the management water surface elevation in this study. The 3D numerical model, SCHISM, was used to simulate the sediment transport under the gate operation rule which was embedded after modifying the hydraulics structure module in SCHISM. The numerical model was verified by comparing with the measured data in the literature. It was found that the phenomenon induced by gate operation was accurately simulated to compare with the field measurements from Korea Rural Community Corporation (KRCC). Based on the results of SCHISM, the Best Management Practices on gate operation were examined and suggested the optimal solution in terms of structural stability and water use including water quality. [ABSTRACT FROM AUTHOR]

During Hurricane Ivan (2004), dunes in undeveloped sections of northwest Florida were significantly reduced in height through direct wave erosion and the transfer of sediment to the backbarrier by overwash. The poststorm morphology of the island consists of a narrow beach face, multiple breach corridors, a washover terrace, and a remnant secondary dune that was further eroded in 2005 by Tropical Storm Arlene and Hurricanes Dennis and Katrina. The redevelopment of this dune will direct the response of the island to future storms, but the mechanisms of posthurricane dune recovery are unclear, particularly in this low-energy coastal environment. The recovery is further complicated by a swale that was created through a knickpoint effect on an adjacent road. The swale was reinforced when the road surface was removed and as a berm developed during the recovery of the beach face. Field observations suggest that sediment transport across the narrow beach face and berm is limited by a lag of shells and gravel from the pre-Ivan roadbed. As a consequence, sediment input to the dune is relatively minor with onshore winds, despite the presence of fans deposited during frontal storms in the swale behind the berm. The resulting sediment transport gradient across the seaward slope of the dune is more reflective of the expanding fetch than topographic acceleration and the drag imposed by the sparse vegetation. In contrast, there is a larger sediment input to the dune during offshore winds in response to the larger fetch across the washover terrace, despite the presence of a lag. It is concluded that posthurricane dune recovery in this area is strongly dependent on the deposition of sediment during frontal storms and the resulting development of a sand ramp through the swale. This will increase both the availability of sediment and the fetch for winds directly or obliquely onshore. [ABSTRACT FROM AUTHOR]

The monitoring of existing coastal protection work and comparing the actual performance with the predicted one is one of the methods for developing coastal engineering processes. A comprehensible example, which clearly demonstrates the value of this monitoring process, could be found in the coastal protection works of El Agami resort area, Egypt. A group of seven detached breakwaters were constructed in front of the study area aiming to improve the beach condition with consideration for swimming capability. This is in addition to a temporary harbor to facilitate execution of the breakwaters. Deposition of seagrass and an undesirable temporary harbor are part of the coastal area problems. The implicit sediment transport two-dimension (ImSedTran-2D) numerical model, prototype data during the period from October 2002 to October 2003, and the empirical design relationships were used to study the environmental impact assessment of the breakwaters. Accordingly, a decision was made to eliminate the temporary harbor. The study area was observed to be quite stable, even with the detached breakwaters. This could be attributed to the orientation of the shoreline and its offshore submerged ridge, which extends parallel to the shoreline. Removing the harbor improves the ecosystem of the zone just behind the western breakwater by clearing out and stopping the deposition of the seagrass in this area with its negative effect on beach condition. The study area can be considered an ideal case because the empirical relationships, the prototype data, and the numerical model give more or less the same results. [ABSTRACT FROM AUTHOR]

Coastal erosion is an islandwide problem in Taiwan. On the basis of the result of the most recent survey, more than 80% of the island's sandy coasts have undergone erosion over the past 3 decades. Naturally and historically with the specific tectonic environment and uplifting rate in Taiwan, sufficient sediments had been yielded and transported to the coastal area, resulting in an advancing shoreline along the trailing edge coast during the last several centuries. However, human interventions have contributed significantly to the erosion in more recent times. In this paper, documented examples are chosen to address how human-induced changes have made profound impacts on the coastal erosion in Taiwan. The information presented will provide a better understanding of the coastal processes, and solutions to the erosion problem for the benefit of others in different parts of the world. [ABSTRACT FROM AUTHOR]

