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Giuseppe Roberto Tomasicchio - One of the best experts on this subject based on the ideXlab platform.
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General model for estimation of Longshore Transport at shingle/mixed beaches
Coastal Engineering Proceedings, 2017Co-Authors: Giuseppe Roberto Tomasicchio, Giuseppe Barbaro, Felice D'alessandro, Francesco Ciardulli, Antonio Francone, Sahameddin Mahmoudi KurdistaniAbstract:In the present study, the accuracy of the GLT model (Tomasicchio et al., 2013) has been verified for the estimation of the Longshore Transport (LT) at shingle/mixed beaches. In order to verify the suitability of the GLT model in determining LT estimates at shingle beaches, without any further calibration, the comparison between the LT predictions and observations from two field data sets (Chadwick, 1989; Nicholls and Wright, 1991) has been considered. The comparison showed that the GLT predicted LT rates within a factor of 2 of the observed values. The predictive capability of the GLT has been also verified against an alternative general formula for the LT estimation at shingle beaches (Van Rijn, 2014). In addition, the suitability of the GLT model, even for the mixed beach case, has been assessed by means of the comparison between the LT prediction and the observation from a field experiment on a mixed sand and gravel beach at Hawke’s Bay, on the east coast of New Zealand (Komar, 2010).
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Longshore Transport at shingle beaches an independent verification of the general model
Coastal Engineering, 2015Co-Authors: Giuseppe Roberto Tomasicchio, Felice Dalessandro, Giuseppe Barbaro, Elena Musci, Teresa M De GiosaAbstract:Abstract The General Longshore Transport (GLT) model (Tomasicchio et al., 2013) and the Van Rijn (2014) expression represent the only two available general formulae in literature for the estimation of Longshore Transport (LT) at sand, gravel and shingle beaches. The GLT model is based on an energy flux approach combined with an empirical relationship between the wave induced forcing and the number of moving elements. An independent verification of the GLT model is performed for the estimation of the total (bulk) LT at shingle beaches. Without any further calibration, the suitability of the GLT model, even for the shingles beach case, is assessed by means of the comparison between the LT predictions and the observations from two field data sets (Chadwick, 1989; Nicholls and Wright, 1991). In most cases the GLT predicts LT rates within a factor of 2 of the observed values. The predictive capability of the GLT model is tested with reference to two different formulae recently proposed in literature (Mil-Homens et al., 2013; Van Rijn, 2014). It is shown that the GLT model gives a better agreement with the observations (Chadwick, 1989; Nicholls and Wright, 1991; Van Hijum and Pilarczyk, 1982) with respect to the other considered formulae. Moreover, long term (annual) field data (Van Wellen et al., 2000) have been used for a further verification. In addition, the GLT model confirms to have a better agreement even for the LT at dynamically stable berm reshaping breakwaters (Lamberti and Tomasicchio, 1997; Van der Meer and Veldman, 1992).
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general Longshore Transport model
Coastal Engineering, 2013Co-Authors: Giuseppe Roberto Tomasicchio, Felice Dalessandro, Giuseppe Barbaro, Giovanni MalaraAbstract:Abstract In the present paper a general Longshore Transport (LT) model is proposed after a re-calibration of the model originally introduced by Lamberti and Tomasicchio (1997) based on a modified stability number, N s ⁎⁎ , for stone mobility at reshaping or berm breakwaters. N s ⁎⁎ resembles the traditional stability number ( Ahrens, 1987 ; van der Meer, 1988) taking into account the effects of a non-Rayleighian wave height distribution at shallow water ( Klopman and Stive, 1989 ), wave steepness, wave obliquity, and nominal diameter of the units. Nine high-quality data sets from field and laboratory experiments have been considered to extend the validity of the original model for a wider mobility range of the units: from stones to sands. The predictive capability of the proposed model has been verified against the most popular formulae in literature for the LT estimation of not cohesive units at a coastal body. The comparison showed that the model gives a better agreement with the physical data with respect to the other investigated formulae. The proposed Transport model presents a main advantage with respect to other formulae: it can represent an engineering tool suitable for a large range of conditions, from sandy beaches till reshaping breakwaters.
