One line modeling of bayed beach | |
| Author | Tanuspong Pokavanich |
| Call Number | AIT Thesis no.WM-02-03 |
| Subject(s) | Models and modelmaking Waves--Diffraction |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | The bay beach exists where the waves arrive persistently from an oblique direction to the general coast with the presence of headlands. The universal final static equilibrium bayed shape, crenulated bay shape, has been proposed by many researchers for decades. While its evolution was examined by the numerical simulation technique using the modified one-line model by combining the Cartesian and Polar coordinate. To improve the numerical model calculation potential of shoreline response to irregular predominant wave form, the present work is started from the model sensitivity test. The analysis reveals the fact that the mismatch between the laboratory and simulation come from the wave diffraction calculation scheme. The calculation scheme of wave breaking angle behind the coastal structure is modified using two approaches. The straightforward approach and the extracted empirical formula are both applied onto the model which more or less generates the similar satisfactory result. Good agreement between computed equilibrium bayed shape and the experimented one is achieved by the introduction of process acceleration, shadow zone reduction and the extension of the upcoast headland. The computed equilibrium state then reach at the same time of laboratory result. Moreover, the model is generalized by insertion of another downcoast hooked zone with Polar coordinate. The new coordinate enables the model to simulate left and right side incoming wave directions. The pattern of beach change from the case studies show the tentative location, magnitude and timing of erosion and accretion by the effect of alter incoming wave angle. Lastly, the dynamic equilibrium bay shape is studied. The development of the shoreline response to the various form of sediment supply, point and distributed source, are investigated. The comparison of simulated bay shape with the analytical solution reveals fairly agreement. The introduction of onshore sediment transport provides a bit of help in improving the degree of matching. It is asserted that the amount, location and timing of sediment supply govern the new dynamic equilibrium shapes and their development. It is concluded that the higher magnitude of sediment supply catalyzed the bay evolution. |
| Year | 2003 |
| 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 ;Luketina, David A. ; |
| Scholarship Donor(s) | Royal Thai Government, Thailand; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2003 |