The Maspalomas dune field and adjacent beaches are the most extensive coastal sedimentary environment on the island of Gran Canaria. This area is very important from both a natural and an economic perspective. The analysis of aerial photographs and satellite images from recent decades does not show important shoreline changes for the El Inglés and Maspalomas beaches, which can be considered, consequently, in a state of equilibrium. However, the Maspalomas dune field presents several modifications, such as aeolian corridors associated with beach kiosks, a significant reduction in thickness of the aeolian deposits, and an increase of deflation areas in the underlying substratum. All these are proof of a drastic reduction in sediments. Sediment transport pathways obtained from the grain size parameters of beach samples show an input of sediments from El Inglés beach to Maspalomas dune field, whereas longshore drift is predominant on Maspalomas beach. This grain-scale analysis agrees with previous geomorphologic and wind studies. Foraminiferal content analysis also confirms the input of sediments from El Inglés beach to the dune field, as well as indicating the lack of inputs across Maspalomas beach, on which only seaward fluxes from closer dunes can be expected. Input and sinking areas of the system have been confirmed as well as a notable lack of sediments in the dune area, which is suffering severe erosion because of the shortage of sediment supplies from El Inglés beach. [ABSTRACT FROM AUTHOR]

A coherent approach to structuring reference units for coastal vulnerability analysis is often required for large-scale analyses of the coastal system. However, a review of existing spatial reference frameworks within vulnerability analyses demonstrates that our use of coastal space within large-scale models remains relatively poor. This paper examines a series of challenges to spatial modeling that have emerged from the development of a national to global impact tool, DIVA (Dynamic Interactive Vulnerability Assessment). The paper addresses how best to utilize the limited data to develop a reference framework for modeling vulnerability within the global coastal environment. It outlines the approach to spatial modeling that has been developed for use within the DIVA tool: segmenting the coastal zone into a series of relatively homogenous reference units at the scale of DIVA, based on the behavior of the physical, social, and economic systems within the zone. The importance of effective spatially defined models is emphasized within the paper. Encouraging greater spatial recognition and definition of the behavioral environment of the coast is critical to modeling space within the coastal system. By decreasing spatial uncertainties in the creation of reference units for vulnerability analysis, the accuracy of modeling within large-scale coastal environments can be further improved. [ABSTRACT FROM AUTHOR]

In 1997, the effects of severe erosion along the Penarth, Wales, UK, foreshore became apparent when the beach surface fell to critical levels. A 240 m length of beach, bounded by a slipway, sea wall, and pier, was surveyed each September and April between 1997 and 2002 to assess summer and winter changes Results in September 1997 showed that sediment transport was southerly in direction, whilst by September 2062, there had been a consistent return to the traditionally accepted south-to-north longshore drift, verified by significant differences in longshore gradients (t=2. 664; degrees of freedom [DF] =6; p < 0. 05). Analysis of changes in beach morphology has shown that erosion induced a southerly movement of beach contours, and a northerly movement was produced by accretion. Foreshore analysis has resulted in important regression models representing the variation of the shoreline indicator mean high water (MHW) with both shoreline position (mean beach level) and gain/loss of beach material The crossshore position of the depth of closure (DoC) was 50 m seaward of the survey line, at a water depth of 5. 5 m. Results from analyses of cross-shore profiles verified temporal variations in back beach level with little variation beyond the DoC. Furthermore, there was significant correlation between the two shoreline indicators, MHW and DoC (84%). This correlation, combined with a derived equation for a management response parameter (MRP = 17. 035 + tan-1 (x14- x6)/240[°]), produced simple tools to rapidly assess beach health. Results were compared with past data for interpretation of significance, and management strategies based on tabulated MRP values are suggested. A general {brm of this equation has been developed for testing at other beach locations, which should have significance from worldwide beach management. [ABSTRACT FROM AUTHOR]