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stone mobility and Longshore Transport at reshaping breakwaters
Coastal Engineering, 1997Co-Authors: Alberto Lamberti, Giuseppe Roberto TomasicchioAbstract:Abstract Physical model tests have been performed in two different wave flumes to analyse the threshold of stone movement and quantify the frequency and length of displacements due to head-on wave attacks at a reshaping breakwater. Data on stone movements were obtained from the observation of cumulative displacements at the end of each wave attack and from video records during the attack. Threshold conditions, frequency of movement and displacement length are expressed as function of a suitably modified stability number. A simple model is defined relating Longshore Transport due to oblique wave attack to stone mobility. The Transport model is based on the assumption that movement statistics is affected by obliquity only through the appropriate mobility index and that stones move during up- and down-rush in the direction of incident and reflected waves. Without any calibration, results compare favourably with experimental data available in literature in the range of low mobility conditions where movement statistics was observed. A calibration is provided in order to obtain an accurate Transport formula valid in a wide mobility range i.e. for reshaping breakwaters and up to gravel beaches.
Leo C Van Rijn - One of the best experts on this subject based on the ideXlab platform.
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a simple general expression for Longshore Transport of sand gravel and shingle
Coastal Engineering, 2014Co-Authors: Leo C Van RijnAbstract:Abstract Longshore Transport of sand, gravel and shingle has been studied using field and laboratory data over a wide range of conditions. A detailed model (CROSMOR) for cross-shore and Longshore sediment Transport has been used to determine the effects of wave period, grain size, beach/surf zone slope and type of waves (wind waves or swell waves). The Longshore Transport was found to be proportional to wave height to the power 3.1 (≈ H3.1), to grain size to the power − 0.6 (≈ d50− 0.6) and to beach slope to the power 0.4 (≈ tanβ0.4). Regular swell waves yield much larger (factor 1.5) Longshore Transport rates than irregular wind waves of the same height. It is proposed to take this effect into account by a swell correction factor. Based on all results, a new simple and general (dimensionally correct) expression for Longshore Transport of sand, gravel and shingle beaches with grain sizes between 0.1 and 100 mm has been derived. Short-term and long-term field data of sand, gravel and shingle have been used for verification. In most cases the predicted Longshore Transport rates are within a factor of 2 of the measured values. The CERC and Kamphuis formulas have also been tested.
Giuseppe Barbaro - One of the best experts on this subject based on the ideXlab platform.
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General model for estimation of Longshore Transport at shingle/mixed beaches
Coastal Engineering Proceedings, 2017Co-Authors: Giuseppe Roberto Tomasicchio, Giuseppe Barbaro, Felice D'alessandro, Francesco Ciardulli, Antonio Francone, Sahameddin Mahmoudi KurdistaniAbstract:In the present study, the accuracy of the GLT model (Tomasicchio et al., 2013) has been verified for the estimation of the Longshore Transport (LT) at shingle/mixed beaches. In order to verify the suitability of the GLT model in determining LT estimates at shingle beaches, without any further calibration, the comparison between the LT predictions and observations from two field data sets (Chadwick, 1989; Nicholls and Wright, 1991) has been considered. The comparison showed that the GLT predicted LT rates within a factor of 2 of the observed values. The predictive capability of the GLT has been also verified against an alternative general formula for the LT estimation at shingle beaches (Van Rijn, 2014). In addition, the suitability of the GLT model, even for the mixed beach case, has been assessed by means of the comparison between the LT prediction and the observation from a field experiment on a mixed sand and gravel beach at Hawke’s Bay, on the east coast of New Zealand (Komar, 2010).
