scholarly journals LONGSHORE SEDIMENT TRANSPORT ON DEAN BEACH PROFILES

1984 ◽  
Vol 1 (19) ◽  
pp. 101
Author(s):  
William G. McDougal ◽  
Robert T. Hudspeth
Keyword(s):  
Sediment Transport ◽  
Eddy Viscosity ◽  
Viscosity Coefficient ◽  
Strength Parameter ◽  
Longshore Current ◽  
Transport Models ◽  
Longshore Sediment Transport ◽  
Equilibrium Profile ◽  
Eddy Viscosity Coefficient ◽  
Stress Models

Natural beaches exhibit an equilibrium profile that is planar nearshore and non-planar, concave-up offshore. The longshore current on these Dean equilibrium beaches is shown to depend on the location of the intersection between the planar and non-planar profiles and on the dimensionless mixing strength parameter if the eddy viscosity coefficient is linearly dependent on the distance offshore. The effect of the profile intersection on the longshore sediment transport rate is demonstrated for two energetics based sediment transport models; viz. the Bagnold and energetics stress models.

scholarly journals LONGSHORE CURRENT AND TRANSPORT ACROSS NON-SINGULAR EQUILIBRIUM BEACH PROFILES

1988 ◽  
Vol 1 (21) ◽  
pp. 104
Author(s):  
Kevin R. Bodge
Keyword(s):  
Sediment Transport ◽  
Longshore Current ◽  
Beach Profile ◽  
Infinite Slope ◽  
Profile Shape ◽  
Equilibrium Beach Profile ◽  
Longshore Sediment Transport ◽  
Beach Processes ◽  
Mathematical Expressions ◽  
Equilibrium Profile

The longshore current and longshore sediment transport distributions are described across an equilibrium beach profile comprised of an intersecting planar foreshore and a concave-up profile. Such a profile shape avoids the singularity associated with the infinite-slope at the shoreline described by traditional equilibrium profile forms and allows prediction of beach processes at and above the shoreline. The mathematical expressions which describe the distributions are simplified and can be more readily applied relative to expressions previously presented in the literature. The findings are in general agreement with similar previous analytic studies and indicate that the current and transport maxima are generally located at about the intersection of the planar and concave-up portions of the profile.

scholarly journals VERTICAL VARIATION OP UNDERTOW IN THE SURF ZONE

1988 ◽  
Vol 1 (21) ◽  
pp. 33 ◽  
Author(s):  
Akio Okayasu ◽  
Tomoya Shibayama ◽  
Kiyoshi Horikawa
Keyword(s):  
Laboratory Experiments ◽  
Eddy Viscosity ◽  
Surf Zone ◽  
Viscosity Coefficient ◽  
Laser Doppler Velocimeter ◽  
Vertical Variation ◽  
Two Component ◽  
The Mean ◽  
Eddy Viscosity Coefficient ◽  
The Vertical Distribution

In order to establish a model of the vertical distribution of the undertow, laboratory experiments were performed on uniform slopes of 1/20 and 1/30. The turbulent velocity in the surf zone including the area close to the bottom was measured by using a two-component laser doppler velocimeter. The distributions of the mean Reynolds stress and the mean eddy viscosity coefficient were calculated. Based on the experimental results, a model to predict the vertical profile of the undertow was presented.

scholarly journals In Use of Permeable Groin for Reducing Longshore Sediment Transport at Tanjung Bayang Beach of South Sulawesi

2018 ◽  
Vol 1 (2) ◽  
pp. 70-73 ◽  
Author(s):  
Hasdinar Umar ◽  
Sabaruddin Rahman ◽  
Chairul Paotonan ◽  
Ahmad Yasir Baeda
Keyword(s):  
Sediment Transport ◽  
Coastal Protection ◽  
Breaking Wave ◽  
Longshore Current ◽  
Surrounding Area ◽  
South Sulawesi ◽  
Longshore Sediment Transport ◽  
Reduction Coefficient ◽  
Before And After ◽  
Transport Analysis

Breaking wave near beaches is the main force to generate longshore currents, which moved the sediment at surrounding area. Due to its negative outcome, which are erosion and sedimentation, the need of longshore sediment transport analysis become very important. One of the tools for solving that problem is by using coastal protection structure such as permeable groin. Permeable groin may reduce the rate of longshore sediment transport respectively by changing the level of permeability of the groin itself. The objective of this research was to obtain analytical results of the longshore sediment transport reduction analysis by using permeable groins at Tanjung Bayang Beach of South Sulawesi. Reduction of sediment transport along the beach was analyzed by calculating reduction coefficient, which is the ratio between the longshore current before and after hitting the permeable groins. The result showed that with 40% of permeability, the groin can reduced longshore sediment transport at Tanjung Bayang Beach for almost 50%; from 341.37x103 m3/year to 170.68x103 m3/year.

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