The sediment budget of the Kızılırmak River has been disturbed during the last decade because of the flow regulation structures constructed on the river. This disruption has led to coastal erosion at the river mouth and its environs. With the effect of erosion within this period, the Black Sea shoreline has eroded approximately 1.0 km toward the Bafra Plain. In this study, the coastal erosion in the area was examined using physical and mathematical models. A shore protection structure system based on the results of the physical model tests was developed and implemented at the site. A one-line model was also applied for this part of the shoreline to study the problem mathematically. Analysis of the numerical simulation showed similar trends to the results of the physical model and field observation. The one-line model successfully represented the behavior of protection structures on the evaluation of the Kızılırmak River Mouth. One year after the completion of the protection structures, observations in the field showed that the erosion was completely controlled, and certain parts of the shoreline at this reach had advanced approximately 50 m toward the Black Sea. These protection structures have altered the longshore sediment transport along the shoreline of the Bafra Palin nearby the Kızılırmak River mouth. Therefore, the erosion at the ad.iacent shoreline of this reach has been accelerated at the expected level. [ABSTRACT FROM AUTHOR]

Aeolian sand transport on beaches and in dune environments shows a great spatial and temporal variability that has important implications for modeling and monitoring of coastal systems. Yet there have been few quantifications or statistical characteristics of transport variability in natural environments. Transport variability can result from bed surface control in the form of differentiation in grain size, surface moisture, and microtopography, or can be induced by fluid forcing in the form of gusts, burst-sweep events, and streamwise vortices. A field experiment was conducted on a coastal dune near Guadalupe, California, to quantify transport variability over spatial scales of 0.1–4.0 m and temporal scales of 1–120 seconds. Results show that spanwise (lateral) variability increases with spatial scale and decreases with temporal scale. Minimum transport variability over the smallest distances and longest time scales is on the order of 30%, providing error margins for transport-rate measurements and model extrapolations. Variability reaches a maximum level at spatial scales larger than roughly half the boundary-layer height. In relation to shear velocity, greatest variability is found near the transport threshold and smallest variability occurs during periods of high shear velocities. [ABSTRACT FROM AUTHOR]

Contemporary three-dimensional numerical sediment transport models are often computationally expensive because of their complexity and thus a compromise must be struck between accurately modeling sediment transport and the number of effective sediment grain (particle) size classes to represent in such a model. The Environmental Fluid Dynamics Code (EFDC) was used to simulate the experimental results of previous researchers who investigated sediment erosion and gradation around a 180° bend subject to transient flow. The EFDC model was first calibrated using the eight distinct particle size classes reported in the physical experiment to find the best erosion formulations to use. Once the best erosion formulations and parameters were ascertained, numerical simulations were carried out for each experimental run using a single effective particle size. Four techniques for evaluating the effective particle size were investigated. Each procedure yields comparable effective particle sizes within a factor of 1.5 of the others. Model results indicate that particle size as determined by the weighted critical shear velocity most faithfully reproduced the experimental results for erosion and deposition depths. Subsequently, model runs were conducted with different numbers of effective particle size classes to determine the optimal number that yields an accurate estimate for noncohesive sediment transport. Optimal, herein, means that numerical model results are reasonably representative of the experimental data with the fewest effective particle size classes used, thereby maximizing computational efficiency. Although modeling with more size classes can be equally accurate, results from this study indicate that using three effective particle size classes to estimate the distribution of sediment sizes is optimum. [ABSTRACT FROM AUTHOR]

The present paper, ‘Eb- en vloedschaarsystemen in de Nederlandse getijwateren’ (Ebb- and Flood-Channel Systems in the Dutch Tidal Waters), which was published in 1950, should be considered as Van Veen's most important publication since his thesis. It summarizes the results of 20 years of intensive study of estuarine and tidal-basin morphodynamics in The Netherlands. Unfortunately, Van Veen's paper was published in Dutch, with only a brief summary in English. Luckily, the figure captions were given in both Dutch and English, allowing international researchers coming across the paper to read it as a kind of ‘cartoon.’ Understandably though, the paper has received very limited recognition in the international literature. We have seized this occasion to publish an English version of Van Veen's paper. The paper is testimony to Van Veen's keen observational and artistic skills. His approach is nearly ‘Da Vincian,’ in the sense that he is not only a fascinated observer of nature, but a sharp one as well, and he tries to capture the essentials of the dynamic behavior of complex coastal systems in apparently simple sketches. Many of the natural systems that Van Veen studied have been regulated since; thus, this paper contains a set of irreplaceable, high-quality observations on the natural dynamics of tidal systems. It forms an excellent introduction to the study of channel dynamics in estuaries, tidal inlets, and tidal basins. [ABSTRACT FROM AUTHOR]