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Longshore Transport at shingle beaches an independent verification of the general model
Coastal Engineering, 2015Co-Authors: Giuseppe Roberto Tomasicchio, Felice Dalessandro, Giuseppe Barbaro, Elena Musci, Teresa M De GiosaAbstract:Abstract The General Longshore Transport (GLT) model (Tomasicchio et al., 2013) and the Van Rijn (2014) expression represent the only two available general formulae in literature for the estimation of Longshore Transport (LT) at sand, gravel and shingle beaches. The GLT model is based on an energy flux approach combined with an empirical relationship between the wave induced forcing and the number of moving elements. An independent verification of the GLT model is performed for the estimation of the total (bulk) LT at shingle beaches. Without any further calibration, the suitability of the GLT model, even for the shingles beach case, is assessed by means of the comparison between the LT predictions and the observations from two field data sets (Chadwick, 1989; Nicholls and Wright, 1991). In most cases the GLT predicts LT rates within a factor of 2 of the observed values. The predictive capability of the GLT model is tested with reference to two different formulae recently proposed in literature (Mil-Homens et al., 2013; Van Rijn, 2014). It is shown that the GLT model gives a better agreement with the observations (Chadwick, 1989; Nicholls and Wright, 1991; Van Hijum and Pilarczyk, 1982) with respect to the other considered formulae. Moreover, long term (annual) field data (Van Wellen et al., 2000) have been used for a further verification. In addition, the GLT model confirms to have a better agreement even for the LT at dynamically stable berm reshaping breakwaters (Lamberti and Tomasicchio, 1997; Van der Meer and Veldman, 1992).
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general Longshore Transport model
Coastal Engineering, 2013Co-Authors: Giuseppe Roberto Tomasicchio, Felice Dalessandro, Giuseppe Barbaro, Giovanni MalaraAbstract:Abstract In the present paper a general Longshore Transport (LT) model is proposed after a re-calibration of the model originally introduced by Lamberti and Tomasicchio (1997) based on a modified stability number, N s ⁎⁎ , for stone mobility at reshaping or berm breakwaters. N s ⁎⁎ resembles the traditional stability number ( Ahrens, 1987 ; van der Meer, 1988) taking into account the effects of a non-Rayleighian wave height distribution at shallow water ( Klopman and Stive, 1989 ), wave steepness, wave obliquity, and nominal diameter of the units. Nine high-quality data sets from field and laboratory experiments have been considered to extend the validity of the original model for a wider mobility range of the units: from stones to sands. The predictive capability of the proposed model has been verified against the most popular formulae in literature for the LT estimation of not cohesive units at a coastal body. The comparison showed that the model gives a better agreement with the physical data with respect to the other investigated formulae. The proposed Transport model presents a main advantage with respect to other formulae: it can represent an engineering tool suitable for a large range of conditions, from sandy beaches till reshaping breakwaters.
J S Schoonees - One of the best experts on this subject based on the ideXlab platform.
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annual variation in the net Longshore sediment Transport rate
Coastal Engineering, 2000Co-Authors: J S SchooneesAbstract:Abstract The annual variation in the net Longshore sediment Transport rates at three South African and at one North African site is investigated. The net rates at these sites, given in the first table, show large variations. It was found that measurements of Longshore Transport rates should be conducted continuously for 5–8 years in order to obtain an accurate value (within 10%) of the true long-term mean net Longshore Transport rate. A second table was drawn up, which can be applied to determine the range in which the true mean rate will fall if measurements were done over a shorter period than the recommended 5–8 years. It is reasonable to expect that the conclusions are widely applicable, especially for exposed sites. It is recommended that an accurate assessment of the long-term mean net Longshore Transport rate at a site can best be made cost-effectively by doing limited site-specific measurements, calibrating the best Longshore Transport formula for the particular site, and predicting the Transport rates using a representative wave climate.
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improvement of the most accurate Longshore Transport formula
25th International Conference on Coastal Engineering, 1997Co-Authors: J S Schoonees, A K TheronAbstract:The ability to predict the Longshore sediment Transport rate accurately is essential for many coastal engineering applications. Because of the existance of a large number of existing Longshore Transport formulae, it is important to know which formula to use/apply. Thus, the most universally applicable formula was identified and tested against a comprehensive data set. This formula (Kamphuis formula) was also re-calibrated and guidance is given regarding its use.
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accuracy and applicability of the spm Longshore Transport formula
24th International Conference on Coastal Engineering, 1995Co-Authors: J S Schoonees, A K TheronAbstract:The ability to predict the time-averged Longshore sediment Transport rate accurately is essential for many coastal engineering applications. Because the Longshore Transport formula in the Shore Protection Manual (SPM; US Army, Corps of Engineers, 1984) is possibly the most widely used, it is important to know its accuracy. The aim of this paper is therefore to investigate the accuracy and applicability of this formula (the SPM formula). In addition, a number of variations to this formula are presented; these are also tested against a comprehensive data set. Finally, the SPM formula is re-calibrated and guidance is given regarding the use of this formula for coarse bed material.
