Model for Predicting Topographic Changes on Coast Composed of Sand of Mixed Grain Size and Its Applications

Tsung-Hsien²,

Lin³

et al. 2016

J. JSCE Ser. B3

Self Cite

Golden Beach in south Taiwan is widely known and has been attracting many beachgoers. In recent years, this beach has been eroded and measures to restore the sandy beach are required. The cause of the beach erosion was investigated on the basis of bathymetric survey data. In the study area, northward longshore sand transport, which was induced by the wave-sheltering effect of Anping Harbor, prevails, and the rate of transport was estimated to be 1.25×10 5 m 3 /yr with the conditions of the depth of closure (h c ) of -6 m, the berm height (h R ) of 2.2 m, and the characteristic height of beach changes (h) of 9.2 m.

Section: Discussionmentioning

confidence: 99%

Section: Bathymetry and Bathymetric Changesmentioning

confidence: 99%

Beach Erosion on Golden Beach in South Tiwan

Tsung-Hsien²,

Lin³

et al. 2016

J. JSCE Ser. B3

Self Cite

“…To study the concept of the MGB method, the contour-line-change model considering changes in grain size (Uda and Serizawa, 2010) was used. Consider a dynamic equilibrium condition in which constant longshore sand transport continuously develops before the blockage of leftward longshore sand transport.…”

Section: Calculation To Study Concept Of Mgb Methods Calculation Condimentioning

confidence: 99%

Moving Gravel Body Method to Control Downcoast Erosion

Ishikawa

Int. Conf. Coastal. Eng.

Miyahara³

2012

Self Cite

The concept of the moving gravel body (MGB) method, in which topographic changes are controlled by beach nourishment using gravel, was introduced, using the contour-line-change model considering changes in grain size. The model was applied to the Fuji coast, assuming that coarse materials were nourished on a straight coast wherein a predominant longshore sand transport develops. The grain size that is effective for the recovery and maintenance of the shoreline and that does not cause further downcoast erosion was d, which is 5-10 times larger than that of the original sand, d0.

“…The cross-shore transport of sand of mixed grain sizes can be modeled by expanding the concept of a single grain size as described in Uda and Serizawa (2010). The sorting of grain size populations, such as those of fine sand, medium and coarse sand, and gravel, can be modeled by introducing the equilibrium slope angle β c (k) , which corresponds to each grain size population k. In this case, a grain size population is assumed to have a single equilibrium beach slope with a characteristic grain size d (k) , for example, the median diameter of the grain size population.…”

Section: Numerical Modelmentioning

confidence: 99%

“…In this case, the prediction of the movement of materials with mixed grain sizes is needed. In this study, therefore, we first analyzed beach changes around this fishing port using past aerial photographs and bathymetric survey data, and beach changes were reproduced using the contour-line-change model considering changes in grain size (Uda and Serizawa, 2010). Then, the effect of measures was investigated using the model.…”

Section: Introductionmentioning

confidence: 99%

Beach Changes Around Dawu Fishing Port in Taiwan Caused by Obstruction of Longshore Sand Transport and Measures

Kumada

Int. Conf. Coastal. Eng.

Liu

2012

Self Cite

The Dawu fishing port breakwater has been extending since 1956 in Taitung City located in the southeast part of Taiwan, obstructing southward longshore sand transport. Because of the blockage of longshore sand transport at this fishing port, severe downcoast erosion occurred, resulting in the wave overtopping damage to Route No. 9 extending along the coastline, and urgent measures were required to enhance the safety of the route. As measures, beach nourishment using coarse materials including gravel produced from the construction of a road tunnel was planned, as well as the construction of groins on the downcoast. We first analyzed beach changes around this fishing port using past aerial photographs and bathymetric survey data, and beach changes were reproduced using the contour-line-change model considering changes in grain size. Then, the effect of measures was investigated using the model.