Tourism is the basic industry in Fuerteventura Island (Canary Islands, Spain), mostly due to the sunny conditions and excellent beaches. Probably the best well-known beaches are those located in the southeastern part of Jandía Peninsula, locally named Sotavento Beaches. These beaches are the largest and widest in the whole archipelago, and are up to 15 km long and 800 m wide in some points. Interest has focussed on these beaches not only from the tourism point of view, but also from a geomorphological perspective. Based on beach profile data and aerial photographs from 1963 until 1996 from the central part of these beaches, landward migration of the coastline has been identified. The width reduction of these beaches -to the point that in some areas the beach has completely disappeared- is a consequence of the reduction of sediment supply to the coast from inland sedimentary deposits. This reduction in sediment supply and consequent beach erosion is due to the development of tourism resorts and associated activities, such as road widening, sand mining and gardening along the roads. [ABSTRACT FROM AUTHOR]

In this study, firstly, the shoreline changes for various wave heights, wave periods and angles have been investigated on straight and curved beaches. The "One Line Model" of Hanson and Kraus which determines the shoreline changes by explicit finite difference numerical model, has been utilized. Subsequently, this numerical model has been applied to the shores of Altınova Town in Balıkesir, Turkey. Altınova has a valuable coastal zone that is located on the Aegean Sea with a coastline running more than 13 km and has a very high potential for tourism. It has been assumed that sediments are transported along the shore due only to the sea waves. In order to evaluate bathymetric changes and shoreline movement in the Altınova coast, hydrographic measurements were made in August 1996 and December 1997. In the nearshore region coastal erosion has clearly been predicted by comparison of numerical model results and data obtained by field measurements. Coastal structures have been suggested to protect against erosion. [ABSTRACT FROM AUTHOR]

An operational prediction system of suspended fine sediment transport has been established as a primary tool for coastal management. Various components of coastal models including coastal waves, tide, storm surge, and wave-induced circulation were taken into account for the accurate calculation of various processes involved in cohesive sediment transport especially during the extreme sea states. The system covers all coastal waters surrounding the Korean peninsula and for more detailed prediction of the near-shore area, a much finer grid model is nested to the whole area model. All models developed in this system were combined to allow easy testing and provide fast and accurate prediction. In this paper the results of a simulation test in the south-western coastal waters are shown and compared with field measurements. [ABSTRACT FROM AUTHOR]

At the site of a groyne construction a single profile line on the updrift side was repeatedly surveyed seven times at frequent intervals over 90 days when the groyne acted as an effective sediment trap. Over this time period the net accumulation was 839 m³/m, however variations in the incident wave energy gave sediment accumulation rates of some -0.1 m³/m to 7.4 m³/m per day. This variation of the sediment volume could be related to the incident breaking wave steepness for the periods pre; during and post construction. [ABSTRACT FROM AUTHOR]

Orviku, K.; Tõnisson, H., and Kont, A., 2020. Successful Management Practice Based on Studies of Shore Processes in Port Kunda, Northern Estonia. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 910–914. Coconut Creek (Florida), ISSN 0749-0208. Kunda is a small industrial town with a cement factory and a pulp mill on the northern coast of Estonia. There was an urgent need for a new port in Kunda at the beginning of the 1990s. The old port, constructed in 1805, stopped operating in 1940 and remained unused until 1994. The process of creating a new port started with discussions on selecting an appropriate site. The key tasks were: (1) not to disturb the functioning of the ecosystems; (2) to avoid clogging the outlet of River Kunda and (3) to prevent erosion of the adjacent sandy beach - a popular vacation site. River Kunda is an excellent spawning ground for valuable fish species. The scientists were facing a serious challenge on how to locate and build the new port so as to control the sediment movement in the area. A stony shoal opposite the old river mouth was a sedimentation trap favouring the siltation of the river outlet in the past. To prevent that process, the riverbed had been shifted a few hundred meters west some decades earlier. Maps and plans from different times were used and instrumental surveys were performed during the preparatory stage. Negotiations were held with different stakeholders until the right place was finally determined. After constructing the port, a monitoring programme was launched to reveal possible undesirable effects. 25 year later, re-analysis was carried out to see if the decisions made in the 1990s were correct. It was found that the site selection and the measures applied had been justified. The jetties in the port favour expansion of the beach west of the port. The vessels have been served without problems and the navigation channels do not need frequent dredging. A new road, connecting the factories and the port leaves residential areas undisturbed. [ABSTRACT FROM AUTHOR]