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review of the field data base for Longshore sediment Transport
Coastal Engineering, 1993Co-Authors: J S Schoonees, A K TheronAbstract:Abstract A literature search was undertaken to collect field data on Longshore sediment Transport. This yielded a large number of data sets (273 points for bulk Transport rates) from a variety of sites around the world. Data are especially lacking for Transport rates exceeding 0.2 × 106 m3/year, significant wave heights higher than 1.8 m, sediment grain sizes coarser than 0.6 mm and beach slopes steeper than 0.06 (= 1 14 ). A point rating system was devised whereby the quality of the data could be assessed. The recording method and the accuracy thereof as well as the representativeness of the data were taken into account. It was found that the evaluation was done reasonably objectively and consistently. The data were divided into three categories. The highest score achieved in the evaluation was only 71% thus reflecting the difficulty of measuring Longshore Transport accurately. It is recommended that Longshore Transport formulae be calibrated against the data in the higher category (60% and better) and then be tested against all the other data. This will ensure that the formulae will be tested in as many different conditions and sites as possible without the lower quality data contributing to the calibration constants.
Felice Dalessandro - One of the best experts on this subject based on the ideXlab platform.
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Longshore Transport at shingle beaches an independent verification of the general model
Coastal Engineering, 2015Co-Authors: Giuseppe Roberto Tomasicchio, Felice Dalessandro, Giuseppe Barbaro, Elena Musci, Teresa M De GiosaAbstract:Abstract The General Longshore Transport (GLT) model (Tomasicchio et al., 2013) and the Van Rijn (2014) expression represent the only two available general formulae in literature for the estimation of Longshore Transport (LT) at sand, gravel and shingle beaches. The GLT model is based on an energy flux approach combined with an empirical relationship between the wave induced forcing and the number of moving elements. An independent verification of the GLT model is performed for the estimation of the total (bulk) LT at shingle beaches. Without any further calibration, the suitability of the GLT model, even for the shingles beach case, is assessed by means of the comparison between the LT predictions and the observations from two field data sets (Chadwick, 1989; Nicholls and Wright, 1991). In most cases the GLT predicts LT rates within a factor of 2 of the observed values. The predictive capability of the GLT model is tested with reference to two different formulae recently proposed in literature (Mil-Homens et al., 2013; Van Rijn, 2014). It is shown that the GLT model gives a better agreement with the observations (Chadwick, 1989; Nicholls and Wright, 1991; Van Hijum and Pilarczyk, 1982) with respect to the other considered formulae. Moreover, long term (annual) field data (Van Wellen et al., 2000) have been used for a further verification. In addition, the GLT model confirms to have a better agreement even for the LT at dynamically stable berm reshaping breakwaters (Lamberti and Tomasicchio, 1997; Van der Meer and Veldman, 1992).
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general Longshore Transport model
Coastal Engineering, 2013Co-Authors: Giuseppe Roberto Tomasicchio, Felice Dalessandro, Giuseppe Barbaro, Giovanni MalaraAbstract:Abstract In the present paper a general Longshore Transport (LT) model is proposed after a re-calibration of the model originally introduced by Lamberti and Tomasicchio (1997) based on a modified stability number, N s ⁎⁎ , for stone mobility at reshaping or berm breakwaters. N s ⁎⁎ resembles the traditional stability number ( Ahrens, 1987 ; van der Meer, 1988) taking into account the effects of a non-Rayleighian wave height distribution at shallow water ( Klopman and Stive, 1989 ), wave steepness, wave obliquity, and nominal diameter of the units. Nine high-quality data sets from field and laboratory experiments have been considered to extend the validity of the original model for a wider mobility range of the units: from stones to sands. The predictive capability of the proposed model has been verified against the most popular formulae in literature for the LT estimation of not cohesive units at a coastal body. The comparison showed that the model gives a better agreement with the physical data with respect to the other investigated formulae. The proposed Transport model presents a main advantage with respect to other formulae: it can represent an engineering tool suitable for a large range of conditions, from sandy beaches till reshaping breakwaters.
