| Author | Thamnoon Rasmeemasmuang |
| Call Number | AIT Thesis no. WM-00-04 |
| Subject(s) | Coast changes
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| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | When predominant waves obliquely arrive to the coast containing headlands, the shoreline will distinctly be sculptured as an crenulate shaped bay. This conspicuous because of the limitation of coordinates. In order to improve the numerical model based on "one-line theory". The present work originally proposed the combination of the cartesian and polar coordinated, so the the model can response the whole shoreline configuration. Polar coordinates represent shoreline positions in the hooked zone, whereas Cartesian coordinates for unhooked shoreline. The Shoreline change model is a sophisticated method of performing and sediment budget calculation based on the continuity equation of sediment. The so-called CERC formula is employed to evaluate the longshore sediment transport rate induced by obliquely incident waves and longshore current. Experimental data of Crenulate shaped bay for wave angles from 10˚- 60˚are used to verify the formulated model; furthermore, the parabolic bay-shaped equations are applied to compare the static equilibrium state of shoreline. The present model can effectively simulate the time-varying shoreline. At the ultimate state the calculated shoreline in hooked zone fits the measured data better than the parabolic bay-shaped equations when the wave obliquity is larger, e.g. 45˚ and 60˚ nevertheless, as alike situation the shoreline in shadow zone of unhooked zone partition is slightly more distorted. The overall precision of the prediction is very good especially for small wave angles.
Two different components of the model, which are irregular diffraction and Kamphuis's formula of longshore sediment transport rate, are likewise employed instead of precedence in order to study the effects of model components and increase the model capability, It was found that the static equilibrium bayed shape is slightly depended on the diffraction model.
A new formula of longshore sediment transport rate is derived by means of taking the effect of longshore current into account. The additional calibration parameters and the part of sediment transport caused by longshore current are combined into the Kamphuis's script formula. A newly modified formula is more flexible owing to the calibration parameters as well as gives the better fitted shoreline around upcoast headland because of the existence of the term performing the sediment transport induced by long shore current.
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| Year | 2001 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Sutat Weesakul |
| Examination Committee(s) | Suphat Vongvisessomjai ;Izumi, Norihiro |
| Scholarship Donor(s) | Burapha University, Thailand |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2001 |