Coelho, C.; Ferreira, M., and Marinho, B., 2020. Numerical modelling of artificial sediment nourishment impacts. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 209–213. Coconut Creek (Florida), ISSN 0749-0208. In general, coastal erosion problems are related to significant sediments deficits. A possible coastal erosion mitigation strategy involves restoring the sediments balance through artificial nourishments. However, the complexity of the physical processes in the coastal zones challenges the numerical tools prediction capacity. This is usually overcome through numerical modelling of the shoreline evolution and the cross-shore profile along time, as an attempt to anticipate the performance of nourishments operations. The coastal morphology depends on the sediments dynamics and the incident wave climate is considered the main modelling agent responsible for the potential sediment transport capacity. The cross-shore sediment transport is usually associated to the shortterm behaviour of the morphological evolution of the beach (seasonal changes) and the longshore sediment transport is related to the long-term changes (towards an equilibrium state). Typically, these distinct sediment transport components are studied and modelled separately due to the incompatibility of their time scales of interest. This work was developed to numerically model the impact of artificial nourishments. LTC (Long-Term Configuration, Coelho, 2005) and CS-model (Larson et al., 2016) were both applied to analyse the spatial and temporal distribution of sediments induced by artificial nourishments along and across the shore, considering different intervention scenarios. LTC was applied to evaluate the nourishments impact in the shoreline evolution and to quantify the volume of nourished sediments in different longshore locations along time. The CS-model was used to analyse the performance of multiple intervention scenarios, varying the cross-shore location, frequency and volume of the artificial nourishments. The performance of this type of intervention generally represents a smaller shoreline retreat and an increase of the cross-shore profile volumes during a limited period of time. The project results aim to increase numerical modelling capabilities, helping on the selection of optimal artificial nourishment schemes and the establishment of more efficient coastal management policies. [ABSTRACT FROM AUTHOR]

Coughlan, C., Vincent, C.E., Dolphin, T.J. and Rees, J.M., 2007. Effects of tidal stage on the wave climate inshore of a sandbank. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 751 – 756. Gold Coast, Australia, ISSN 0749.0208 Modelling of the processes that link the movements of offshore sandbanks to erosion and accretion of neighbouring beaches was undertaken to improve understanding of the links between sandbanks and beaches in order to inform coastal management. The effect of varying tidal stage on the wave climate inshore of a sandbank was examined using the TELEMAC suite of numerical models. Longshore sediment transport was calculated using the CERC formula to investigate changes to the magnitude and pattern of coastal erosion/accretion according to tidal stage using waves from two of the most frequent directions. Tidal stage has a significant impact on the inshore wave climate, varying wave heights by up to 0.5 m and increasing tenfold the magnitude of the longshore sediment transport. Tidal elevation appears to play a more important role than the tidal currents, with wave heights and longshore sediment transport maximum at high water. The pattern of alongshore erosion and accretion varies more strongly with wave direction than tidal stage. [ABSTRACT FROM AUTHOR]

Vila-Concejo, A., Short, A.D., Hughes, M.G. and Ranasinghe, R., 2007. Flood-tide Delta Morphodynamics and Management Implications, Port Stephens, Australia. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 705 – 709. Gold Coast, Australia, ISSN 0749.0208 Port Stephens is a drowned river valley estuary located in SE Australia. Its flood-tide delta is part of the morphological transition between the wave-dominated open coast and the tide-dominated estuarine environment. The sand surface of the flood-tide delta is subject to episodic disturbance by large ocean waves that penetrate into Port Stephens. Moreover, the flood-tide delta is a dynamic feature that responds to variations in the forcing mechanisms. Shoal Bay, Nelson Bay and Jimmy's Beach located on both sides of the entrance have experienced severe erosion for the last 40 years, resulting in expensive shoreline management controls. The evolution of these beaches has been linked to the flood-tide delta morphodynamics. Most of the morphologic features in outer Port Stephens have undergone erosion processes during at least the last 40 years. Yacaaba Head seems to be the only morphologic unit that has undergone sedimentary accretion. Results from numerical models obtained by other authors found eastward directed sediment transport occurring on the eroding beaches. Field measurements and observations show westward sediment transport. Further studies to identify the sediment exchange mechanisms and controls are needed to clarify the morphodynamics of the outer part of Port Stephens. [ABSTRACT FROM AUTHOR]

Silva, R., Coelho, C., Veloso-Gomes, F. and Taveira-Pinto, F., 2007. Dynamic numerical simulation of medium term coastal evolution of the West Coast of Portugal. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 263 – 267. Gold Coast, Australia, ISSN 0749.0208 Coastal erosion is a common problem within Europe. The main causes of this phenomenon are the generalised sea-level rise, the coastal interventions (defence and harbour structures), which cause serious perturbations in the littoral drift system, the littoral occupation and the river sediment supply reduction caused by dams, dredging and fluvial regularisation. Numerical models are helpful tools in future planning and management of coastal policies, by allowing the projection and analysis of different scenarios of medium term coastal evolution. A numerical coastline evolution model (LTC – Long Term Configuration) is being developed to support coastal zone planning and management in relation to erosion problems. The model simulates the dynamic variability of sandy beaches, where the alongshore sediment transport is controlled by waves, currents, wind, water level, sediments' sources and sinks and sediments' properties. The model also simulates different coastal interventions (groins and breakwaters, longitudinal revetments, artificial nourishments, river sediments supply). It may be applied to extensive coastal areas up to one hundred years time scale. In this paper, LTC will be used in the evaluation of the relative importance of each of the identified causes of coastal erosion at the Northwest Portuguese coast at a medium term horizon. Special attention will be given to the discussion of common coastal defence interventions influence in the littoral drift system and impact in what concerns erosion. [ABSTRACT FROM AUTHOR]

This study investigates the changes in circulation, sediment resuspension, sediment flux and salinity that accompany 'winter storms' in the Atchafalaya Bay region, events that occur 20 to 30 times each yearbetween October and April. NOAA-14 satellite reflectance imagery andtime-series measurements of winds, water levels, current velocity and turbidity demonstrate that wind direction and speed are the major controlling factors for circulation, sediment transport and suspended sediment concentrations. East winds (occurring 62% of the time) induce a westward flow of sediment-laden Atchafalaya river water along thecoast. West winds reverse the direction of plume movement and increase the size of the plume, partly as a result of Ekman processes. The strong north winds, characteristic of winter storms, cause rapid flushing from the shallow bays (30-50% of volume) and water level changesin excess of 1 meter. Seaward of these bays, a large sediment plume (180 km alongshore, 75 km offshore) is produced by the wind-wave resuspension of bottom sediments and the wind-forced seaward transport ofbay and inner shelf waters. Water and sediment flux is primarily southeastward, temporarily disrupting the westward flow of river water along the coast. In the Vermilion-Cote Blanche Bay system, northwest winds maximize sediment resuspension and the seaward flux of sediment-laden river and bay water. The storm-related sediment resuspension and transport reduces the rapidity of delta development and deposition in these bays and re-distributes sediment along the inner shelf. [ABSTRACT FROM AUTHOR]

This study investigates the changes in circulation, sediment resuspension, sediment flux and salinity that accompany 'winter storms' in the Atchafalaya Bay region, events that occur 20 to 30 times each yearbetween October and April. NOAA-14 satellite reflectance imagery andtime-series measurements of winds, water levels, current velocity and turbidity demonstrate that wind direction and speed are the major controlling factors for circulation, sediment transport and suspended sediment concentrations. East winds (occurring 62% of the time) induce a westward flow of sediment-laden Atchafalaya river water along thecoast. West winds reverse the direction of plume movement and increase the size of the plume, partly as a result of Ekman processes. The strong north winds, characteristic of winter storms, cause rapid flushing from the shallow bays (30-50% of volume) and water level changesin excess of 1 meter. Seaward of these bays, a large sediment plume (180 km alongshore, 75 km offshore) is produced by the wind-wave resuspension of bottom sediments and the wind-forced seaward transport ofbay and inner shelf waters. Water and sediment flux is primarily southeastward, temporarily disrupting the westward flow of river water along the coast. In the Vermilion-Cote Blanche Bay system, northwest winds maximize sediment resuspension and the seaward flux of sediment-laden river and bay water. The storm-related sediment resuspension and transport reduces the rapidity of delta development and deposition in these bays and re-distributes sediment along the inner shelf. [ABSTRACT FROM AUTHOR]

About fifty kilometers of lagoon coast in Majuro Atoll is suffering erosion, which is induced by human activities including aggregate excavating and building causeways, artificial channels, landfill and other constructions. The west longshore sediment transportation on lagoon coast is significant for stability of lagoon shore of the west atoll. The lagoon coast erosion on the west atoll is induced by development on the east atoll. Distribution of beachrock demonstrates former existence of a continuous land on the south rim. The causeway has not caused sea level rising in lagoon. Openings on the south rim should not be made, as these will induce severe erosion. Reforming lagoon coastal constructions is proposed. [ABSTRACT FROM AUTHOR]

Under storm conditions, often more than 0.5 million tons of mud and fine sand are deposited in less than one week in the in-land part (Maasmond) of the access channels to the Europoort harbors at the mouth of the Rotterdam Waterway. The majority of this material comes from the sea. Transport of this material has previously escaped detection, and a satisfactory physical description of these massive-sedimentation events is lacking. A mechanism is proposed that can explain these sedimentation events. In the coastal zone, combined wave-current flowswinnow muds and fine sands from the bottom, generate sediment-induced stratification in a layer a few decimeters thick, and transport these wave-induced near-bottom high-concentration suspension layers (WI-HCSLs) with the near-bottom water currents. In a large area residual flows in the lower portion of the water column are directed to the Maasmond, because of water-density differences from the relatively large Rhine fresh-water outflow. In a few days, sediments from a vast area are thus transported near the bottom to the Maasmond. Once in the Maasmond, they settle due to a considerable reduction of wave action and tidal current velocities there. Due to the high deposition rates, fluid-mud layers are formed that spread and consolidate slowly. A simple data-driven particle-deposition model simulates the transport anddeposition of suspended sediment that enters the sedimentation area.The description of the sedimentation in the Maasmond with WI-HCSLs and with the particle-deposition model, is supported by a wide range of observations in this case study, such as sediment composition, and the positive correlation of sedimentation amounts with wave energy and fresh-water outflow. Further support is given by numerical examplesbased on transport processes and field data. [ABSTRACT FROM AUTHOR]

The Belgian coast is protected for 50% by hard constructions including slanting seawalls and groins. Most of them were built after the extremely severe 1953 storm. The other 50% of the coast consist of dune-belts and beaches. More than a century ago a groin field was implanted in front of the dune barrier protecting the coastal plain. But both nature and man's activities encroached on this natural defense and by the forties several east coast resorts were left without a beach at high water. Hard structures did not provide adequate protection, they even seemed to worsen problems, and yet, some new techniques like the use of the HARO were welcome innovations. The extension of Zeebrugge harbour provided an opportunity to consider artificial nourishment using the dredgings. The approach provided some satisfaction but recharges were necessary. Meanwhile the west coast started to show signs of erosion. Various beach protection and restoration methods were tested but discarded for a variety of reasons. Then nourishment with afeeder berm was decided upon for the De Haan sector and has yielded excellent results. The paper, while focusing on Belgian approaches, reviews alternative approaches such as artificial reefs and dewatering, but also methods that call upon Nature to rebuild beaches, among which Berosin and Beachbuilder. [ABSTRACT FROM AUTHOR]